Justice Scalia

delivered the opinion of the Court.

The Student Athlete Drug Policy adopted by School District 47J in the town of Vernonia, Oregon, authorizes random urinalysis drug testing of students who participate in the District’s school athletics programs. We granted certiorari to decide whether this violates the Fourth and Fourteenth Amendments to the United States Constitution.

I

A

Petitioner Vernonia School District 47J (District) operates one high school and three grade schools in the logging community of Vernonia, Oregon. As elsewhere in small-town America, school sports play a prominent role in the town’s life, and student athletes are admired in their schools and in the community.

Drugs had not been a major problem in Vernonia schools. In the mid-to-late 1980’s, however, teachers and administrators observed a sharp increase in drug use. Students began to speak out about their attraction to the drug culture, and to boast that there was nothing the school could do about it. Along with more drugs came more disciplinary problems. *649Between 1988 and 1989 the number of disciplinary referrals in Vernonia schools rose to more than twice the number reported in the early 1980’s, and several students were suspended. Students became increasingly rude during class; outbursts of profane language became common.

Not only were student athletes included among the drug users but, as the District Court found, athletes were the leaders of the drug culture. 796 F. Supp. 1354, 1357 (Ore. 1992). This caused the District’s administrators particular concern, since drug use increases the risk of sports-related injury. Expert testimony at the trial confirmed the deleterious effects of drugs on motivation, memory, judgment, reaction, coordination, and performance. The high school football and wrestling coach witnessed a severe sternum injury suffered by a wrestler, and various omissions of safety procedures and misexecutions by football players, all attributable in his belief to the effects of drug use.

Initially, the District responded to the drug problem by offering special classes, speakers, and presentations designed to deter drug use. It even brought in a specially trained dog to detect drugs, but the drug problem persisted. According to the District Court:

“[T]he administration was at its wits end and ... a large segment of the student body, particularly those involved in interscholastic athletics, was in a state of rebellion. Disciplinary actions had reached ‘epidemic proportions.’ The coincidence of an almost three-fold increase in classroom disruptions and disciplinary reports along with the staff’s direct observations of students using drugs or glamorizing drug and alcohol use led the administration to the inescapable conclusion that the rebellion was being fueled by alcohol and drug abuse as well as the student’s misperceptions about the drug culture.” Ibid.

At that point, District officials began considering a drug-testing program. They held a parent “input night” to dis*650cuss the proposed Student Athlete Drug Policy (Policy), and the parents in attendance gave their unanimous approval. The school board approved the Policy for implementation in the fall of 1989. Its expressed purpose is to prevent student athletes from using drugs, to protect their health and safety, and to provide drug users with assistance programs.

B

The Policy applies to all students participating in interscholastic athletics. Students wishing to play sports must sign a form consenting to the testing and must obtain the written consent of their parents. Athletes are tested at the beginning of the season for their sport. In addition, once each week of the season the names of the athletes are placed in a “pool” from which a student, with the supervision of two adults, blindly draws the names of 10% of the athletes for random testing. Those selected are notified and tested that same day, if possible.

The student to be tested completes a specimen control form which bears an assigned number. Prescription medications that the student is taking must be identified by providing a copy of the prescription or a doctor’s authorization. The student then enters an empty locker room accompanied by an adult monitor of the same sex. Each boy selected produces a sample at a urinal, remaining fully clothed with his back to the monitor, who stands approximately 12 to 15 feet behind the student. Monitors may (though do not always) watch the student while he produces the sample, and they listen for normal sounds of urination. Girls produce samples in an enclosed bathroom stall, so that they can be heard but not observed. After the sample is produced, it is given to the monitor, who checks it for temperature and tampering and then transfers it to a vial.

The samples are sent to an independent laboratory, which routinely tests them for amphetamines, cocaine, and marijuana. Other drugs, such as LSD, may be screened at the *651request of the District, but the identity of a particular student does not determine which drugs will be tested. The laboratory’s procedures are 99.94% accurate. The District follows strict procedures regarding the chain of custody and access to test results. The laboratory does not know the identity of the students whose samples it tests. It is authorized to mail written test reports only to the superintendent and to provide test results to District personnel by telephone only after the requesting official recites a code confirming his authority. Only the superintendent, principals, vice-principals, and athletic directors have access to test results, and the results are not kept for more than one year.

If a sample tests positive, a second test is administered as soon as possible to confirm the result. If the second test is negative, no further action is taken. If the second test is positive, the athlete’s parents are notified, and the school principal convenes a meeting with the student and his parents, at which the student is given the option of (1) participating for six weeks in an assistance program that includes weekly urinalysis, or (2) suffering suspension from athletics for the remainder of the current season and the next athletic season. The student is then retested prior to the start of the next athletic season for which he or she is eligible. The Policy states that a second offense results in automatic imposition of option (2); a third offense in suspension for the remainder of the current season and the next two athletic seasons.

C

In the fall of 1991, respondent James Acton, then a seventh grader, signed up to play football at one of the District’s grade schools. He was denied participation, however, because he and his parents refused to sign the testing consent forms. The Actons filed suit, seeking declaratory and in-junctive relief from enforcement of the Policy on the grounds that it violated the Fourth and Fourteenth Amendments to the United States Constitution and Article I, § 9, of the Ore*652gon Constitution. After a bench trial, the District Court entered an order denying the claims on the merits and dismissing the action. 796 F. Supp., at 1355. The United States Court of Appeals for the Ninth Circuit reversed, holding that the Policy violated both the Fourth and Fourteenth Amendments and Article I, § 9, of the Oregon Constitution. 23 F. 3d 1514 (1994). We granted certiorari. 513 U. S. 1013 (1994).

II

The Fourth Amendment to the United States Constitution provides that the Federal Government shall not violate “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures . . . .” We have held that the Fourteenth Amendment extends this constitutional guarantee to searches and seizures by state officers, Elkins v. United States, 364 U. S. 206, 213 (1960), including public school officials, New Jersey v. T L. O., 469 U. S. 325, 336-337 (1985). In Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 617 (1989), we held that state-compelled collection and testing of urine, such as that required by the Policy, constitutes a “search” subject to the demands of the Fourth Amendment. See also Treasury Employees v. Von Raab, 489 U. S. 656, 665 (1989).

As the text of the Fourth Amendment indicates, the ultimate measure of the constitutionality of a governmental search is “reasonableness.” At least in a case such as this, where there was no clear practice, either approving or disapproving the type of search at issue, at the time the constitutional provision was enacted,1 whether a particular search meets the reasonableness standard “ ‘is judged by balancing *653its intrusion on the individual’s Fourth Amendment interests against its promotion of legitimate governmental interests.’” Skinner, supra, at 619 (quoting Delaware v. Prouse, 440 U. S. 648, 654 (1979)). Where a search is undertaken by law enforcement officials to discover evidence of criminal wrongdoing, this Court has said that reasonableness generally requires the obtaining of a judicial warrant, Skinner, supra, at 619. Warrants cannot be issued, of course, without the showing of probable cause required by the Warrant Clause. But a warrant is not required to establish the reasonableness of all government searches; and when a warrant is not required (and the Warrant Clause therefore not applicable), probable cause is not invariably required either. A search unsupported by probable cause can be constitutional, we have said, “when special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable.” Griffin v. Wisconsin, 488 U. S. 868, 873 (1987) (internal quotation marks omitted).

We have found such “special needs” to exist in the public school context. There, the warrant requirement “would unduly interfere with the maintenance of the swift and informal disciplinary procedures [that are] needed,” and “strict adherence to the requirement that searches be based on probable cause” would undercut “the substantial need of teachers and administrators for freedom to maintain order in the schools.” T L. O., 469 U. S., at 340, 341. The school search we approved in T L. 0., while not based on probable cause, was based on individualized suspicion of wrongdoing. As we explicitly acknowledged, however, “‘the Fourth Amendment imposes no irreducible requirement of such suspicion,’ ” id., at 342, n. 8 (quoting United States v. Martinez-Fuerte, 428 U. S. 543, 560-561 (1976)). We have upheld sus-picionless searches and seizures to conduct drug testing of railroad personnel involved in train accidents, see Skinner, supra; to conduct random drug testing of federal customs officers who carry arms or are involved in drug interdiction, *654see Von Raab, supra; and to maintain automobile checkpoints looking for illegal immigrants and contraband, Martinez-Fuerte, supra, and drunk drivers, Michigan Dept. of State Police v. Sitz, 496 U. S. 444 (1990).

1 — 1 1 — 1

The first factor to be considered is the nature of the privacy interest upon which the search here at issue intrudes. The Fourth Amendment does not protect all subjective expectations of privacy, but only those that society recognizes as “legitimate.” T L. O., 469 U. S., at 338. What expectations are legitimate varies, of course, with context, id., at 337, depending, for example, upon whether the individual asserting the privacy interest is at home, at work, in a car, or in a public park. In addition, the legitimacy of certain privacy expectations vis-a-vis the State may depend upon the individual’s legal relationship with the State. For example, in Griffin, supra, we held that, although a “probationer’s home, like anyone else’s, is protected by the Fourth Amendment,” the supervisory relationship between probationer and State justifies “a degree of impingement upon [a probationer’s] privacy that would not be constitutional if applied to the public at large.” 483 U. S., at 873, 875. Central, in our view, to the present case is the fact that the subjects of the Policy are (1) children, who (2) have been committed to the temporary custody of the State as schoolmaster.

Traditionally at common law, and still today, unemanci-pated minors lack some of the most fundamental rights of self-determination — including even the right of liberty in its narrow sense, i. e., the right to come and go at will. They are subject, even as to their physical freedom, to the control of their parents or guardians. See 59 Am. Jur. 2d, Parent and Child §10 (1987). When parents place minor children in private schools for their education, the teachers and administrators of those schools stand in loco parentis over the children entrusted to them. In fact, the tutor or schoolmas*655ter is the very prototype of that status. As Blackstone describes it, a parent “may . . . delegate part of his parental authority, during his life, to the tutor or schoolmaster of his child; who is then in loco parentis, and has such a portion of the power of the parent committed to his charge, viz. that of restraint and correction, as may be necessary to answer the purposes for which he is employed.” 1 W. Blackstone, Commentaries on the Laws of England 441 (1769).

In I L. O. we rejected the notion that public schools, like private schools, exercise only parental power over their students, which of course is not subject to constitutional constraints. 469 U. S., at 336. Such a view of things, we said, “is not entirely ‘consonant with compulsory education laws/ ” ibid. (quoting Ingraham v. Wright, 430 U. S. 651, 662 (1977)), and is inconsistent with our prior decisions treating school officials as state actors for purposes of the Due Process and Free Speech Clauses, T L. O., supra, at 336. But while denying that the State’s power over schoolchildren is formally no more than the delegated power of their parents, T. L. O. did not deny, but indeed emphasized, that the nature of that power is custodial and tutelary, permitting a degree of supervision and control that could not be exercised over free adults. “[A] proper educational environment requires close supervision of schoolchildren, as well as the enforcement of rules against conduct that would be perfectly permissible if undertaken by an adult.” 469 U. S., at 339. While we do not, of course, suggest that public schools as a general matter have such a degree of control over children as to give rise to a constitutional “duty to protect,” see DeShaney v. Winnebago County Dept. of Social Servs., 489 U. S. 189, 200 (1989), we have acknowledged that for many purposes “school authorities ac[t] in loco parentis,” Bethel School Dist. No. 403 v. Fraser, 478 U. S. 675, 684 (1986), with the power and indeed the duty to “inculcate the habits and manners of civility,” id., at 681 (internal quotation marks omitted). Thus, while children assuredly do not “shed their constitutional *656rights ... at the schoolhouse gate,” Tinker v. Des Moines Independent Community School Dist., 393 U. S. 503, 506 (1969), the nature of those rights is what is appropriate for children in school. See, e. g., Goss v. Lopez, 419 U. S. 565, 581-582 (1975) (due process for a student challenging disciplinary suspension requires only that the teacher “informally discuss the alleged misconduct with the student minutes after it has occurred”); Fraser, supra, at 683 (“[I]t is a highly appropriate function of public school education to prohibit the use of vulgar and offensive terms in public discourse”); Hazelwood School Dist. v. Kuhlmeier, 484 U. S. 260, 273 (1988) (public school authorities may censor school-sponsored publications, so long as the censorship is “reasonably related to legitimate pedagogical concerns”); Ingraham, supra, at 682 (“Imposing additional administrative safeguards [upon corporal punishment]... would ... entail a significant intrusion into an area of primary educational responsibility”).

Fourth Amendment rights, no less than First and Fourteenth Amendment rights, are different in public schools than elsewhere; the “reasonableness” inquiry cannot disregard the schools’ custodial and tutelary responsibility for children. For their own good and that of their classmates, public school children are routinely required to submit to various physical examinations, and to be vaccinated against various diseases. According to the American Academy of Pediatrics, most public schools “provide vision and hearing screening and dental and dermatological checks. . . . Others also mandate scoliosis screening at appropriate grade levels.” Committee on School Health, American Academy of Pediatrics, School Health: A Guide for Health Professionals 2 (1987). In the 1991-1992 school year, all 50 States required public school students to be vaccinated against diphtheria, measles, rubella, and polio. U. S. Dept, of Health & Human Services, Public Health Service, Centers for Disease Control, State Immunization Requirements 1991-1992, p. 1. Particularly with regard to medical examinations and proce*657dures, therefore, “students within the school environment have a lesser expectation of privacy than members of the population generally.” I L. O., supra, at 348 (Powell, J., concurring).

Legitimate privacy expectations are even less with regard to student athletes. School sports are not for the bashful. They require “suiting up” before each practice or event, and showering and changing afterwards. Public school locker rooms, the usual sites for these activities, are not notable for the privacy they afford. The locker rooms in Vernonia are typical: No individual dressing rooms are provided; shower heads are lined up along a wall, unseparated by any sort of partition or curtain; not even all the toilet stalls have doors. As the United States Court of Appeals for the Seventh Circuit has noted, there is “an element of ‘communal undress’ inherent in athletic participation,” Schaill by Kross v. Tippecanoe County School Corp., 864 F. 2d 1309, 1318 (1988).

There is an additional respect in which school athletes have a reduced expectation of privacy. By choosing to “go out for the team,” they voluntarily subject themselves to a degree of regulation even higher than that imposed on students generally. In Vernonia’s public schools, they must submit to a preseason physical exam (James testified that his included the giving of a urine sample, App. 17), they must acquire adequate insurance coverage or sign an insurance waiver, maintain a minimum grade point average, and comply with any “rules of conduct, dress, training hours and related matters as may be established for each sport by the head coach and athletic director with the principal’s approval.” Record, Exh. 2, p. 30, ¶ 8. Somewhat like adults who choose to participate in a “closely regulated industry,” students who voluntarily participate in school athletics have reason to expect intrusions upon normal rights and privileges, including privacy. See Skinner, 489 U. S., at 627; United States v. Biswell, 406 U. S. 311, 316 (1972).

*658 >

Having considered the scope of the legitimate expectation of privacy at issue here, we turn next to the character of the intrusion that is complained of. We recognized in Skinner that collecting the samples for urinalysis intrudes upon “an excretory function traditionally shielded by great privacy.” 489 U. S., at 626. We noted, however, that the degree of intrusion depends upon the manner in which production of the urine sample is monitored. Ibid. Under the District’s Policy, male students produce samples at a urinal along a wall. They remain fully clothed and are only observed from behind, if at all. Female students produce samples in an enclosed stall, with a female monitor standing outside listening only for sounds of tampering. These conditions are nearly identical to those typically encountered in public restrooms, which men, women, and especially schoolchildren use daily. Under such conditions, the privacy interests compromised by the process of obtaining the urine sample are in our view negligible.

The other privacy-invasive aspect of urinalysis is, of course, the information it discloses concerning the state of the subject’s body, and the materials he has ingested. In this regard it is significant that the tests at issue here look only for drugs, and not for whether the student is, for example, epileptic, pregnant, or diabetic. See id., at 617. Moreover, the drugs for which the samples are screened are standard, and do not vary according to the identity of the student. And finally, the results of the tests are disclosed only to a limited class of school personnel who have a need to know; and they are not turned over to law enforcement authorities or used for any internal disciplinary function. 796 F. Supp., at 1364; see also 23 F. 3d, at 1521.2

*659Respondents argue, however, that the District’s Policy is in fact more intrusive than this suggests, because it requires the students, if they are to avoid sanctions for a falsely positive test, to identify in advance prescription medications they are taking. We agree that this raises some cause for concern. In Von Raab, we flagged as one of the salutary features of the Customs Service drug-testing program the fact that employees were not required to disclose medical information unless they tested positive, and, even then, the information was supplied to a licensed physician rather than to the Government employer. See Von Raab, 489 U. S., at 672-673, n. 2. On the other hand, we have never indicated that requiring advance disclosure of medications is per se unreasonable. Indeed, in Skinner we held that it was not “a significant invasion of privacy.” 489 U. S., at 626, n. 7. It can be argued that, in Skinner, the disclosure went only to the medical personnel taking the sample, and the Government personnel analyzing it, see id., at 609, but see id., at 610 (railroad personnel responsible for forwarding the sample, and presumably accompanying information, to the Government’s testing lab); and that disclosure to teachers and coaches — to persons who personally know the student — is a greater invasion of privacy. Assuming for the sake of argu*660ment that both those propositions are true, we do not believe they establish a difference that respondents are entitled to rely on here.

The General Authorization Form that respondents refused to sign, which refusal was the basis for James’s exclusion from the sports program, said only (in relevant part): “I . . . authorize the Vernonia School District to conduct a test on a urine specimen which I provide to test for drugs and/or alcohol use. I also authorize the release of information concerning the results of such a test to the Vernonia School District and to the parents and/or guardians of the student.” App. 10-11. While the practice of the District seems to have been to have a school official take medication information from the student at the time of the test, see id., at 29, 42, that practice is not set forth in, or required by, the Policy, which says simply: “Student athletes who . . . are or have been taking prescription medication must provide verification (either by a copy of the prescription or by doctor’s authorization) prior to being tested.” Id., at 8. It may well be that, if and when James was selected for random testing at a time that he was taking medication, the School District would have permitted him to provide the requested information in a confidential manner — for example, in a sealed envelope delivered to the testing lab. Nothing in the Policy contradicts that, and when respondents choose, in effect, to challenge the Policy on its face, we will not assume the worst. Accordingly, we reach the same conclusion as in Skinner: that the invasion of privacy was not significant.

V

Finally, we turn to consider the nature and immediacy of the governmental concern at issue here, and the efficacy of this means for meeting it. In both Skinner and Von Raab, we characterized the government interest motivating the search as “compelling.” Skinner, supra, at 628 (interest in preventing railway accidents); Von Raab, supra, at 670 (in*661terest in ensuring fitness of customs officials to interdict drugs and handle firearms). Relying on these cases, the District Court held that because the District’s program also called for drug testing in the absence of individualized suspicion, the District “must demonstrate a ‘compelling need’ for the program.” 796 F. Supp., at 1368. The Court of Appeals appears to have agreed with this view. See 23 F. 3d, at 1526. It is a mistake, however, to think that the phrase “compelling state interest,” in the Fourth Amendment context, describes a fixed, minimum quantum of governmental concern, so that one can dispose of a case by answering in isolation the question: Is there a compelling state interest here? Rather, the phrase describes an interest that appears important enough to justify the particular search at hand, in light of other factors that show the search to be relatively intrusive upon a genuine expectation of privacy. Whether that relatively high degree of government concern is necessary in this case or not, we think it is met.

That the nature of the concern is important — indeed, perhaps compelling — can hardly be doubted. Deterring drug use by our Nation’s schoolchildren is at least as important as enhancing efficient enforcement of the Nation’s laws against the importation of drugs, which was the governmental concern in Von Raab, supra, at 668, or deterring drug use by engineers and trainmen, which was the governmental concern in Skinner, supra, at 628. School years are the time when the physical, psychological, and addictive effects of drugs are most severe. “Maturing nervous systems are more critically impaired by intoxicants than mature ones are; childhood losses in learning are lifelong and profound”; “children grow chemically dependent more quickly than adults, and their record of recovery is depressingly poor.” Hawley, The Bumpy Road to Drug-Free Schools, 72 Phi Delta Kap-pan 310, 314 (1990). See also Estroff, Schwartz, & Hoff-mann, Adolescent Cocaine Abuse: Addictive Potential, Behavioral and Psychiatric Effects, 28 Clinical Pediatrics 550 *662(Dec. 1989); Kandel, Davies, Karus, & Yamaguchi, The Consequences in Young Adulthood of Adolescent Drug Involvement, 43 Arch. Gen. Psychiatry 746 (Aug. 1986). And of course the effects of a drug-infested school are visited not just upon the users, but upon the entire student body and faculty, as the educational process is disrupted. In the present case, moreover, the necessity for the State to act is magnified by the fact that this evil is being visited not just upon individuals at large, but upon children for whom it has undertaken a special responsibility of care and direction. Finally, it must not be lost sight of that this program is directed more narrowly to drug use by school athletes, where the risk of immediate physical harm to the drug user or those with whom he is playing his sport is particularly high. Apart from psychological effects, which include impairment of judgment, slow reaction time, and a lessening of the perception of pain, the particular drugs screened by the District’s Policy have been demonstrated to pose substantial physical risks to athletes. Amphetamines produce an “artificially induced heart rate increase, [peripheral vasoconstriction, [b]lood pressure increase, and [mjasking of the normal fatigue response,” making them a “very dangerous drug when used during exercise of any type.” Hawkins, Drugs and Other Ingesta: Effects on Athletic Performance, in H. Appenzeller, Managing Sports and Risk Management Strategies 90, 90-91 (1993). Marijuana causes “[ijrregular blood pressure responses during changes in body position,” “[Reduction in the oxygen-carrying capacity of the blood,” and “[ijnhibition of the normal sweating responses resulting in increased body temperature.” Id., at 94. Cocaine produces “[vjasocon-striction[,] [e]levated blood pressure,” and “[possible coronary artery spasms and myocardial infarction.” Ibid.

As for the immediacy of the District’s concerns: We are not inclined to question — indeed, we could not possibly find clearly erroneous — the District Court’s conclusion that “a large segment of the student body, particularly those in*663volved in interscholastic athletics, was in a state of rebellion,” that “[disciplinary actions had reached ‘epidemic proportions/” and that “the rebellion was being fueled by alcohol and drug abuse as well as by the student’s mispercep-tions about the drug culture.” 796 F. Supp., at 1357. That is an immediate crisis of greater proportions than existed in Skinner, where we upheld the Government’s drug-testing program based on findings of drug use by railroad employees nationwide, without proof that a problem existed on the particular railroads whose employees were subject to the test. See Skinner, 489 U. S., at 607. And of much greater proportions than existed in Von Raab, where there was no documented history of drug use by any customs officials. See Von Raab, 489 U. S., at 673; id., at 683 (Scalia, J., dissenting).

As to the efficacy of this means for addressing the problem: It seems to us self-evident that a drug problem largely fueled by the “role model” effect of athletes’ drug use, and of particular danger to athletes, is effectively addressed by making sure that athletes do not use drugs. Respondents argue that a “less intrusive means to the same end” was available, namely, “drug testing on suspicion of drug use.” Brief for Respondents 45-46. We have repeatedly refused to declare that only the “least intrusive” search practicable can be reasonable under the Fourth Amendment. Skinner, supra, at 629, n. 9 (collecting cases). Respondents’ alternative entails substantial difficulties — if it is indeed practicable at all. It may be impracticable, for one thing, simply because the parents who are willing to accept random drug testing for athletes are not willing to accept accusatory drug testing for all students, which transforms the process into a badge of shame. Respondents’ proposal brings the risk that teachers will impose testing arbitrarily upon troublesome but not drug-likely students. It generates the expense of defending lawsuits that charge such arbitrary imposition, or that simply demand greater process before accusatory drug

*664testing is imposed. And not least of all, it adds to the ever-expanding diversionary duties of schoolteachers the new function of spotting and bringing to account drug abuse, a task for which they are ill prepared, and which is not readily compatible with their vocation. Cf. Skinner, supra, at 628 (quoting 50 Fed. Reg. 31526 (1985)) (a drug impaired individual “will seldom display any outward ‘signs detectable by the lay person or, in many cases, even the physician’”); Goss, 419 U. S., at 594 (Powell, J., dissenting) (“There is an ongoing relationship, one in which the teacher must occupy many roles — educator, adviser, friend, and, at times, parent-substitute. It is rarely adversary in nature . . .”) (footnote omitted). In many respects, we think, testing based on “suspicion” of drug use would not be better, but worse.3

>

Taking into account all the factors we have considered above — the decreased expectation of privacy, the relative unobtrusiveness of the search, and the severity of the need met *665by the search — we conclude Vernonia’s Policy is reasonable and hence constitutional.

We caution against the assumption that suspicionless drug testing will readily pass constitutional muster in other contexts. The most significant element in this case is the first we discussed: that the Policy was undertaken in furtherance of the government’s responsibilities, under a public school system, as guardian and tutor of children entrusted to its care.4 Just as when the government conducts a search in its capacity as employer (a warrantless search of an absent employee’s desk to obtain an urgently needed file, for example), the relevant question is whether that intrusion upon privacy is one that a reasonable employer might engage in, see O’Connor v. Ortega, 480 U. S. 709 (1987); so also when the government acts as guardian and tutor the relevant question is whether the search is one that a reasonable guardian and tutor might undertake. Given the findings of need made by the District Court, we conclude that in the present case it is.

We may note that the primary guardians of Vernonia’s schoolchildren appear to agree. The record shows no objection to this districtwide program by any parents other than the couple before us here — even though, as we have described, a public meeting was held to obtain parents’ views. We find insufficient basis to contradict the judgment of Ver-nonia’s parents, its school board, and the District Court, as to what was reasonably in the interest of these children under the circumstances.

*666* * *

The Ninth Circuit held that Vernonia’s Policy not only violated the Fourth Amendment, but also, by reason of that violation, contravened Article I, § 9, of the Oregon Constitution. Our conclusion that the former holding was in error means that the latter holding rested on a flawed premise. We therefore vacate the judgment, and remand the case to the Court of Appeals for further proceedings consistent with this opinion.

It is so ordered.

Justice Ginsburg,

concurring.

The Court constantly observes that the School District’s drug-testing policy applies only to students who voluntarily participate in interscholastic athletics. Ante, at 650,657 (reduced privacy expectation and closer school regulation of student athletes), 662 (drug use by athletes risks immediate physical harm to users and those with whom they play). Correspondingly, the most severe sanction allowed under the District’s policy is suspension from extracurricular athletic programs. Ante, at 651. I comprehend the Court’s opinion as reserving the question whether the District, on no more than the showing made here, constitutionally could impose routine drug testing not only on those seeking to engage with others in team sports, but on all students required to attend school. Cf. United States v. Edwards, 498 F. 2d 496, 500 (CA2 1974) (Friendly, J.) (in contrast to search without notice and opportunity to avoid examination, airport search of passengers and luggage is avoidable “by choosing not to travel by air”) (internal quotation marks omitted).

Justice O’Connor,

with whom Justice Stevens and Justice Souter join,

dissenting.

The population of our Nation’s public schools, grades 7 through 12, numbers around 18 million. See U. S. Dept, of *667Education, National Center for Education Statistics, Digest of Education Statistics 58 (1994) (Table 43). By the reasoning of today’s decision, the millions of these students who participate in interscholastic sports, an overwhelming majority of whom have given school officials no reason whatsoever to suspect they use drugs at school, are open to an intrusive bodily search.

In justifying this result, the Court dispenses with a requirement of individualized suspicion on considered policy grounds. First, it explains that precisely because every student athlete is being tested, there is no concern that school officials might act arbitrarily in choosing whom to test. Second, a broad-based search regime, the Court reasons, dilutes the accusatory nature of the search. In making these policy arguments, of course, the Court sidesteps powerful, countervailing privacy concerns. Blanket searches, because they can involve “thousands or millions” of searches, “pos[e] a greater threat to liberty” than do suspicion-based ones, which “affec[t] one person at a time,” Illinois v. Krull, 480 U. S. 340, 365 (1987) (O’Connor, J., dissenting). Searches based on individualized suspicion also afford potential targets considerable control over whether they will, in fact, be searched because a person can avoid such a search by not acting in an objectively suspicious way. And given that the surest way to avoid acting suspiciously is to avoid the underlying wrongdoing, the costs of such a regime, one would think, are minimal.

But whether a blanket search is “better,” ante, at 664, than a regime based on individualized suspicion is not a debate in which we should engage. In my view, it is not open to judges or government officials to decide on policy grounds which is better and which is worse. For most of our constitutional history, mass, suspicionless searches have been generally considered per se unreasonable within the meaning of the Fourth Amendment. And we have allowed exceptions *668in recent years only where it has been clear that a suspicion-based regime would be ineffectual. Because that is not the case here, I dissent.

I

A

In Carroll v. United States, 267 U. S. 132 (1925), the Court explained that “[t]he Fourth Amendment does not denounce all searches or seizures, but only such as are unreasonable.” Id., at 147. Applying this standard, the Court first held that a search of a car was not unreasonable merely because it was warrantless; because obtaining a warrant is impractical for an easily movable object such as a car, the Court explained, a warrant is not required. The Court also held, however, that a warrantless car search was unreasonable unless supported by some level of individualized suspicion, namely, probable cause. Significantly, the Court did not base its conclusion on the express probable cause requirement contained in the Warrant Clause, which, as just noted, the Court found inapplicable. Rather, the Court rested its views on “what was deemed an unreasonable search and seizure when [the Fourth Amendment] was adopted” and “[what] will conserve public interests as well as the interests and rights of individual citizens.” Id., at 149. With respect to the “rights of individual citizens,” the Court eventually offered the simple yet powerful intuition that “those lawfully within the country, entitled to use the public highways, have a right to free passage without interruption or search unless there is known to a competent official authorized to search, probable cause for believing that their vehicles are carrying contraband or illegal merchandise.” Id., at 154.

More important for the purposes of this case, the Court clearly indicated that evenhanded treatment was no substitute for the individualized suspicion requirement:

“It would be intolerable and unreasonable if a prohibition agent were authorized to stop every automobile on *669the chance of finding liquor and thus subject all persons lawfully using the highways to the inconvenience and indignity of such a search.” Id., at 153-154.

The Carroll Court’s view that blanket searches are “intolerable and unreasonable” is well grounded in history. As recently confirmed in one of the most exhaustive analyses of the original meaning of the Fourth Amendment ever undertaken, see W. Cuddihy, The Fourth Amendment: Origins and Original Meaning (1990) (Ph.D. Dissertation at Claremont Graduate School) (hereinafter Cuddihy), what the Framers of the Fourth Amendment most strongly opposed, with limited exceptions wholly inapplicable here, were general searches — that is, searches by general warrant, by writ of assistance, by broad statute, or by any other similar authority. See id., at 1402, 1499, 1555; see also Clancy, The Role of Individualized Suspicion in Assessing the Reasonableness of Searches and Seizures, 25 Mem. St. U. L. Rev. 483, 528 (1994); Maclin, When the Cure for the Fourth Amendment Is Worse Than the Disease, 68 S. Cal. L. Rev. 1, 9-12 (1994); L. Levy, Original Intent and the Framers’ Constitution 221-246 (1988). Although, ironically, such warrants, writs, and statutes typically required individualized suspicion, see, e.g., Cuddihy 1140 (“Typical of the American warrants of 1761-76 was Starke’s ‘tobacco’ warrant, which commanded its bearer to ‘enter any suspected Houses’ ”) (emphasis added), such requirements were subjective and largely unenforceable. Accordingly, these various forms of authority led in practice to “virtually unrestrained,” and hence “general,” searches. J. Landynski, Search and Seizure and the Supreme Court 20 (1966). To be sure, the Fourth Amendment, in the Warrant Clause, prohibits by name only searches by general warrants. But that was only because the abuses of the general warrant were particularly vivid in the minds of the Framers’ generation, Cuddihy 1554-1560, and not because the Framers viewed other kinds of general searches as any less unreasonable. “Prohibition of the general warrant was part of a *670larger scheme to extinguish general searches categorically.” Id., at 1499.

More important, there is no indication in the historical materials that the Framers’ opposition to general searches stemmed solely from the fact that they allowed officials to single out individuals for arbitrary reasons, and thus that officials could render them reasonable simply by making sure to extend their search to every house in a given area or to every person in a given group. See Delaware v. Prouse, 440 U. S. 648, 664 (1979) (Rehnquist, J., dissenting) (referring to this as the “ ‘misery loves company’ ” theory of the Fourth Amendment). On the contrary, although general searches were typically arbitrary, they were not invariably so. Some general searches, for example, were of the arguably evenhanded “door-to-door” kind. Cuddihy 1091; see also id., at 377, 1502, 1557. Indeed, Cuddihy’s descriptions of a few blanket searches suggest they may have been considered more worrisome than the typical general search. See id., at 575 (“One type of warrant [between 1700 and 1760] went beyond a general search, in which the searcher entered and inspected suspicious places, by requiring him to search entire categories of places whether he suspected them or not”); id., at 478 (“During the exigencies of Queen Anne’s War, two colonies even authorized searches in 1706 that extended to entire geographic areas, not just to suspicious houses in a district, as conventional general warrants allowéd”).

Perhaps most telling of all, as reflected in the text of the Warrant Clause, the particular way the Framers chose to curb the abuses of general warrants — and by implication, all general searches — was not to impose a novel “evenhandedness” requirement; it was to retain the individualized suspicion requirement contained in the typical general warrant, but to make that requirement meaningful and enforceable, for instance, by raising the required level of individualized suspicion to objective probable cause. See U. S. Const., Arndt. 4. So, for example, when the same Congress that *671proposed the Fourth Amendment authorized duty collectors to search for concealed goods subject to import duties, specific warrants were required for searches on land; but even for searches at sea, where warrants were impractical and thus not required, Congress nonetheless limited officials to searching only those ships and vessels “in which [a collector] shall have reason to suspect any goods, wares or merchandise subject to duty shall be concealed.” The Collection Act of July 31, 1789, § 24, 1 Stat. 43 (emphasis added); see also Cuddihy 1490-1491 (“The Collection Act of 1789 was [the] most significant [of all early search statutes], for it identified the techniques of search and seizure that the framers of the amendment believed reasonable while they were framing it”). Not surprisingly, the Carroll Court relied on this statute and other subsequent ones like it in arriving at its views. See Carroll, 267 U. S., at 160-151, 154; cf. Clancy, supra, at 489 (“While the plain language of the Amendment does not mandate individualized suspicion as a necessary component of all searches and seizures, the historical record demonstrates that the framers believed that individualized suspicion was an inherent quality of reasonable searches and seizures”).

True, not all searches around the time the Fourth Amendment was adopted required individualized suspicion — although most did. A search incident to arrest was an obvious example of one that did not, see Cuddihy 1518, but even those searches shared the essential characteristics that distinguish suspicion-based searches from abusive general searches: they only “affec[t] one person at a time,” Krull, 480 U. S., at 365 (O’Connor, J., dissenting), and they are generally avoidable by refraining from wrongdoing. See supra, at 667. Protection of privacy, not evenhandedness, was then and is now the touchstone of the Fourth Amendment.

The view that mass, suspicionless searches, however evenhanded, are generally unreasonable remains inviolate in the criminal law enforcement context, see Ybarra v. Illinois, 444 *672U. S. 85 (1979) (invalidating evenhanded, nonaccusatory pat-down for weapons of all patrons in a tavern in which there was probable cause to think drug dealing was going on), at least where the search is more than minimally intrusive, see Michigan Dept. of State Police v. Sitz, 496 U. S. 444 (1990) (upholding the brief and easily avoidable detention, for purposes of observing signs of intoxication, of all motorists approaching a roadblock). It is worth noting in this regard that state-compelled, state-monitored collection and testing of urine, while perhaps not the most intrusive of searches, see, e. g., Bell v. Wolfish, 441 U. S. 520, 558-560 (1979) (visual body cavity searches), is still “particularly destructive of privacy and offensive to personal dignity.” Treasury Employees v. Von Raab, 489 U. S. 656, 680 (1989) (Scalia, J., dissenting); see also ante, at 658; Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 617 (1989). We have not hesitated to treat monitored bowel movements as highly intrusive (even in the special border search context), compare United States v. Martinez-Fuerte, 428 U. S. 543 (1976) (brief interrogative stops of all motorists crossing certain border checkpoint reasonable without individualized suspicion), with United States v. Montoya de Hernandez, 473 U. S. 531 (1985) (monitored bowel movement of border crossers reasonable only upon reasonable suspicion of alimentary canal smuggling), and it is not easy to draw a distinction. See Fried, Privacy, 77 Yale L. J. 475, 487 (1968) (“[I]n our culture the excretory functions are shielded by more or less absolute privacy”). And certainly monitored urination combined with urine testing is more intrusive than some personal searches we have said trigger Fourth Amendment protections in the past. See, e. g., Cupp v. Murphy, 412 U. S. 291, 295 (1973) (Stewart, J.) (characterizing the scraping of dirt from under a person’s fingernails as a “ ‘severe, though brief, intrusion upon cherished personal security’ ”) (citation omitted). Finally, the collection and testing of urine is, of course, a search of a person, one of only four categories of suspect *673searches the Constitution mentions by name. See U. S. Const., Arndt. 4 (listing “persons, houses, papers, and effects”); cf. Cuddihy 835, 1518, 1552, n. 394 (indicating long history of outrage at personal searches before 1789).

Thus, it remains the law that the police cannot, say, subject to drug testing every person entering or leaving a certain drug-ridden neighborhood in order to find evidence of crime. 3 W. LaFave, Search and Seizure § 9.5(b), pp. 551-553 (2d ed. 1987) (hereinafter LaFave). And this is true even though it is hard to think of a more compelling government interest than the need to fight the scourge of drugs on our streets and in our neighborhoods. Nor could it be otherwise, for if being evenhanded were enough to justify evaluating a search regime under an open-ended balancing test, the Warrant Clause, which presupposes that there is some category of searches for which individualized suspicion is nonnegotiable, see 2 LaFave §4.1, at 118, would be a dead letter.

Outside the criminal context, however, in response to the exigencies of modern life, our cases have upheld several evenhanded blanket searches, including some that are more than minimally intrusive, after balancing the invasion of privacy against the government’s strong need. Most of these cases, of course, are distinguishable insofar as they involved searches either not of a personally intrusive nature, such as searches of closely regulated businesses, see, e. g., New York v. Burger, 482 U. S. 691, 699-703 (1987); cf. Cuddihy 1501 (“Even the states with the strongest constitutional restrictions on general searches had long exposed commercial establishments to warrantless inspection”), or arising in unique contexts such as prisons, see, e. g., Wolfish, supra, at 558-560 (visual body cavity searches of prisoners following contact visits); cf. Cuddihy 1516-1519, 1552-1553 (indicating that searches incident to arrest and prisoner searches were the only common personal searches at time of founding). This certainly explains why Justice Scalia, in his dissent in our recent Von Raab decision, found it significant that “[u]ntil *674today this Court had upheld a bodily search separate from arrest and without individualized suspicion of wrongdoing only with respect to prison inmates, relying upon the uniquely dangerous nature of that environment.” Von Raab, supra, at 680 (citation omitted).

In any event, in many of the cases that can be distinguished on the grounds suggested above and, more important, in all of the cases that cannot, see, e. g., Skinner, supra (blanket drug testing scheme); Von Raab, supra (same); cf. Camara v. Municipal Court of City and County of San Francisco, 387 U. S. 523 (1967) (area-wide searches of private residences), we upheld the suspicionless search only after first recognizing the Fourth Amendment’s longstanding preference for a suspicion-based search regime, and then pointing to sound reasons why such a regime would likely be ineffectual under the unusual circumstances presented. In Skinner, for example, we stated outright that “ ‘some quantum of individualized suspicion’ ” is “usually required” under the Fourth Amendment, Skinner, supra, at 624, quoting Martinez-Fuerte, supra, at 560, and we built the requirement into the test we announced: “In limited circumstances, where the privacy interests implicated by the search are minimal, and where an important governmental interest furthered by the intrusion would be placed in jeopardy by a requirement of individualized suspicion, a search may be reasonable despite the absence of such suspicion,” 489 U. S., at 624 (emphasis added). The obvious negative implication of this reasoning is that, if such an individualized suspicion requirement would not place the government’s objectives in jeopardy, the requirement should not be forsaken. See also Von Raab, supra, at 665-666.

Accordingly, we upheld the suspicionless regime at issue in Skinner on the firm understanding that a requirement of individualized suspicion for testing train operators for drug or alcohol impairment following serious train accidents would be unworkable because “the scene of a serious rail *675accident is chaotic.” Skinner, 489 U. S., at 631. (Of course, it could be plausibly argued that the fact that testing occurred only after train operators were involved in serious train accidents amounted to an individualized suspicion requirement in all but name, in light of the record evidence of a strong link between serious train accidents and drug and alcohol use.) We have performed a similar inquiry in the other cases as well. See Von Raab, 489 U. S., at 674 (suspicion requirement for searches of customs officials for drug impairment impractical because “not feasible to subject [such] employees and their work product to the kind of day-to-day scrutiny that is the norm in more traditional office environments”); Camara, supra, at 537 (suspicion requirement for searches of homes for safety code violations impractical because conditions such as “faulty wiring” not observable from outside of house); see also Wolfish, 441 U. S., at 559-560, n. 40 (suspicion requirement for searches of prisoners for smuggling following contact visits impractical because observation necessary to gain suspicion would cause “obvious disruption of the confidentiality and intimacy that these visits are intended to afford”); Martinez-Fuerte, 428 U. S., at 557 (“A requirement that stops on major routes inland always be based on reasonable suspicion would be impractical because the flow of traffic tends to be too heavy to allow the particularized study of a given car that would enable it to be identified as a possible carrier of illegal aliens”); United States v. Edwards, 498 F. 2d 496, 500 (CA2 1974) (Friendly, J.) (suspicion-based searches of airport passengers’ carry-on luggage impractical because of the great number of plane travelers and “conceded inapplicability” of the profile method of detecting hijackers).

Moreover, an individualized suspicion requirement was often impractical in these cases because they involved situations in which even one undetected instance of wrongdoing could have injurious consequences for a great number of people. See, e. g., Camara, supra, at 535 (even one safety code *676violation can cause “fires and epidemics [that] ravage large urban areas”); Skinner, supra, at 628 (even one drug- or alcohol-impaired train operator can lead to the “disastrous consequences” of a train wreck, such as “great human loss”); Von Raab, supra, at 670, 674, 677 (even one customs official caught up in drugs can, by virtue of impairment, susceptibility to bribes, or indifference, result in the noninterdiction of a “sizable drug shipmen[t],” which eventually injures the lives of thousands, or to a breach of “national security”); Edwards, supra, at 600 (even one hijacked airplane can destroy “ ‘hundreds of human lives and millions of dollars of property’ ”) (citation omitted).

B

The instant case stands in marked contrast. One searches today’s majority opinion in vain for recognition that history and precedent establish that individualized suspicion is “usually required” under the Fourth Amendment (regardless of whether a warrant and probable cause are also required) and that, in the area of intrusive personal searches, the only recognized exception is for situations in which a suspicion-based scheme would be likely ineffectual. See supra, at 674-675 and this page. Far from acknowledging anything special about individualized suspicion, the Court treats a suspicion-based regime as if it were just any run-of-the-mill, less intrusive alternative — that is, an alternative that officials may bypass if the lesser intrusion, in their reasonable estimation, is outweighed by policy concerns unrelated to practicability.

As an initial matter, I have serious doubts whether the Court is right that the District reasonably found that the lesser intrusion of a suspicion-based testing program outweighed its genuine concerns for the adversarial nature of such a program, and for its abuses. See ante, at 663-664. For one thing, there are significant safeguards against abuses. The fear that a suspicion-based regime will lead to the testing of “troublesome but not drug-likely” students, *677ante, at 663, for example, ignores that the required level of suspicion in the school context is objectively reasonable suspicion. In this respect, the facts of our decision in New Jersey v. I L. O., 469 U. S. 325 (1985), should be reassuring. There, we found reasonable suspicion to search a ninth-grade girl’s purse for cigarettes after a teacher caught the girl smoking in the bathroom with a companion who admitted it. See id., at 328, 345-346. Moreover, any distress arising from what turns out to be a false accusation can be minimized by keeping the entire process confidential.

For another thing, the District’s concern for the adversarial nature of a suspicion-based regime (which appears to extend even to those who are rightly accused) seems to ignore the fact that such a regime would not exist in a vacuum. Schools already have adversarial, disciplinary schemes that require teachers and administrators in many areas besides drug use to investigate student wrongdoing (often by means of accusatory searches); to make determinations about whether the wrongdoing occurred; and to impose punishment. To such a scheme, suspicion-based drug testing would be only a minor addition. The District’s own elaborate disciplinary scheme is reflected in its handbook, which, among other things, lists the following disciplinary “problem areas” carrying serious sanctions: “DEFIANCE OF AUTHORITY,” “DISORDERLY OR DISRUPTIVE CONDUCT INCLUDING FOUL LANGUAGE,” “AUTOMOBILE USE OR MISUSE,” “FORGERY OR LYING,” “GAMBLING,” “THEFT,” “TOBACCO,” “MISCHIEF,” “VANDALISM,” “RECKLESSLY ENDANGERING,” “MENACING OR HARASSMENT,” “ASSAULT,” “FIGHTING,” “WEAPONS,” “EXTORTION,” “EXPLOSIVE DEVICES,” and “ARSON.” Record, Exh. 2, p. 11; see also id., at 20-21 (listing rules regulating dress and grooming, public displays of affection, and the wearing of hats inside); cf. id., at 8 (“RESPONSIBILITIES OF SCHOOLS” include “To develop and distribute to parents and students reasonable rules *678and regulations governing student behavior and attendance” and “To provide fair and reasonable standards of conduct and to enforce those standards through appropriate disciplinary action”). The high number of disciplinary referrals in the record in this case illustrates the District’s robust scheme in action.

In addition to overstating its concerns with a suspicion-based program, the District seems to have understated the extent to which such a program is less intrusive of students’ privacy. By invading the privacy of a few students rather than many (nationwide, of thousands rather than millions), and by giving potential search targets substantial control over whether they will, in fact, be searched, a suspicion-based scheme is significantly less intrusive.

In any event, whether the Court is right that the District reasonably weighed the lesser intrusion of a suspicion-based scheme against its policy concerns is beside the point. As stated, a suspicion-based search regime is not just any less intrusive alternative; the individualized suspicion requirement has a legal pedigree as old as the Fourth Amendment itself, and it may not be easily cast aside in the name of policy concerns. It may only be forsaken, our cases in the personal search context have established, if a suspicion-based regime would likely be ineffectual.

But having misconstrued the fundamental role of the individualized suspicion requirement in Fourth Amendment analysis, the Court never seriously engages the practicality of such a requirement in the instant case. And that failure is crucial because nowhere is it less clear that an individualized suspicion requirement would be ineffectual than in the school context. In most schools, the entire pool of potential search targets — students—is under constant supervision by teachers and administrators and coaches, be it in classrooms, hallways, or locker rooms. See T. L. O., 469 U. S., at 339 (“[A] proper educational environment requires close supervision of schoolchildren”).

*679The record here indicates that the Vernonia schools are no exception. The great irony of this case is that most (though not all) of the evidence the District introduced to justify its suspicionless drug testing program consisted of first- or second-hand stories of particular, identifiable students acting in ways that plainly gave rise to reasonable suspicion of in-school drug use — and thus that would have justified a drug-related search under our T. L. O. decision. See id., at 340-342 (warrant and probable cause not required for school searches; reasonable suspicion sufficient). Small groups of students, for example, were observed by a teacher “passing joints back and forth” across the street at a restaurant before school and during school hours. Tr. 67 (Apr. 29,1992). Another group was caught skipping school and using drugs at one of the students’ houses. See id., at 93-94. Several students actually admitted their drug use to school officials (some of them being caught with marijuana pipes). See id., at 24. One student presented himself to his teacher as “clearly obviously inebriated” and had to be sent home. Jd., at 68. Still another was observed dancing and singing at the top of his voice in the back of the classroom; when the teacher asked what was going on, he replied, “Well, I’m just high on life.” Id., at 89-90. To take a final example, on a certain road trip, the school wrestling coach smelled marijuana smoke in a motel room occupied by four wrestlers, see id., at 110-112, an observation that (after some questioning) would probably have given him reasonable suspicion to test one or all of them. Cf. 4 LaFave § 10.11(b), at 169 (“[I]n most instances the evidence of wrongdoing prompting teachers or principals to conduct searches is sufficiently detailed and specific to meet the traditional probable cause test”).

In light of all this evidence of drug use by particular students, there is a substantial basis for concluding that a vigorous regime of suspicion-based testing (for which the District appears already to have rules in place, see Record, Exh. 2, at 14, 17) would have gone a long way toward solving Ver-*680nonia’s school drug problem while preserving the Fourth Amendment rights of James Acton and others like him. And were there any doubt about such a conclusion, it is removed by indications in the record that suspicion-based testing could have been supplemented by an equally vigorous campaign to have Vernonia’s parents encourage their children to submit to the District’s voluntary drug testing program. See id., at 32 (describing the voluntary program); ante, at 665 (noting widespread parental support for drug testing). In these circumstances, the Fourth Amendment dictates that a mass, suspicionless search regime is categorically unreasonable.

I recognize that a suspicion-based scheme, even where reasonably effective in controlling in-school drug use, may not be as effective as a mass, suspicionless testing regime. In one sense, that is obviously true — -just as it is obviously true that suspicion-based law enforcement is not as effective as mass, suspicionless enforcement might be. “But there is nothing new in the realization” that Fourth Amendment protections come with a price. Arizona v. Hicks, 480 U. S. 321, 329 (1987). Indeed, the price we pay is higher in the criminal context, given that police do not closely observe the entire class of potential search targets (all citizens in the area) and must ordinarily adhere to the rigid requirements of a warrant and probable cause.

The principal counterargument to all this, central to the Court’s opinion, is that the Fourth Amendment is more lenient with respect to school searches. That is no doubt correct, for, as the Court explains, ante, at 655-656, schools have traditionally had special guardianlike responsibilities for children that necessitate a degree of constitutional leeway. This principle explains the considerable Fourth Amendment leeway we gave school officials in I L. O. In that case, we held that children at school do not enjoy two of the Fourth Amendment's traditional categorical protections against unreasonable searches and seizures: the warrant requirement *681and the probable cause requirement. See T L. O., 469 U. S., at 337-343. And this was true even though the same children enjoy such protections “in a nonschool setting.” Id., at 348 (Powell, J., concurring).

The instant case, however, asks whether the Fourth Amendment is even more lenient than that, i. e., whether it is so lenient that students may be deprived of the Fourth Amendment’s only remaining, and most basic, categorical protection: its strong preference for an individualized suspicion requirement, with its accompanying antipathy toward personally intrusive, blanket searches of mostly innocent people. It is not at all clear that people in prison lack this categorical protection, see Wolfish, 441 U. S., at 558-560 (upholding certain suspicionless searches of prison inmates); but cf. supra, at 675 (indicating why suspicion requirement was impractical in Wolfisk), and we have said “[w]e are not yet ready to hold that the schools and the prisons need be equated for purposes of the Fourth Amendment.” T L. O., supra, at 338-339. Thus, if we are to mean what we often proclaim — that students do not “shed their constitutional rights ... at the schoolhouse gate,” Tinker v. Des Moines Independent Community School Dist., 393 U. S. 503, 506 (1969) — the answer must plainly be no.1

*682For the contrary position, the Court relies on cases such as T L. O., Ingraham v. Wright, 430 U. S. 651 (1977), and Goss v. Lopez, 419 U. S. 565 (1975). See ante, at 655-656. But I find the Court’s reliance on these cases ironic. If anything, they affirm that schools have substantial constitutional leeway in carrying out their traditional mission of responding to particularized wrongdoing. See T. L. O., supra (leeway in investigating particularized wrongdoing); Ingraham, supra (leeway in punishing particularized wrongdoing); Goss, supra (leeway in choosing procedures by which particularized wrongdoing is punished).

By contrast, intrusive, blanket searches of schoolchildren, most of whom are innocent, for evidence of serious wrongdoing are not part of any traditional school function of which I am aware. Indeed, many schools, like many parents, prefer to trust their children unless given reason to do otherwise. As James Acton’s father said on the witness stand, “[suspi-cionless testing] sends a message to children that are trying to be responsible citizens . . . that they have to prove that they’re innocent..., and I think that kind of sets a bad tone for citizenship.” Tr. 9 (Apr. 29, 1992).

I find unpersuasive the Court’s reliance, ante, at 656-657, on the widespread practice of physical examinations and vaccinations, which are both blanket searches of a sort. Of course, for these practices to have any Fourth Amendment significance, the Court has to assume that these physical exams and vaccinations are typically “required” to a similar extent that urine testing and collection is required in the instant case, i. e., that they are required regardless of parental *683objection and that some meaningful sanction attaches to the failure to submit. In any event, without forming any particular view of such searches, it is worth noting that a suspicion requirement for vaccinations is not merely impractical; it is nonsensical, for vaccinations are not searches for anything in particular and so there is nothing about which to be suspicious. Nor is this saying anything new; it is the same theory on which, in part, we have repeatedly upheld certain inventory searches. See, e. g., South Dakota v. Opperman, 428 U. S. 364, 370, n. 5 (1976) (“The probable-cause approach is unhelpful when analysis centers upon the reasonableness of routine administrative caretaking functions”). As for physical examinations, the practicability of a suspicion requirement is highly doubtful because the conditions for which these physical exams ordinarily search, such as latent heart conditions, do not manifest themselves in observable behavior the way school drug use does. See supra, at 679-680.

It might also be noted that physical exams (and of course vaccinations) are not searches for conditions that reflect wrongdoing on the part of the student, and so are wholly nonaccusatory and have no consequences that can be regarded as punitive. These facts may explain the absence of Fourth Amendment challenges to such searches. By contrast, although I agree with the Court that the accusatory nature of the District’s testing program is diluted by making it a blanket one, any testing program that searches for conditions plainly reflecting serious wrongdoing can never be made wholly nonaccusatory from the student’s perspective, the motives for the program notwithstanding; and for the same reason, the substantial consequences that can flow from a positive test, such as suspension from sports, are invariably — and quite reasonably — understood as punishment. The best proof that the District’s testing program is to some extent accusatory can be found in James Acton’s own explanation on the witness stand as to why he did not want to submit to drug testing: “Because I feel that they have no *684reason to think I was taking drugs.” Tr. 13 (Apr. 29, 1992). It is hard to think of a manner of explanation that resonates more intensely in our Fourth Amendment tradition than this.

II

I do not believe that suspicionless drug testing is justified on these facts. But even if I agreed that some such testing were reasonable here, I see two other Fourth Amendment flaws in the District’s program.2 First, and most serious, there is virtually no evidence in the record of a drug problem at the Washington Grade School, which includes the seventh and eighth grades, and which Acton attended when this litigation began. This is not surprising, given that, of the four witnesses who testified to drug-related incidents, three were teachers and/or coaches at the high school, see Tr. 65; id., at 86; id., at 99, and the fourth, though the principal of the grade school at the time of the litigation, had been employed as principal of the high school during the years leading up to (and beyond) the implementation of the drug testing policy. See id., at 17. The only evidence of a grade school drug problem that my review of the record uncovered is a “guarantee” by the late-arriving grade school principal that “our problems we’ve had in ’88 and ’89 didn’t start at the high school level. They started in the elementary school.” Id., at 43. But I would hope that a single assertion of this sort would not serve as an adequate basis on which to uphold mass, suspicionless drug testing of two entire grades of student athletes — in Vernonia and, by the Court’s reasoning, in other school districts as well. Perhaps there is a drug problem at the grade school, but one would not know it from this *685record. At the least, then, I would insist that the parties and the District Court address this issue on remand.

Second, even as to the high school, I find unreasonable the school’s choice of student athletes as the class to subject to suspicionless testing — a choice that appears to have been driven more by a belief in what would pass constitutional muster, see id., at 45-47 (indicating that the original program was targeted at students involved in any extracurricular activity), than by a belief in what was required to meet the District’s principal disciplinary concern. Reading the full record in this case, as well as the District Court’s authoritative summary of it, 796 F. Supp. 1354, 1356-1357 (Ore. 1992), it seems quite obvious that the true driving force behind the District’s adoption of its drug testing program was the need to combat the rise in drug-related disorder and disruption in its classrooms and around campus. I mean no criticism of the strength of that interest. On the contrary, where the record demonstrates the existence of such a problem, that interest seems self-evidently compelling. “Without first establishing discipline and maintaining order, teachers cannot begin to educate their students.” I L. O., 469 U. S., at 350 (Powell, J., concurring). And the record in this case surely demonstrates there was a drug-related discipline problem in Vernonia of “‘epidemic proportions.’” 796 F. Supp., at 1357. The evidence of a drug-related sports injury problem at Vernonia, by contrast, was considerably weaker.

On this record, then, it seems to me that the far more reasonable choice would have been to focus on the class of students found to have violated published school rules against severe disruption in class and around campus, see Record, Exh. 2, at 9,11 — disruption that had a strong nexus to drug use, as the District established at trial. Such a choice would share two of the virtues of a suspicion-based regime: testing dramatically fewer students, tens as against hundreds, and giving students control, through their behav*686ior, over the likelihood that they would be tested. Moreover, there would be a reduced concern for the accusatory nature of the search, because the Court’s feared “badge of shame,” ante, at 663, would already exist, due to the antecedent accusation and finding of severe disruption. In a lesser known aspect of Skinner, we upheld an analogous testing scheme with little hesitation. See Skinner, 489 U. S., at 611 (describing “ ‘Authorization to Test for Cause’ ” scheme, according to which train operators would be tested “in the event of certain specific rule violations, including noncompliance with a signal and excessive speeding”).

III

It cannot be too often stated that the greatest threats to our constitutional freedoms come in times of crisis. But we must also stay mindful that not all government responses to such times are hysterical overreactions; some crises are quite real, and when they are, they serve precisely as the compelling state interest that we have said may justify a measured intrusion on constitutional rights. The only way for judges to mediate these conflicting impulses is to do what they should do anyway: stay close to the record in each case that appears before them, and make their judgments based on that alone. Having reviewed the record here, I cannot avoid the conclusion that the District’s suspicionless policy of testing all student athletes sweeps too broadly, and too imprecisely, to be reasonable under the Fourth Amendment.

Justice Thomas

delivered the opinion of the Court.

The Student Activities Drug Testing Policy implemented by the Board of Education of Independent School District No. 92 of Pottawatomie County (School District) requires all students who participate in competitive extracurricular activities to submit to drug testing. Because this Policy reasonably serves the School District’s important interest in detecting and preventing drug use among its students, we hold that it is constitutional.

*826HH

The city of Tecumseh, Oklahoma, is a rural community located approximately 40 miles southeast of Oklahoma City. The School District administers all Tecumseh public schools. In the fall of 1998, the School District adopted the Student Activities Drug Testing Policy (Policy), which requires all middle and high school students to consent to drug testing in order to participate in any extracurricular activity. In practice, the Policy has been applied only to competitive extracurricular activities sanctioned by the Oklahoma Secondary Schools Activities Association, such as the Academic Team, Future Farmers of America, Future Homemakers of America, band, choir, pom pon, cheerleading, and athletics. Under the Policy, students are required to take a drug test before participating in an extracurricular activity, must submit to random drug testing while participating in that activity, and must agree to be tested at any time upon reasonable suspicion. The urinalysis tests are designed to detect only the use of illegal drugs, including amphetamines, marijuana, cocaine, opiates, and barbituates, not medical conditions or the presence of authorized prescription medications.

At the time of their suit, both respondents attended Tecumseh High School. Respondent Lindsay Earls was a member of the show choir, the marching band, the Academic Team, and the National Honor Society. Respondent Daniel James sought to participate in the Academic Team.1 Together with their parents, Earls and James brought a Rev. *827Stat. § 1979, 42 U. S. C. § 1983, action against the School District, challenging the Policy both on its face and as applied to their participation in extracurricular activities.2 They alleged that the Policy violates the Fourth Amendment as incorporated by the Fourteenth Amendment and requested in-junctive and declarative relief. They also argued that the School District failed to identify a special need for testing students who participate in extracurricular activities, and that the “Drug Testing Policy neither addresses a proven problem nor promises to bring any benefit to students or the school.” App. 9.

Applying the principles articulated in Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), in which we upheld the suspicionless drug testing of school athletes, the United States District Court for the Western District of Oklahoma rejected respondents’ claim that the Policy was unconstitutional and granted summary judgment to the School District. The court noted that “special needs” exist in the public school context and that, although the School District did “not show a drug problem of epidemic proportions,” there was a history of drug abuse starting in 1970 that presented “legitimate cause for concern.” 115 F. Supp. 2d 1281, 1287 (2000). The District Court also held that the Policy was effective because “[i]t can scarcely be disputed that the drug problem among the student body is effectively addressed by making sure that the large number of students participating in competitive, extracurricular activities do not use drugs.” Id., at 1295.

The United States Court of Appeals for the Tenth Circuit reversed, holding that the Policy violated the Fourth Amendment. The Court of Appeals agreed with the District Court that the Policy must be evaluated in the “unique environment of the school setting,” but reached a different conclu*828sion as to the Policy’s constitutionality. 242 F. 3d 1264, 1270 (2001). Before imposing a suspicionless drug testing program, the Court of Appeals concluded that a school “must demonstrate that there is some identifiable drug abuse problem among a sufficient number of those subject to the testing, such that testing that group of students will actually redress its drug problem.” Id., at 1278. The Court of Appeals then held that because the School District failed to demonstrate such a problem existed among Tecumseh students participating in competitive extracurricular activities, the Policy was unconstitutional. We granted certiorari, 534 U. S. 1015 (2001), and now reverse.

II

The Fourth Amendment to the United States Constitution protects “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” Searches by public school officials, such as the collection of urine samples, implicate Fourth Amendment interests. See Vernonia, supra, at 652; cf. New Jersey v. T. L. O., 469 U. S. 325, 334 (1985). We must therefore review the School District’s Policy for “reasonableness,” which is the touchstone of the constitutionality of a governmental search.

In the criminal context, reasonableness usually requires a showing of probable cause. See, e. g., Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 619 (1989). The probable-cause standard, however, “is peculiarly related to criminal investigations” and may be unsuited to determining the reasonableness of administrative searches where the “Government seeks to prevent the development of hazardous conditions.” Treasury Employees v. Von Raab, 489 U. S. 656, 667-668 (1989) (internal quotation marks and citations omitted) (collecting eases). The Court has also held that a warrant and finding of probable cause are unnecessary in the public school context because such requirements “ ‘would unduly interfere with the maintenance of the swift and infor*829mal disciplinary procedures [that are] needed.’ ” Vernonia, supra, at 653 (quoting T L. O., supra, at 340-341).

Given that the School District’s Policy is not in any way related to the conduct of criminal investigations, see Part II-B, infra, respondents do not contend that the School District requires probable cause before testing students for drug use. Respondents instead argue that drug testing must be based at least on some level of individualized suspicion. See Brief for Respondents 12-14. It is true that we generally determine the reasonableness of a search by balancing the nature of the intrusion on the individual’s privacy against the promotion of legitimate governmental interests. See Delaware v. Prouse, 440 U. S. 648, 654 (1979). But we have long held that “the Fourth Amendment imposes no irreducible requirement of [individualized] suspicion.” United States v. Martinez-Fuerte, 428 U. S. 543, 561 (1976). “[I]n certain limited circumstances, the Government’s need to discover such latent or hidden conditions, or to prevent their development, is sufficiently compelling to justify the intrusion on privacy entailed by conducting such searches without any measure of individualized suspicion.” Von Raab, supra, at 668; see also Skinner, supra, at 624. Therefore, in the context of safety and administrative regulations, a search unsupported by probable cause may be reasonable “when 'special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable.’” Griffin v. Wisconsin, 483 U. S. 868, 873 (1987) (quoting T. L. O., supra, at 351 (Blackmun, J., concurring in judgment)); see also Vernonia, supra, at 653; Skinner, supra, at 619.

Significantly, this Court has previously held that “special needs” inhere in the public school context. See Vernonia, supra, at 653; T. L. O., supra, at 339-340. While schoolchildren do not shed their constitutional rights when they enter the schoolhouse, see Tinker v. Des Moines Independent Community School Dist., 393 U. S. 503, 506 (1969), “Fourth *830Amendment rights . . . are different in public schools than elsewhere; the ‘reasonableness’ inquiry cannot disregard the schools’ custodial and tutelary responsibility for children.” Vernonia, 515 U. S., at 656. In particular, a finding of individualized suspicion may not be necessary when a school conducts drug testing.

In Vernonia, this Court held that the suspicionless drug testing of athletes was constitutional. The Court, however, did not simply authorize all school drug testing, but rather conducted a fact-specific balancing of the intrusion on the children’s Fourth Amendment rights against the promotion of legitimate governmental interests. See id., at 652-653. Applying the principles of Vernonia to the somewhat different facts of this case, we conclude that Tecumseh’s Policy is also constitutional.

A

We first consider the nature of the privacy interest allegedly compromised by the drug testing. See id., at 654. As in Vernonia, the context of the public school environment serves as the backdrop for the analysis of the privacy interest at stake and the reasonableness of the drug testing policy in general. See ibid. (“Central... is the fact that the subjects of the Policy are (1) children, who (2) have been committed to the temporary custody of the State as schoolmaster”); see also id., at 665 (“The most significant element in this case is the first we discussed: that the Policy was undertaken in furtherance of the government’s responsibilities, under a public school system, as guardian and tutor of children entrusted to its care”); ibid. (“[W]hen the government acts as guardian and tutor the relevant question is whether the search is one that a reasonable guardian and tutor might undertake”).

A student’s privacy interest is limited in a public school environment where the State is responsible for maintaining discipline, health, and safety. Schoolchildren are routinely required to submit to physical examinations and vaccinations *831against disease. See id., at 656. Securing order in the school environment sometimes requires that students be subjected to greater controls than those appropriate for adults. See T. L. O., 469 U. S., at 350 (Powell, J., concurring) (“Without first establishing discipline and maintaining order, teachers cannot begin to educate their students. And apart from education, the school has the obligation to protect pupils from mistreatment by other children, and also to protect teachers themselves from violence by the few students whose conduct in recent years has prompted national concern”).

Respondents argue that because children participating in nonathletic extracurricular activities are not subject to regular physicals and communal undress, they have a stronger expectation of privacy than the athletes tested in Vernonia. See Brief for Respondents 18-20. This distinction, however, was not essential to our decision in Vernonia, which depended primarily upon the school’s custodial responsibility and authority.3

In any event, students who participate in competitive extracurricular activities voluntarily subject themselves to many of the same intrusions on their privacy as do athletes.4 *832Some of these clubs and activities require occasional off-campus travel and communal undress. All of them have their own rules and requirements for participating students that do not apply to the student body as a whole. 115 F. Supp. 2d, at 1289-1290. For example, each of the competitive extracurricular activities governed by the Policy must abide by the rules of the Oklahoma Secondary Schools Activities Association, and a faculty sponsor monitors the students for compliance with the various rules dictated by the clubs and activities. See id., at 1290. This regulation of extracurricular activities further diminishes the expectation of privacy among schoolchildren. Cf. Vernonia, supra, at 657 (“Somewhat like adults who choose to participate in a closely regulated industry, students who voluntarily participate in school athletics have reason to expect intrusions upon normal rights and privileges, including privacy” (internal quotation marks omitted)). We therefore conclude that the students affected by this Policy have a limited expectation of privacy.

B

Next, we consider the character of the intrusion imposed by the Policy. See Vernonia, supra, at 658. Urination is “an excretory function traditionally shielded by great privacy.” Skinner, 489 U. S., at 626. But the “degree of intrusion” on one’s privacy caused by collecting a urine sample “depends upon the manner in which production of the urine sample is monitored.” Vernonia, supra, at 658.

Under the Policy, a faculty monitor waits outside the closed restroom stall for the student to produce a sample and must “listen for the normal sounds of urination in order to guard against tampered specimens and to insure an accurate chain of custody.” App. 199. The monitor then pours the sample into two bottles that are sealed and placed into a mailing pouch along with a consent form signed by the student. This procedure is virtually identical to that reviewed in Vernonia, except that it additionally protects privacy by *833allowing male students to produce their samples behind a closed stall. Given that we considered the method of collection in Vernonia a “negligible” intrusion, 515 U. S., at 658, the method here is even less problematic.

In addition, the Policy clearly requires that the test results be kept in confidential files separate from a student’s other educational records and released to school personnel only on a “need to know” basis. Respondents nonetheless contend that the intrusion on students’ privacy is significant because the Policy fails to protect effectively against the disclosure of confidential information and, specifically, that the school “has been careless in protecting that information: for example, the Choir teacher looked at students’ prescription drug lists and left them where other students could see them.” Brief for Respondents 24. But the choir teacher is someone with a “need to know,” because during off-campus trips she needs to know what medications are taken by her students. Even before the Policy was enacted the choir teacher had access to this information. See App. 132. In any event, there is no allegation that any other student did see such information. This one example of alleged carelessness hardly increases the character of the intrusion.

Moreover, the test results are not turned over to any law enforcement authority. Nor do the test results here lead to the imposition of discipline or have any academic consequences. Cf. Vernonia, supra, at 658, and n. 2. Rather, the only consequence of a failed drug test is to limit the student’s privilege of participating in extracurricular activities. Indeed, a student may test positive for drugs twice and still be allowed to participate in extracurricular activities. After the first positive test, the school contacts the student’s parent or guardian for a meeting. The student may continue to participate in the activity if within five days of the meeting the student shows proof of receiving drug counseling and submits to a second drug test in two weeks. For the second positive test, the student is suspended from participation in *834all extracurricular activities for 14 days, must complete four hours of substance abuse counseling, and must submit to monthly drug tests. Only after a third positive test will the student be suspended from participating in any extracurricular activity for the remainder of the school year, or 88 school days, whichever is longer. See App. 201-202.

Given the minimally intrusive nature of the sample collection and the limited uses to which the test results are put, we conclude that the invasion of students’ privacy is not significant.

C

Finally, this Court must consider the nature and immediacy of the government’s concerns and the efficacy of the Policy in meeting them. See Vernonia, 515 U. S., at 660. This Court has already articulated in detail the importance of the governmental concern in preventing drug use by schoolchildren. See id., at 661-662. The drug abuse problem among our Nation’s youth has hardly abated since Vernonia was decided in 1995. In fact, evidence suggests that it has only grown worse.5 As in Vernonia, “the necessity for the State to act is magnified by the fact that this evil is being visited not just upon individuals at large, but upon children for whom it has undertaken a special responsibility of care and direction.” Id., at 662. The health and safety risks identified in Vernonia apply with equal force to Tecumseh’s children. Indeed, the nationwide drug epidemic makes the war against drugs a pressing concern in every school.

Additionally, the School District in this case has presented specific evidence of drug use at Tecumseh schools. Teachers testified that they had seen students who appeared to be *835under the influence of drugs and that they had heard students speaking-openly about using drugs. See, e. g., App. 72 (deposition of Dean Rogers); id., at 115 (deposition of Sheila Evans). A drug dog found marijuana cigarettes near the school parking lot. Police officers once found drugs or drug paraphernalia in a car driven by a Future Farmers of America member. And the school board president reported that people in the community were calling the board to discuss the ‘‘drug situation.” See 115 F. Supp. 2d, at 1285-1286. We decline to second-guess the finding of the District Court that “[viewing the evidence as a whole, it cannot be reasonably disputed that the [School District] was faced with a ‘drug problem’ when it adopted the Policy.” Id., at 1287.

Respondents consider the proffered evidence insufficient and argue that there is no “real and immediate interest” to justify a policy of drug testing nonathletes. Brief for Respondents 32. We have recognized, however, that “[a] demonstrated problem of drug abuse . . . [is] not in all cases necessary to the validity of a testing regime,” but that some showing does “shore up an assertion of special need for a suspieionless general search program.” Chandler v. Miller, 520 U. S. 305, 319 (1997). The School District has provided sufficient evidence to shore up the need for its drug testing program.

Furthermore, this Court has not required a particularized or pervasive drug problem before allowing the government to conduct suspicionless drug testing. For instance, in Von Raab the Court upheld the drug testing of customs officials on a purely preventive basis, without any documented history of drug use by such officials. See 489 U. S., at 673. In response to the lack of evidence relating to drug use, the Court noted generally that “drug abuse is one of the most serious problems confronting our society today,” and that programs to prevent and detect drug use among customs officials could not be deemed unreasonable. Id., at 674; cf. Skinner, 489 U. S., at 607, and n. 1 (noting nationwide *836studies that identified on-the-job alcohol and drug use by railroad employees). Likewise, the need to prevent and deter the substantial harm of childhood drug use provides the necessary immediacy for a school testing policy. Indeed, it would make little sense to require a school district to wait for a substantial portion of its students to begin using drugs before it was allowed to institute a drug testing program designed to deter drug use.

Given the nationwide epidemic of drug use, and the evidence of increased drug use in Tecumseh schools, it was entirely reasonable for the School District to enact this particular drug testing policy. We reject the Court of Appeals’ novel test that “any district seeking to impose a random sus-picionless drug testing policy as a condition to participation in a school activity must demonstrate that there is some identifiable drug abuse problem among a sufficient number of those subject to the testing, such that testing that group of students will actually redress its drug problem.” 242 F. 3d, at 1278. Among other problems, it would be difficult to administer such a test. As we cannot articulate a threshold level of drug use that would suffice to justify a drug testing program for schoolchildren, we refuse to fashion what would in effect be a constitutional quantum of drug use necessary to show a “drug problem.”

Respondents also argue that the testing of nonathletes does not implicate any safety concerns, and that safety is a “crucial factor” in applying the special needs framework. Brief for Respondents 25-27. They contend that there must be “surpassing safety interests,” Skinner, supra, at 634, or “extraordinary safety and national security hazards,” Von Raab, supra, at 674, in order to override the usual protections of the Fourth Amendment. See Brief for Respondents 25-26. Respondents are correct that safety factors into the special needs analysis, but the safety interest furthered by drug testing is undoubtedly substantial for all children, athletes and nonathletes alike. We know all too well that drug *837use carries a variety of health risks for children, including death from overdose.

We also reject respondents’ argument that drug testing must presumptively be based upon an individualized reasonable suspicion of wrongdoing because such a testing regime would be less intrusive. See id., at 12-16. In this context, the Fourth Amendment does not require a finding of individualized suspicion, see supra, at 829, and we decline to impose such a requirement on schools attempting to prevent and detect drug use by students. Moreover, we question whether testing based on individualized suspicion in fact would be less intrusive. Such a regime would place an additional burden on public school teachers who are already tasked with the difficult job of maintaining order and discipline. A program of individualized suspicion might unfairly target members of unpopular groups. The fear of lawsuits resulting from such targeted searches may chill enforcement of the program, rendering it ineffective in combating drug use. See Vernonia, 515 U. S., at 668-664 (offering similar reasons for why “testing based on ‘suspicion’ of drug use would not be better, but worse”). In any case, this Court has repeatedly stated that reasonableness under the Fourth Amendment does not require employing the least intrusive means, because “[t]he logic of such elaborate less-restrictive-alternative arguments could raise insuperable barriers to the exercise of virtually all search-and-seizure powers.” Martinez-Fuerte, 428 U. S., at 556-557, n. 12; see also Skinner, supra, at 624 (“[A] showing of individualized suspicion is not a constitutional floor, below which a search must be presumed unreasonable”).

Finally, we find that testing students who participate in extracurricular activities is a reasonably effective means of addressing the School District’s legitimate concerns in preventing, deterring, and detecting drug use. While in Ver-nonia there might have been a closer fit between the testing of athletes and the trial court’s finding that the drug problem *838was “fueled by the ‘role model’ effect of athletes’ drug use,” such a finding was not essential to the holding. 515 U. S., at 663; cf. id., at 684-685 (O’Connor, J., dissenting) (questioning the extent of the drug problem, especially as applied to athletes). Vernonia did not require the school to test the group of students most likely to use drugs, but rather considered the constitutionality of the program in the context of the public school’s custodial responsibilities. Evaluating the Policy in this context, we conclude that the drug testing of Tecumseh students who participate in extracurricular activities effectively serves the School District’s interest in protecting the safety and health of its students.

HH l-H l — H

Within the limits of the Fourth Amendment, local school boards must assess the desirability of drug testing schoolchildren. In upholding the constitutionality of the Policy, we express no opinion as to its wisdom. Rather, we hold only that Tecumseh’s Policy is a reasonable means of furthering the School District’s important interest in preventing and deterring drug use among its schoolchildren. Accordingly, we reverse the judgment of the Court of Appeals.

It is so ordered.

Justice Breyer,

concurring.

I agree with the Court that Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), governs this case and requires reversal of the Tenth Circuit’s decision. The school’s drug testing program addresses a serious national problem by focusing upon demand, avoiding the use of criminal or disciplinary sanctions, and relying upon professional counseling and treatment. See App. 201-202. In my view, this program does not violate the Fourth Amendment’s prohibition of “unreasonable searches and seizures.” I reach this conclusion primarily for the reasons given by the Court, but I would *839emphasize several underlying considerations, which I understand to be consistent with the Court’s opinion.

I

In respect to the school’s need for the drug testing program, I would emphasize the following: First, the drug problem in our Nation’s schools is serious in terms of size, the kinds of drugs being used, and the consequences of that use both for our children and the rest of us. See, e. g., White House Nat. Drug Control Strategy 25 (Feb. 2002) (drug abuse leads annually to about 20,000 deaths, $160 billion in economic costs); Department of Health and Human Services, L. Johnston et al., Monitoring the Future: National Results on Adolescent Drug Use, Overview of Key Findings 5 (2001) (Monitoring the Future) (more than one-third of all students have used illegal drugs before completing the eighth grade; more than half before completing high school); ibid, (about 30% of all students use drugs other than marijuana prior to completing high school (emphasis added)); National Center on Addiction and Substance Abuse, Malignant Neglect: Substance Abuse and America’s Schools 15 (Sept. 2001) (Malignant Neglect) (early use leads to later drug dependence); Nat. Drug Control Strategy, supra, at 1 (same).

Second, the government’s emphasis upon supply side interdiction apparently has not reduced teenage use in recent years. Compare R. Perl, CRS Issue Brief for Congress, Drug Control: International Policy and Options CRS-1 (Dec. 12, 2001) (supply side programs account for 66% of the federal drug control budget), with Partnership for a Drug-Free America, 2001 Partnership Attitude Tracking Study: Key Findings 1 (showing increase in teenage drug use in early 1990’s, peak in 1997, holding steady thereafter); 2000-2001 PRIDE National Summary: Alcohol, Tobacco, Illicit Drugs, Violence and Related Behaviors, Grades 6 thru 12 (Jul. 16, 2002), http://www.pridesurveys.com/main/supportfiles/ natsum00.pdf, p. 15 (slight rise in high school drug use in *8402000-2001); Monitoring the Future, Table 1 (lifetime prevalence of drug use increasing over last 10 years).

Third, public school systems must find effective ways to deal with this problem. Today’s public expects its schools not simply to teach the fundamentals, but “to shoulder the burden of feeding students breakfast and lunch, offering before and after school child care services, and providing medical and psychological services,” all in a school environment that is safe and encourages learning. Brief for National School Boards Association et al. as Amici Curiae 3-4. See also Bethel School Dist. No. 403 v. Fraser, 478 U. S. 675, 681 (1986) (Schools “ ‘prepare pupils for citizenship in the Republic [and] inculcate the habits and manners of civility as values in themselves conductive to happiness and as indispensable to the practice of self-government in the community and the nation’ ”) (quoting C. Beard & M. Beard, New Basic History of the United States 228 (1968)). The law itself recognizes these responsibilities with the phrase in loco parentis — a phrase that draws its legal force primarily from the needs of younger students (who here are necessarily grouped together with older high school students) and which reflects, not that a child or adolescent lacks an interest in privacy, but that a child’s or adolescent’s school-related privacy interest, when compared to the privacy interests of an adult, has different dimensions. Cf. Vernonia, supra, at 654-655. A public school system that fails adequately to carry out its responsibilities may well see parents send their children to private or parochial school instead — with help from the State. See Zelman v. Simmons-Harris, ante, p. 639.

Fourth, the program at issue here seeks to discourage demand for drugs by changing the school’s environment in order to combat the single most important factor leading schoolchildren to take drugs, namely, peer pressure. Malignant Neglect 4 (students “whose friends use illicit drugs are more than 10 times likelier to use illicit drugs than those whose friends do not”). It offers the adolescent a nonthreat*841ening reason to decline his friend’s drug-use invitations, namely, that he intends to play baseball, participate in debate, join the band, or engage in any one of half a dozen useful, interesting, and important activities.

II

In respect to the privacy-related burden that the drug testing program imposes upon students, I would emphasize the following: First, not everyone would agree with this Court’s characterization of the privacy-related significance of urine sampling as “‘negligible.’” Ante, at 833 (quoting Vernonia, 515 U. S., at 658). Some find the procedure no more intrusive than a routine medical examination, but others are seriously embarrassed by the need to provide a urine sample with someone listening “outside the closed restroom stall,” ante, at 832. When trying to resolve this kind of close question involving the interpretation of constitutional values, I believe it important that the school board provided an opportunity for the airing of these differences at public meetings designed to give the entire community “the opportunity to be able to participate” in developing the drug policy. App. 87. The board used this democratic, participatory process to uncover and to resolve differences, giving weight to the fact that the process, in this instance, revealed little, if any, objection to the proposed testing program.

Second, the testing program avoids subjecting the entire school to testing. And it preserves an option for a conscientious objector. He can refuse testing while paying a price (nonparticipation) that is serious, but less severe than expulsion from the school.

Third, a contrary reading of the Constitution, as requiring “individualized suspicion” in this public school context, could well lead schools to push the boundaries of “individualized suspicion” to its outer limits, using subjective criteria that may “unfairly target members of impopular groups,” ante, at 837, or leave those whose behavior is slightly abnormal *842stigmatized in the minds of others. See Belsky, Random vs. Suspicion-Based Drug Testing in the Public Schools — A Surprising Civil Liberties Dilemma, 27 Okla. City U. L. Rev. 1, 20-21 (forthcoming 2002) (listing court-approved factors justifying suspicion-based drug testing, including tiredness, overactivity, quietness, boisterousness, sloppiness, excessive meticulousness, and tardiness). If so, direct application of the Fourth Amendment’s prohibition against “unreasonable searches and seizures” will further that Amendment’s liberty-protecting objectives at least to the same extent as application of the mediating “individualized suspicion” test, where, as here, the testing program is neither criminal nor disciplinary in nature.

* * *

I cannot know whether the school’s drug testing program will work. But, in my view, the Constitution does not prohibit the effort. Emphasizing the considerations I have mentioned, along with others to which the Court refers, I conclude that the school’s drug testing program, constitutionally speaking, is not “unreasonable.” And I join the Court’s opinion.

Justice O’Connor,

with whom Justice Souter joins, dissenting.

I dissented in Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), and continue to believe that case was wrongly decided. Because Vernonia is now this Court’s precedent, and because I agree that petitioners’ program fails even under the balancing approach adopted in that case, I join Justice Ginsburg’s dissent.

Justice Ginsburg,

with whom Justice Stevens, Justice O’Connor, and Justice Souter join, dissenting.

Seven years ago, in Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), this Court determined that a school *843district’s policy of randomly testing the urine of its student athletes for illicit drugs did not violate the Fourth Amendment. In so ruling, the Court emphasized that drug use “increase[d] the risk of sports-related injury” and that Ver-nonia’s athletes were the “leaders” of an aggressive local “drug culture” that had reached “‘epidemic proportions.’” Id., at 649. Today, the Court relies upon Vernonia to permit a school district with a drug problem its superintendent repeatedly described as “not. . . major,” see App. 180, 186, 191, to test the urine of an academic team member solely by reason of her participation in a nonathletic, competitive extracurricular activity — participation associated with neither special dangers from, nor particular predilections for, drug use.

“[T]he legality of a search of a student,” this Court has instructed, “should depend simply on the reasonableness, under all the circumstances, of the search.” New Jersey v. T. L. O., 469 U. S. 325, 341 (1985). Although “ ‘special needs’ inhere in the public school context,” see ante, at 829 (quoting Vernonia, 515 U. S., at 653), those needs are not so expansive or malleable as to render reasonable any program of student drug testing a school district elects to install. The particular testing program upheld today is not reasonable; it is capricious, even perverse: Petitioners’ policy targets for testing a student population least likely to be at risk from illicit drugs and their damaging effects. I therefore dissent.

1 — <

A

A search unsupported by probable cause nevertheless may be consistent with the Fourth Amendment “when special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable.” Griffin v. Wisconsin, 483 U. S. 868, 873 (1987) (internal quotation marks omitted). In Vernonia, this Court made clear that “such ‘special needs’ . . . exist in the public school con*844text.” 515 U. S., at 653 (quoting Griffin, 483 U. S., at 873). The Court observed:

“[Wjhile children assuredly do not ‘shed their constitutional rights ... at the schoolhouse gate,’ Tinker v. Des Moines Independent Community School Dist., 393 U. S. 503, 506 (1969), the nature of those rights is what is appropriate for children in school.... Fourth Amendment rights, no less than First and Fourteenth Amendment rights, are different in public schools than elsewhere; the ‘reasonableness’ inquiry cannot disregard the schools’ custodial and tutelary responsibility for children.” 515 U. S., at 655-656 (other citations omitted).

The Vernonia Court concluded that a public school district facing a disruptive and explosive drug abuse problem sparked by members of its athletic teams had “special needs” that justified suspicionless testing of district athletes as a condition of their athletic participation.

This case presents circumstances dispositively different from those of Vernonia. True, as the Court stresses, Tecumseh students participating in competitive extracurricular activities other than athletics share two relevant characteristics with the athletes of Vernonia. First, both groups attend public schools. “[0]ur decision in Vernonia,” the Court states, “depended primarily upon the school’s custodial responsibility and authority.” Ante, at 831; see also ante, at 840 (Breyer, J., concurring) (school districts act in loco parentis). Concern for student health and safety is basic to the school’s caretaking, and it is undeniable that “drug use carries a variety of health risks for children, including death from overdose.” Ante, at 836-837 (majority opinion).

Those risks, however, are present for all schoolchildren. Vernonia cannot be read to endorse invasive and suspicion-less drug testing of all students upon any evidence of drug use, solely because drugs jeopardize the life and health of those who use them. Many children, like many adults, en*845gage in dangerous activities on their own time; that the children are enrolled in school scarcely allows government to monitor all such activities. If a student has a reasonable subjective expectation of privacy in the personal items she brings to school, see T. L. O., 469 U. S., at 338-339, surely she has a similar expectation regarding the chemical composition of her urine. Had the Vernonia Court agreed that public school attendance, in and of itself, permitted the State to test each student’s blood or urine for drugs, the opinion in Vernonia could have saved many words. See, e. g., 515 U. S., at 662 (“[I]t must not be lost sight of that [the Vernonia School District] program is directed ... to drug use by school athletes, where the risk of immediate physical harm to the drug user or those with whom he is playing his sport is particularly high.”).

The second commonality to which the Court points is the voluntary character of both interscholastic athletics and other competitive extracurricular activities. “By choosing to ‘go out for the team,’ [school athletes] voluntarily subject themselves to a degree of regulation even higher than that imposed on students generally.” Id., at 657. Comparably, the Court today observes, “students who participate in competitive extracurricular activities voluntarily subject themselves to” additional rules not applicable to other students. Ante, at 831.

The comparison is enlightening. While extracurricular activities are “voluntary” in the sense that they are not required for graduation, they are part of the school’s educational program; for that reason, the petitioner (hereinafter School District) is justified in expending public resources to ■ make them available. Participation in such activities is a key component of school life, essential in reality for students applying to college, and, for all participants, a significant contributor to the breadth and quality of the educational experience. See Brief for Respondents 6; Brief for American Academy of Pediatrics et al. as Amici Curiae 8-9. Students *846“volunteer” for extracurricular pursuits in the same way they might volunteer for honors classes: They subject themselves to additional requirements, but they do so in order to take full advantage of the education offered them. Cf. Lee v. Weisman, 505 U. S. 577, 595 (1992) (“Attendance may not be required by official decree, yet it is apparent that a student is not free to absent herself from the graduation exercise in any real sense of the term ‘voluntary,’ for absence would require forfeiture of those intangible benefits which have motivated the student through youth and all her high school years.”).

Voluntary participation in athletics has a distinctly different dimension: Schools regulate student athletes discretely because competitive school sports by their nature require communal undress and, more important, expose students to physical risks that schools have a duty to mitigate. For the very reason that schools cannot offer a program of competitive athletics without intimately affecting the privacy of students, Vernonia reasonably analogized school athletes to “adults who choose to participate in a closely regulated industry.” 515 U. S., at 657 (internal quotation marks omitted). Industries fall within the closely regulated category when the nature of their activities requires substantial government oversight. See, e. g., United States v. Biswell, 406 U. S. 311, 815-316 (1972). Interscholastic athletics similarly require close safety and health regulation; a school’s choir, band, and academic team do not.

In short, Vernonia applied, it did not repudiate, the principle that “the legality of a search of a student should depend simply on the reasonableness, under all the circumstances, of the search.” T. L. O., 469 U. S., at 341 (emphasis added). Enrollment in a public school, and election to participate in school activities beyond the bare minimum that the curriculum requires, are indeed factors relevant to reasonableness, but they do not on their own justify intrusive, suspicionless searches. Vernonia, accordingly, did not rest upon these *847factors; instead, the Court performed what today’s majority aptly describes as a “fact-specific balancing,” ante, at 830. Balancing of that order, applied to the facts now before the Court, should yield a result other than the one the Court announces today.

B

Vernonia initially considered “the nature of the privacy interest upon which the search [there] at issue intrude[d].” 515 U. S., at 654. The Court emphasized that student athletes’ expectations of privacy are necessarily attenuated:

“Legitimate privacy expectations are even less with regard to student athletes. School sports are not for the bashful. They require ‘suiting up’ before each practice or event, and showering and changing afterwards. Public school locker rooms, the usual sites for these activities, are not notable for the privacy they afford. The locker rooms in Vernonia are typical: No individual dressing rooms are provided; shower heads are lined up along a wall, unseparated by any sort of partition or curtain; not even all the toilet stalls have doors. . . . [T]here is an element of communal undress inherent in athletic participation.” Id., at 657 (internal quotation marks omitted).

Competitive extracurricular activities other than athletics, however, serve students of all manner: the modest and shy along with the bold and uninhibited. Activities of the kind plaintiff-respondent Lindsay Earls pursued — choir, show choir, marching band, and academic team — afford opportunities to gain self-assurance, to “come to know faculty members in a less formal setting than the typical classroom,” and to acquire “positive social supports and networks [that] play a critical role in periods of heightened stress.” Brief for American Academy of Pediatrics et al. as Amici Curiae 13.

On “occasional out-of-town trips,” students like Lindsay Earls “must sleep together in communal settings and use *848communal bathrooms.” 242 F. 3d 1264, 1275 (CA10 2001). But those situations are hardly equivalent to the routine communal undress associated with athletics; the School District itself admits that when such trips occur, “public-like restroom facilities,” which presumably include enclosed stalls, are ordinarily available for changing, and that “more modest students” find other ways to maintain their privacy. Brief for Petitioners 34.1

After describing school athletes’ reduced expectation of privacy, the Vernonia Court turned to “the character of the intrusion . . . complained of.” 515 U. S., at 658. Observing that students produce urine samples in a bathroom stall with a coach or teacher outside, Vernonia typed the privacy interests compromised by the process of obtaining samples “negligible.” Ibid. As to the required pretest disclosure of prescription medications taken, the Court assumed that “the School District would have permitted [a student] to provide the requested information in a confidential manner — for example, in a sealed envelope delivered to the testing lab.” Id., at 660. On that assumption, the Court concluded that Vernonia’s athletes faced no significant invasion of privacy.

In this case, however, Lindsay Earls and her parents allege that the School District handled personal information collected under the policy carelessly, with little regard for its confidentiality. Information about students’ prescription drug use, they assert, was routinely viewed by Lindsay’s choir teacher, who left files containing the information unlocked and unsealed, where others, including students, could see them; and test results were given out to all activity sponsors whether or not they had a clear “need to know.” See *849Brief for Respondents 6, 24; App. 105-106, 131. But see id., at 199 (policy requires that “[t]he medication list shall be submitted to the lab in a sealed and confidential envelope and shall not be viewed by district employees”).

In granting summary judgment to the School District, the District Court observed that the District’s “[pjolicy expressly provides for confidentiality of test results, and the Court must assume that the confidentiality provisions will be honored.” 115 F. Supp. 2d 1281, 1293 (WD Okla. 2000). The assumption is unwarranted. Unlike Vernonia, where the District Court held a bench trial before ruling in the School District’s favor, this case was decided by the District Court on summary judgment. At that stage, doubtful matters should not have been resolved in favor of the judgment seeker. See United States v. Diebold, Inc., 369 U. S. 654, 655 (1962) (per curiam) (“On summary judgment the inferences to be drawn from the underlying facts contained in [affidavits, attached exhibits, and depositions] must be viewed in the light most favorable to the party opposing the motion.”); see also 10A C. Wright, A. Miller, & M. Kane, Federal Practice and Procedure § 2716, pp. 274-277 (3d ed. 1998).

Finally, the “nature and immediacy of the governmental concern,” Vernonia, 515 U. S., at 660, faced by the Vernonia School District dwarfed that confronting Tecumseh administrators. Vernonia initiated its drug testing policy in response to an alarming situation: “[A] large segment of the student body, particularly those involved in interscholastic athletics, was in a state of rebellion ... fueled by alcohol and drug abuse as well as the student[s’] misperceptions about the drug culture.” Id., at 649 (internal quotation marks omitted). Tecumseh, by contrast, repeatedly reported to the Federal Government during the period leading up to the adoption of the policy that “types of drugs [other than alcohol and tobacco] including controlled dangerous substances, are present [in the schools] but have not identified themselves as major problems at this time.” 1998-1999 Tecum*850seh School’s Application for Funds under the Safe and Drug-Free Schools and Communities Program, reprinted at App. 191; accord, 1996-1997 Application, reprinted at App. 186; 1995-1996 Application, reprinted at App. 180.2 As the Tenth Circuit observed, “without a demonstrated drug abuse problem among the group being tested, the efficacy of the District’s solution to its perceived problem is . . . greatly diminished.” 242 F. 3d, at 1277.

The School District cites Treasury Employees v. Von Raab, 489 U. S. 656, 673-674 (1989), in which this Court permitted random drug testing of customs agents absent “any perceived drug problem among Customs employees,” given that “drug abuse is one of the most serious problems confronting our society today.” See also Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 607, and n. 1 (1989) (upholding random drug and alcohol testing of railway employees based upon industry-wide, rather than railway-specific, evidence of drug and alcohol problems). The tests in Von Raab and Railway Labor Executives, however, were installed to avoid enormous risks to the lives and limbs of others, not dominantly in response to the health risks to users invariably present in any case of drug use. See Von Raab, 489 U. S., at 674 (drug use by customs agents involved in drug interdiction creates “extraordinary safety and national security hazards”); Railway Labor Executives, 489 U. S., at 628 (railway operators “discharge duties fraught with such risks of injury to others that even a momentary lapse of attention can have disastrous consequences”); see *851also Chandler v. Miller, 520 U. S. 305, 321 (1997) (“Von Raab must be read in its unique context”).

Not only did the Vernonia and Tecumseh districts confront drug problems of distinctly different magnitudes, they also chose different solutions: Vernonia limited its policy to athletes; Tecumseh indiscriminately subjected to testing all participants in competitive extracurricular activities. Urging that “the safety interest furthered by drug testing is undoubtedly substantial for all children, athletes and nonath-letes alike,” ante, at 836, the Court cuts out an element essential to the Vernonia judgment. Citing medical literature on the effects of combining illicit drug use with physical exertion, the Vernonia Court emphasized that “the particular drugs screened by [Vernonia’s] Policy have been demonstrated to pose substantial physical risks to athletes.” 515 U. S., at 662; see also id., at 666 (Ginsburg, J., concurring) (Vernonia limited to “those seeking to engage with others in team sports”). We have since confirmed that these special risks were necessary to our decision in Vernonia. See Chandler, 520 U. S., at 317 (Vernonia “emphasized the importance of deterring drug use by schoolchildren and the risk of injury a drug-using student athlete cast on himself and those engaged with him on the playing field”); see also Ferguson v. Charleston, 532 U. S. 67, 87 (2001) (Kennedy, J., concurring) (Vernonia’s policy had goal of “ ‘[djeterring drug use by our Nation’s schoolchildren,’ and particularly by student-athletes, because ‘the risk of immediate physical harm to the drug user or those with whom he is playing his sport is particularly high’ ”) (quoting Vernonia, 515 U. S., at 661-662).

At the margins, of course, no policy of random drug testing is perfectly tailored to the harms it seeks to address. The School District cites the dangers faced by members of the band, who must “perform extremely precise routines with heavy equipment and instruments in close proximity to other students,” and by Future Farmers of America, who *852“are required to individually control and restrain animals as large as 1500 pounds.” Brief for Petitioners 43. For its part, the United States acknowledges that “the linebacker faces a greater risk of serious injury if he takes the field under the influence of drugs than the drummer in the halftime band,” but parries that “the risk of injury to a student who is under the influence of drugs while playing golf, cross country, or volleyball (sports covered by the policy in Ver-nonia) is scarcely any greater than the risk of injury to a student... handling a 1500-pound steer (as [Future Farmers of America] members do) or working with cutlery or other sharp instruments (as [Future Homemakers of America] members do).” Brief for United States as Amicus Curiae 18. One can demur to the Government’s view of the risks drug use poses to golfers, cf. PGA TOUR, Inc. v. Martin, 532 U. S. 661, 687 (2001) (“golf is a low intensity activity”), for golfers were surely as marginal among the linebackers, sprinters, and basketball players targeted for testing in Ver-nonia as steer-handlers are among the choristers, musicians, and academic-team members subject to urinalysis in Tecumseh.3 Notwithstanding nightmarish images of out-of-control flatware, livestock run amok, and colliding tubas disturbing the peace and quiet of Tecumseh, the great majority of students the School District seeks to test in truth are engaged in activities that are not safety sensitive to an unusual degree. There is a difference between imperfect tailoring and no tailoring at all.

The Vernonia district, in sum, had two good reasons for testing athletes: Sports team members faced special health risks and they “were the leaders of the drug culture.” Vernonia, 515 U. S., at 649. No similar reason, and no other tenable justification, explains Teeumseh’s decision to target *853for testing all participants in every competitive extracurricular activity. See Chandler, 520 U. S., at 319 (drug testing candidates for office held incompatible with Fourth Amendment because program was “not well designed to identify candidates who violate antidrug laws”).

Nationwide, students who participate in extracurricular activities are significantly less likely to develop substance abuse problems than are their less-involved peers. See, e. g., N. Zill, C. Nord, & L. Loomis, Adolescent Time Use, Risky Behavior, and Outcomes 52 (1995) (tenth graders “who reported spending no time in school-sponsored activities were ... 49 percent more likely to have used drugs” than those who spent 1-4 hours per week in such activities). Even if students might be deterred from drug use in order to preserve their extracurricular eligibility, it is at least as likely that other students might forgo their extracurricular involvement in order to avoid detection of their drug use. Tecumseh’s policy thus falls short doubly if deterrence is its aim: It invades the privacy of students who need deterrence least, and risks steering students at greatest risk for substance abuse away from extracurricular involvement that potentially may palliate drug problems.4

To summarize, this case resembles Vernonia only in that the School Districts in both cases conditioned engagement in activities outside the obligatory curriculum on random subjection to urinalysis. The defining characteristics of the two programs, however, are entirely dissimilar. The Vernonia district sought to test a subpopulation of students distinguished by their reduced expectation of privacy, their special *854susceptibility to drug-related injury, and their heavy involvement with drug use. The Tecumseh district seeks to test a much larger population associated with none of these factors. It does so, moreover, without carefully safeguarding student confidentiality and without regard to the program’s untoward effects. A program so sweeping is not sheltered by Vemonia; its unreasonable reach renders it impermissible under the Fourth Amendment.

II

In Chandler, this Court inspected “Georgias requirement that candidates for state office pass a drug test”; we held that the requirement “d[id] not fit within the closely guarded category of constitutionally permissible suspicion-less searches.” 520 U. S., at 309. Georgia’s testing prescription, the record showed, responded to no “concrete danger,” id., at 319, was supported by no evidence of a particular problem, and targeted a group not involved in “high-risk, safety-sensitive tasks,” id., at 321-322. We concluded:

“What is left, after close review of Georgia’s scheme, is the image the State seeks to project. By requiring candidates for public office to submit to drug testing, Georgia displays its commitment to the struggle against drug abuse.... The need revealed, in short, is symbolic, not ‘special,’ as that term draws meaning from our case law.” Ibid.

Close review of Tecumseh’s policy compels a similar conclusion. That policy was not shown to advance the “‘special needs’ [existing] in the public school context [to maintain]... swift and informal disciplinary procedures ... [and] order in the schools,” Vernonia, 515 U. S.,.at 653 (internal quotation marks omitted). See supra, at 846-848, 849-853. What is left is the School District’s undoubted purpose to heighten awareness of its abhorrence of, and strong stand against, drug abuse. But the desire to augment eommunica*855tion of this message does not trump the right of persons— even of children within the schoolhouse gate — to be “secure in their persons . . . against unreasonable searches and seizures.” U. S. Const., Arndt. 4.

In Chandler, the Court referred to a pathmarking dissenting opinion in which “Justice Brandéis recognized the importance of teaching by example: ‘Our Government is the potent, the omnipresent teacher. For good or for ill, it teaches the whole people by its example.’ ” 520 U. S., at 322 (quoting Olmstead v. United States, 277 U. S. 438, 485 (1928)). That wisdom should guide decisionmakers in the instant case: The government is nowhere more a teacher than when it runs a public school.

It is a sad irony that the petitioning School District seeks to justify its edict here by trumpeting “the schools’ custodial and tutelary responsibility for children.” Vernonia, 515 U. S., at 656. In regulating an athletic program or endeavoring to combat an exploding drug epidemic, a school’s custodial obligations may permit searches that would otherwise unacceptably abridge students’ rights. When custodial duties are not ascendant, however, schools’ tutelary obligations to their students require them to “teach by example” by avoiding symbolic measures that diminish constitutional protections. “That [schools] are educating the young for citizenship is reason for scrupulous protection of Constitutional freedoms of the individual, if we are not to strangle the free mind at its source and teach youth to discount important principles of our government as mere platitudes.” West Virginia Bd. of Ed. v. Barnette, 319 U. S. 624, 637 (1943).

* * *

For the reasons stated, I would affirm the judgment of the Tenth Circuit declaring the testing policy at issue unconstitutional.

Justice White

delivered the opinion of the Court.

We granted certiorari in this case to examine the appropriateness of the exclusionary rule as a remedy for searches carried out in violation of the Fourth Amendment by public school authorities. Our consideration of the proper application of the Fourth Amendment to the public schools, however, has led us to conclude that the search that gave rise to *328the case now before us did not violate the Fourth Amendment. Accordingly, we here address only the questions of the proper standard for assessing the legality of searches conducted by public school officials and the application of that standard to the facts of this case.

I

On March 7, 1980, a teacher at Piscataway High School in Middlesex County, N. J., discovered two girls smoking in a lavatory. One of the two girls was the respondent T. L. 0., who at that time was a 14-year-old high school freshman. Because smoking in the lavatory was a violation of a school rule, the teacher took the two girls to the Principal’s office, where they met with Assistant Vice Principal Theodore Choplick. In response to questioning by Mr. Choplick, T. L. O.’s companion admitted that she had violated the rule. T. L. 0., however, denied that she had been smoking in the lavatory and claimed that she did not smoke at all.

Mr. Choplick asked T. L. O. to come into his private office and demanded to see her purse. Opening the purse, he found a pack of cigarettes, which he removed from the purse and held before T. L. O. as he accused her of having lied to him. As he reached into the purse for the cigarettes, Mr. Choplick also noticed a package of cigarette rolling papers. In his experience, possession of rolling papers by high school students was closely associated with the use of marihuana. Suspecting that a closer examination of the purse might yield further evidence of drug use, Mr. Choplick proceeded to search the purse thoroughly. The search revealed a smáll amount of marihuana, a pipe, a number of empty plastic bags, a substantial quantity of money in one-dollar bills, an index card that appeared to be a list of students who owed T. L. O. money, and two letters that implicated T. L. O. in marihuana dealing.

Mr. Choplick notified T. L. O.’s mother and the police, and turned the evidence of drug dealing over to the police. At *329the request of the police, T. L. O.’s mother took her daughter to police headquarters, where T. L. O. confessed that she had been selling marihuana at the high school. On the basis of the confession and the evidence seized by Mr. Choplick, the State brought delinquency charges against T. L. O. in the Juvenile and Domestic Relations Court of Middlesex County.1 Contending that Mr. Choplick’s search of her purse violated the Fourth Amendment, T. L. O. moved to suppress the evidence found in her purse as well as her confession, which, she argued, was tainted by the allegedly unlawful search. The Juvenile Court denied the motion to suppress. State ex rel. T. L. O., 178 N. J. Super. 329, 428 A. 2d 1327 (1980). Although the court concluded that the Fourth Amendment did apply to searches carried out by school officials, it held that

“a school official may properly conduct a search of a student’s person if the official has a reasonable suspicion that a crime has been or is in the process of being committed, or reasonable cause to believe that the search is necessary to maintain school discipline or enforce school policies.” Id., at 341, 428 A. 2d, at 1333 (emphasis in original).

Applying this standard, the court concluded that the search conducted by Mr. Choplick was a reasonable one. The initial decision to open the purse was justified by Mr. Choplick’s well-founded suspicion that T. L. O. had violated the rule forbidding smoking in the lavatory. Once the purse *330was open, evidence of marihuana violations was in plain view, and Mr. Choplick was entitled to conduct a thorough search to determine the nature and extent of T. L. O.’s drug-related activities. Id., at 343, 428 A. 2d, at 1334. Having denied the motion to suppress, the court on March 23, 1981, found T. L. O. to be a delinquent and on January 8, 1982, sentenced her to a year’s probation.

On appeal from the final judgment of the Juvenile Court, a divided Appellate Division affirmed the trial court’s finding that there had been no Fourth Amendment violation, but vacated the adjudication of delinquency and remanded for a determination whether T. L. O. had knowingly and voluntarily waived her Fifth Amendment rights before confessing. State ex rel. T. L. O., 185 N. J. Super. 279, 448 A. 2d 493 (1982). T. L. O. appealed the Fourth Amendment ruling, and the Supreme Court of New Jersey reversed the judgment of the Appellate Division and ordered the suppression of the evidence found in T. L. O.’s purse. State ex rel. T. L. O., 94 N. J. 331, 463 A. 2d 934 (1983).

The New Jersey Supreme Court agreed with the lower courts that the Fourth Amendment applies to searches conducted by school officials. The court also rejected the State of New Jersey’s argument that the exclusionary rule should not be employed to prevent the use in juvenile proceedings of evidence unlawfully seized by school officials. Declining to consider whether applying the rule to the fruits of searches by school officials would have any deterrent value, the court held simply that the precedents of this Court establish that “if an official search violates constitutional rights, the evidence is not admissible in criminal proceedings.” Id., at 341, 463 A. 2d, at 939 (footnote omitted).

With respect to the question of the legality of the search before it, the court agreed with the Juvenile Court that a warrantless search by a school official does not violate the Fourth Amendment so long as the official “has reasonable grounds to believe that a student possesses evidence of illegal *331activity or activity that would interfere with school discipline and order.” Id., at 346, 463 A. 2d, at 941-942. However, the court, with two justices dissenting, sharply disagreed with the Juvenile Court’s conclusion that the search of the purse was reasonable. According to the majority, the contents of T. L. O.’s purse had no bearing on the accusation against T. L. 0., for possession of cigarettes (as opposed to smoking them in the lavatory) did not violate school rules, and a mere desire for evidence that would impeach T. L. O.’s claim that she did not smoke cigarettes could not justify the search. Moreover, even if a reasonable suspicion that T. L. O. had cigarettes in her purse would justify a search, Mr. Choplick had no such suspicion, as no one had furnished him with any specific information that there were cigarettes in the purse. Finally, leaving aside the question whether Mr. Choplick was justified in opening the purse, the court held that the evidence of drug use that he saw inside did not justify the extensive “rummaging” through T. L. O.’s papers and effects that followed. Id., at 347, 463 A. 2d, at 942-943.

We granted the State of New Jersey’s petition for certio-rari. 464 U. S. 991 (1983). Although the State had argued in the Supreme Court of New Jersey that the search of T. L. O.’s purse did not violate the Fourth Amendment, the petition for certiorari raised only the question whether the exclusionary rule should operate to bar consideration in juvenile delinquency proceedings of evidence unlawfully seized by a school official without the involvement of law enforcement officers. When this case was first argued last Term, the State conceded for the purpose of argument that the standard devised by the New Jersey Supreme Court for determining the legality of school searches was appropriate and that the court had correctly applied that standard; the State contended only that the remedial purposes of the exclusionary rule were not well served by applying it to searches conducted by public authorities not primarily engaged in law enforcement.

*332Although we originally granted certiorari to decide the issue of the appropriate remedy in juvenile court proceedings for unlawful school searches, our doubts regarding the wisdom of deciding that question in isolation from the broader question of what limits, if any, the Fourth Amendment places on the activities of school authorities prompted us to order reargument on that question.2 Having heard argument on *333the legality of the search of T. L. O.’s purse, we are satisfied that the search did not violate the Fourth Amendment.3

II

In determining whether the search at issue in this case violated the Fourth Amendment, we are faced initially with the question whether that Amendment’s prohibition on unreasonable searches and seizures applies to searches conducted by public school officials. We hold that it does.

*334It is now beyond dispute that “the Federal Constitution, by virtue of the Fourteenth Amendment, prohibits unreasonable searches and seizures by state officers.” Elkins v. United States, 364 U. S. 206, 213 (1960); accord, Mapp v. Ohio, 367 U. S. 643 (1961); Wolf v. Colorado, 338 U. S. 25 (1949). Equally indisputable is the proposition that the Fourteenth Amendment protects the rights of students against encroachment by public school officials:

“The Fourteenth Amendment, as now applied to the States, protects the citizen against the State itself and all of its creatures — Boards of Education not excepted. These have, of course, important, delicate, and highly discretionary functions, but none that they may not perform within the limits of the Bill of Rights. That they are educating the young for citizenship is reason for scrupulous protection of Constitutional freedoms of the individual, if we are not to strangle the free mind at its source and teach youth to discount important principles of our government as mere platitudes.” West Virginia State Bd. of Ed. v. Barnette, 319 U. S. 624, 637 (1943).

These two propositions — that the Fourth Amendment applies to the States through the Fourteenth Amendment, and that the actions of public school officials are subject to the limits placed on state action by the Fourteenth Amendment — might appear sufficient to answer the suggestion that the Fourth Amendment does not proscribe unreasonable searches by school officials. On reargument, however, the State of New Jersey has argued that the history of the Fourth Amendment indicates that the Amendment was intended to regulate only searches and seizures carried out by law enforcement officers; accordingly, although public school officials are concededly state agents for purposes of the Fourteenth Amendment, the Fourth Amendment creates no rights enforceable against them.4

*335It may well be true that the evil toward which the Fourth Amendment was primarily directed was the resurrection of the pre-Revolutionary practice of using general warrants or “writs of assistance” to authorize searches for contraband by officers of the Crown. See United States v. Chadwick, 433 U. S. 1, 7-8 (1977); Boyd v. United States, 116 U. S. 616, 624-629 (1886). But this Court has never limited the Amendment’s prohibition on unreasonable searches and seizures to operations conducted by the police. Rather, the Court has long spoken of the Fourth Amendment’s strictures as restraints imposed upon “governmental action” — that is, “upon the activities of sovereign authority.” Burdeau v. McDowell, 256 U. S. 465, 475 (1921). Accordingly, we have held the Fourth Amendment applicable to the activities of civil as well as criminal authorities: building inspectors, see Camara v. Municipal Court, 387 U. S. 523, 528 (1967), Occupational Safety and Health Act inspectors, see Marshall v. Barlow’s, Inc., 436 U. S. 307, 312-313 (1978), and even firemen entering privately owned premises to battle a fire, see Michigan v. Tyler, 436 U. S. 499, 506 (1978), are all subject to the restraints imposed by the Fourth Amendment. As we observed in Camara v. Municipal Court, supra, “[t]he basic purpose of this Amendment, as recognized in countless decisions of this Court, is to safeguard the privacy and security of individuals against arbitrary invasions by governmental officials.” 387 U. S., at 528. Because the individual’s interest in privacy and personal security “suffers whether the government’s motivation is to investigate violations of criminal laws or breaches of other statutory or regulatory standards,” Marshall v. Barlow’s, Inc., supra, at 312-313, it would be “anomalous to say that the individual and his private property are fully protected by the Fourth Amendment only when the individual is suspected of criminal behavior.” Camara v. Municipal Court, supra, at 530.

*336Notwithstanding the general applicability of the Fourth Amendment to the activities of civil authorities, a few courts have concluded that school officials are exempt from the dictates of the Fourth Amendment by virtue of the special nature of their authority over schoolchildren. See, e. g., R. C. M. v. State, 660 S. W. 2d 552 (Tex. App. 1983). Teachers and school administrators, it is said, act in loco parentis in their dealings with students: their authority is that of the parent, not the State, and is therefore not subject to the limits of the Fourth Amendment. Ibid.

Such reasoning is in tension with contemporary reality and the teachings of this Court. We have held school officials subject to the commands of the First Amendment, see Tinker v. Des Moines Independent Community School District, 393 U. S. 503 (1969), and the Due Process Clause of the Fourteenth Amendment, see Goss v. Lopez, 419 U. S. 565 (1975). If school authorities are state actors for purposes of the constitutional guarantees of freedom of expression and due process, it is difficult to understand why they should be deemed to be exercising parental rather than public authority when conducting searches of their students. More generally, the Court has recognized that “the concept of parental delegation” as a source of school authority is not entirely “consonant with compulsory education laws.” Ingraham v. Wright, 430 U. S. 651, 662 (1977). Today’s public school officials do not merely exercise authority voluntarily conferred on them by individual parents; rather, they act in furtherance of publicly mandated educational and disciplinary policies. See, e. g., the opinion in State ex rel. T. L. O., 94 N. J., at 343, 463 A. 2d, at 934, 940, describing the New Jersey statutes regulating school disciplinary policies and establishing the authority of school officials over their students. In carrying out searches and other disciplinary functions pursuant to such policies, school officials act as representatives of the State, not merely as surrogates for the parents, and they *337cannot claim the parents’ immunity from the strictures of the Fourth Amendment.

Ill

To hold that the Fourth Amendment applies to searches conducted by school authorities is only to begin the inquiry into the standards governing such searches. Although the underlying command of the Fourth Amendment is always that searches and seizures be reasonable, what is reasonable depends on the context within which a search takes place. The determination of the standard of reasonableness governing any specific class of searches requires “balancing the need to search against the invasion which the search entails.” Camara v. Municipal Court, supra, at 536-537. On one side of the balance are arrayed the individual’s legitimate expectations of privacy and personal security; on the other, the government’s need for effective methods to deal with breaches of public order.

We have recognized that even a limited search of the person is a substantial invasion of privacy. Terry v. Ohio, 392 U. S. 1, 24-25 (1967). We have also recognized that searches of closed items of personal luggage are intrusions on protected privacy interests, for “the Fourth Amendment pro-' vides protection to the owner of every container that conceals" its contents from plain view.” United States v. Ross, 456 U. S. 798, 822-823 (1982). A search of a child’s person or of' a closed purse or other bag carried on her person,5 no less *338than a similar search carried out on an adult, is undoubtedly a severe violation of subjective expectations of privacy.

. Of course, the Fourth Amendment does not protect subjective expectations of privacy that are unreasonable or otherwise “illegitimate.” See, e. g., Hudson v. Palmer, 468 U. S. 517 (1984); Rawlings v. Kentucky, 448 U. S. 98 (1980). To receive the protection of the Fourth Amendment, an expectation of privacy must be one that society is “prepared to recognize as legitimate.” Hudson v. Palmer, supra, at 526. The State of New Jersey has argued that because of the pervasive supervision to which children in the schools are necessarily subject, a child has virtually no legitimate expectation of privacy in articles of personal property “unnecessarily” carried into a school. This argument has two factual premises: (1) the fundamental incompatibility of expectations of privacy with the maintenance of a sound educational environment; and (2) the minimal interest of the child in bringing any items of personal property into the school. Both premises are severely flawed.

Although this Court may take notice of the difficulty of maintaining discipline in the public schools today, the situation is not so dire that students in the schools may claim no legitimate expectations of privacy. We have recently recognized that the need to maintain order in a prison is such that prisoners retain no legitimate expectations of privacy in their cells, but it goes almost without saying that “[tjhe prisoner and the schoolchild stand in wholly different circumstances, separated by the harsh facts of criminal conviction and incarceration.” Ingraham v. Wright, supra, at 669. We are not *339yet ready to hold that the schools and the prisons need be equated for purposes of the Fourth Amendment.

Nor does the State’s suggestion that children have no legitimate need to bring personal property into the schools seem well anchored in reality. Students at a minimum must bring to school not only the supplies needed for their studies, but also keys, money, and the necessaries of personal hygiene and grooming. In addition, students may carry on their persons or in purses or wallets such nondisruptive yet highly personal items as photographs, letters, and diaries. Finally, students may have perfectly legitimate reasons to carry with them articles of property needed in connection with extracurricular or recreational activities. In short, schoolchildren may find it necessary to carry with them a variety of legitimate, noncontraband items, and there is no reason to conclude that they have necessarily waived all rights to privacy in such items merely by bringing them onto school grounds.

Against the child’s interest in privacy must be set the substantial interest of teachers and administrators in maintaining discipline in the classroom and on school grounds. Maintaining order in the classroom has never been easy, but in recent years, school disorder has often taken particularly ugly forms: drug use and violent crime in the schools have become major social problems. See generally 1 NIE, U. S. Dept, of Health, Education and Welfare, Violent Schools— Safe Schools: The Safe School Study Report to the Congress (1978). Even in schools that have been spared the most severe disciplinary problems, the preservation of order and a proper educational environment requires close supervision of schoolchildren, as well as the enforcement of rules against conduct that would be perfectly permissible if undertaken by an adult. “Events calling for discipline are frequent occurrences and sometimes require immediate, effective action.” Goss v. Lopez, 419 U. S., at 580. Accordingly, we have rec*340ognized that maintaining security and order in the schools requires a certain degree of flexibility in school disciplinary procedures, and we have respected the value of preserving the informality of the student-teacher relationship. See id., at 582-583; Ingraham v. Wright, 430 U. S., at 680-682.

How, then, should we strike the balance between the schoolchild’s legitimate expectations of privacy and the school’s equally legitimate need to maintain an environment in which learning can take place? It is evident that the school setting requires some easing of the restrictions to which searches by public authorities are ordinarily subject. The warrant requirement, in particular, is unsuited to the school environment: requiring a teacher to obtain a warrant before searching a child suspected of an infraction of school rules (or of the criminal law) would unduly interfere with the maintenance of the swift and informal disciplinary procedures needed in the schools. Just as we have in other cases dispensed with the warrant requirement when “the burden of obtaining a warrant is likely to frustrate the governmental purpose behind the search,” Camara v. Municipal Court, 387 U. S., at 532-533, we hold today that school officials need not obtain a warrant before searching a student who is under their authority.

The school setting also requires some modification of the level of suspicion of illicit activity needed to justify a search. Ordinarily, a search — even one that may permissibly be carried out without a warrant — must be based upon “probable cause” to believe that a violation of the law has occurred. See, e. g., Almeida-Sanchez v. United States, 413 U. S. 266, 273 (1973); Sibron v. New York, 392 U. S. 40, 62-66 (1968). However, “probable cause” is not an irreducible requirement of a valid search. The fundamental command of the Fourth Amendment is that searches and seizures be reasonable, and although “both the concept of probable cause and the requirement of a warrant bear on the reasonableness of a search, . . . in certain limited circumstances neither is required.” Almeida-Sanchez v. United States, supra, at 277 (Powell, *341J., concurring). Thus, we have in a number of cases recognized the legality of searches and seizures based on suspicions that, although “reasonable,” do not rise to the level of probable cause. See, e. g., Terry v. Ohio, 392 U. S. 1 (1968); United States v. Brignoni-Ponce, 422 U. S. 873, 881 (1975); Delaware v. Prouse, 440 U. S. 648, 654-655 (1979); United States v. Martinez-Fuerte, 428 U. S. 543 (1976); cf. Camara v. Municipal Court, supra, at 534-539. Where a careful balancing of governmental and private interests suggests that the public interest is best served by a Fourth Amendment standard of reasonableness that stops short of probable cause, we have not hesitated to adopt such a standard.

We join the majority of courts that have examined this issue6 in concluding that the accommodation of the privacy interests of schoolchildren with the substantial need of teachers and administrators for freedom to maintain order in the schools does not require strict adherence to the requirement that searches be based on probable cause to believe that the subject of the search has violated or is violating the law. Rather, the legality of a search of a student should depend simply on the reasonableness, under all the circumstances, of the search. Determining the reasonableness of any search involves a twofold inquiry: first, one must consider “whether the . . . action was justified at its inception,” Terry v. Ohio, 392 U. S., at 20; second, one must determine whether the search as actually conducted “was reasonably related in scope to the circumstances which justified the interference in the first place,” ibid. Under ordinary circumstances, a search of a student by a teacher or other school official7 will be *342“justified at its inception” when there are reasonable grounds for suspecting that the search will turn up evidence that the student has violated or is violating either the law or the rules of the school.8 Such a search will be permissible in its scope when the measures adopted are reasonably related to the objectives of the search and not excessively intrusive in light of the age and sex of the student and the nature of the infraction.9

This standard will, we trust, neither unduly burden the efforts of school authorities to maintain order in their schools *343nor authorize unrestrained intrusions upon the privacy of schoolchildren. By focusing attention on the question of reasonableness, the standard will spare teachers and school administrators the necessity of schooling themselves in the niceties of probable cause and permit them to regulate their conduct according to the dictates of reason and common sense. At the same time, the reasonableness standard should ensure that the interests of students will be invaded no more than is necessary to achieve the legitimate end of preserving order in the schools.

IV

There remains the question of the legality of the search in this case. We recognize that the “reasonable grounds” standard applied by the New Jersey Supreme Court in its consideration of this question is not substantially different from the standard that we have adopted today. Nonetheless, we believe that the New Jersey court’s application of that standard to strike down the search of T. L. O.’s purse reflects a somewhat crabbed notion of reasonableness. Our review of the facts surrounding the search leads us to conclude that the search was in no sense unreasonable for Fourth Amendment purposes.10

The incident that gave rise to this case actually involved two separate searches, with the first — the search for cigarettes — providing the suspicion that gave rise to the sec*344ond — the search for marihuana. Although it is the fruits of the second search that are at issue here, the validity of the search for marihuana must depend on the reasonableness of the initial search for cigarettes, as there would have been no reason to suspect that T. L. O. possessed marihuana had the first search not taken place. Accordingly, it is to the search for cigarettes that we first turn our attention.

The New Jersey Supreme Court pointed to two grounds for its holding that the search for cigarettes was unreasonable. First, the court observed that possession of cigarettes was not in itself illegal or a violation of school rules. Because the contents of T. L. O.’s purse would therefore have “no direct bearing on the infraction” of which she was accused (smoking in a lavatory where smoking was prohibited), there was no reason to search her purse.11 Second, even assuming that a search of T. L. O.’s purse might under some circumstances be reasonable in light of the accusation made against T. L. 0., the New Jersey court concluded that Mr. Choplick in this particular case had no reasonable grounds to suspect that T. L. O. had cigarettes in her purse. At best, accord*345ing to the court, Mr. Chopliek had “a good hunch.” 94 N. J., at 347, 463 A. 2d, at 942.

Both these conclusions are implausible. T. L. O. had been accused of smoking, and had denied the accusation in the strongest possible terms when she stated that she did not smoke at all. Surely it cannot be said that under these circumstances, T. L. O.’s possession of cigarettes would be irrelevant to the charges against her or to her response to those charges. T. L. O.’s possession of cigarettes, once it was discovered, would both corroborate the report that she had been smoking and undermine the credibility of her defense to the charge of smoking. To be sure, the discovery of the cigarettes would not prove that T. L. O. had been smoking in the lavatory; nor would it, strictly speaking, necessarily be inconsistent with her claim that she did not smoke at all. But it is universally recognized that evidence, to be relevant to an inquiry, need not conclusively prove the ultimate fact in issue, but only have “any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.” Fed. Rule Evid. 401. The relevance of T. L. O.’s possession of cigarettes to the question whether she had been smoking and to the credibility of her denial that she smoked supplied the necessary “nexus” between the item searched for and the infraction under investigation. See Warden v. Hayden, 387 U. S. 294, 306-307 (1967). Thus, if Mr. Chopliek in fact had a reasonable suspicion that T. L. O. had cigarettes in her purse, the search was justified despite the fact that the cigarettes, if found, would constitute “mere evidence” of a violation. Ibid.

Of course, the New Jersey Supreme Court also held that Mr. Chopliek had no reasonable suspicion that the purse would contain cigarettes. This conclusion is puzzling. A teacher had reported that T. L. O. was smoking in the lavatory. Certainly this report gave Mr. Chopliek reason to suspect that T. L. O. was carrying cigarettes with her; and *346if she did have cigarettes, her purse was the obvious place in which to find them. Mr. Choplick’s suspicion that there were cigarettes in the purse was not an “inchoate and un-particularized suspicion or ‘hunch,’” Terry v. Ohio, 392 U. S., at 27; rather, it was the sort of “common-sense conclusio[n] about human behavior” upon which “practical people” — including government officials — are entitled to rely. United States v. Cortez, 449 U. S. 411, 418 (1981). Of course, even if the teacher’s report were true, T. L. O. might not have had a pack of cigarettes with her; she might have borrowed a cigarette from someone else or have been sharing a cigarette with another student. But the requirement of reasonable suspicion is not a requirement of absolute certainty: “sufficient probability, not certainty, is the touchstone of reasonableness under the Fourth Amendment. ...” Hill v. California, 401 U. S. 797, 804 (1971). Because the hypothesis that T. L. O. was carrying cigarettes in her purse was itself not unreasonable, it is irrelevant that other hypotheses were also consistent with the teacher’s accusation. Accordingly, it cannot be said that Mr. Choplick acted unreasonably when he examined T. L. O.’s purse to see if it contained cigarettes.12

*347Our conclusion that Mr. Choplick’s decision to open T. L. O.’s purse was reasonable brings us to the question of the further search for marihuana once the pack of cigarettes was located. The suspicion upon which the search for marihuana was founded was provided when Mr. Choplick observed a package of rolling papers in the purse as he removed the pack of cigarettes. Although T. L. O. does not dispute the reasonableness of Mr. Choplick’s belief that the rolling papers indicated the presence of marihuana, she does contend that the scope of the search Mr. Choplick conducted exceeded permissible bounds when he seized and read certain letters that implicated T. L. O. in drug dealing. This argument, too, is unpersuasive. The discovery of the rolling papers concededly gave rise to a reasonable suspicion that T. L. O. was carrying marihuana as well as cigarettes in her purse. This suspicion justified further exploration of T. L. O.’s purse, which turned up more evidence of drug-related activities: a pipe, a number of plastic bags of the type commonly used to store marihuana, a small quantity of marihuana, and a fairly substantial amount of money. Under these circumstances, it was not unreasonable to extend the search to a separate zippered compartment of the purse; and when a search of that compartment revealed an index card containing a list of “people who owe me money” as well as two letters, the inference that T. L. O. was involved in marihuana trafficking was substantial enough to justify Mr. Choplick in examining the letters to determine whether they contained any further evidence. In short, we cannot conclude that the search for marihuana was unreasonable in any respect.

Because the search resulting in the discovery of the evidence of marihuana dealing by T. L. O. was reasonable, the New Jersey Supreme Court’s decision to exclude that evi*348dence from T. L. O.’s juvenile delinquency proceedings on Fourth Amendment grounds was erroneous. Accordingly, the judgment of the Supreme Court of New Jersey is

Reversed.

Justice Powell,

with whom Justice O’Connor joins,

concurring.

I agree with the Court’s decision, and generally with its opinion. I would place greater emphasis, however, on the special characteristics of elementary and secondary schools that make it unnecessary to afford students the same constitutional protections granted adults and juveniles in a nonschool setting.

In any realistic sense, students within the school environment have a lesser expectation of privacy than members of the population generally. They spend the school hours in close association with each other, both in the classroom and during recreation periods. The students in a particular class often know each other and their teachers quite well. Of necessity, teachers have a degree of familiarity with, and authority over, their students that is unparalleled except perhaps in the relationship between parent and child. It is simply unrealistic to think that students have the same subjective expectation of privacy as the population generally. But for purposes of deciding this case, I can assume that children in school — no less than adults — have privacy interests that society is prepared to recognize as legitimate.

However one may characterize their privacy expectations, students properly are afforded some constitutional protections. In an often quoted statement, the Court said that students do not “shed their constitutional rights ... at the schoolhouse gate.” Tinker v. Des Moines Independent Community School District, 393 U. S. 503, 506 (1969). The Court also has “emphasized the need for affirming the comprehensive authority of the states and of school officials . . . *349to prescribe and control conduct in the schools.” Id., at 507. See also Epperson v. Arkansas, 393 U. S. 97, 104 (1968). The Court has balanced the interests of the student against the school officials’ need to maintain discipline by recognizing qualitative differences between the constitutional remedies to which students and adults are entitled.

In Goss v. Lopez, 419 U. S. 565 (1975), the Court recognized a constitutional right to due process, and yet was careful to limit the exercise of this right by a student who challenged a disciplinary suspension. The only process found to be “due” was notice and a hearing described as “rudimentary”; it amounted to no more than “the disciplinarian . . . informally discussing] the alleged misconduct with the student minutes after it has occurred.” Id., at 581-582. In Ingraham v. Wright, 430 U. S. 651 (1977), we declined to extend the Eighth Amendment to prohibit the use of corporal punishment of schoolchildren as authorized by Florida law. We emphasized in that opinion that familiar constraints in the school, and also in the community, provide substantial protection against the violation of constitutional rights by school authorities. “[A]t the end of the school day, the child is invariably free to return home. Even while at school, the child brings with him the support of family and friends and is rarely apart from teachers and other pupils who may witness and protest any instances of mistreatment.” Id., at 670. The Ingraham Court further pointed out that the “openness of the public school and its supervision by the community afford significant safeguards” against the violation of constitutional rights. Ibid.

The special relationship between teacher and student also distinguishes the setting within which schoolchildren operate. Law enforcement officers function as adversaries of criminal suspects. These officers have the responsibility to investigate criminal activity, to locate and arrest those who violate our laws, and to facilitate the charging and bringing of such persons to trial. Rarely does this type of adversarial *350relationship exist between school authorities and pupils.1 Instead,'there is a commonality of interests between teachers and their pupils. The attitude of the typical teacher is one of personal responsibility for the student’s welfare as well as for his education.

The primary duty of school officials and teachers, as the Court states, is the education and training of young people. A State has a compelling interest in assuring that the schools meet this responsibility. Without first establishing discipline and maintaining order, teachers cannot begin to educate their students. And apart from education, the school has the obligation to protect pupils from mistreatment by other children, and also to protect teachers themselves from violence by the few students whose conduct in recent years has prompted national concern. For me, it would be unreasonable and at odds with history to argue that the full panoply of constitutional rules applies with the same force and effect in the schoolhouse as it does in the enforcement of criminal laws.2

In sum, although I join the Court’s opinion and its holding,3 my emphasis is somewhat different.

*351Justice Blackmun,

concurring in the judgment.

I join the judgment of the Court and agree with much that is said in its opinion. I write separately, however, because I believe the Court omits a crucial step in its analysis of whether a school search must be based upon probable cause. The Court correctly states that we have recognized limited exceptions to the probable-cause requirement “[w]here a careful balancing of governmental and private interests suggests that the public interest is best served” by a lesser standard. Ante, at 341. I believe that we have used such a balancing test, rather than strictly applying the Fourth Amendment’s Warrant and Probable-Cause Clause, only when we were confronted with “a special law enforcement need for greater flexibility.” Florida v. Royer, 460 U. S. 491, 514 (1983) (Blackmun, J., dissenting). I pointed out in United States v. Place, 462 U. S. 696 (1983):

“While the Fourth Amendment speaks in terms of freedom from unreasonable [searches], the Amendment does not leave the reasonableness of most [searches] to the judgment of courts or government officers; the Framers of the Amendment balanced the interests involved and decided that a [search] is reasonable only if supported by a judicial warrant based on probable cause. See Texas v. Brown, 460 U. S. 730, 744-745 (1983) (Powell, J., concurring); United States v. Rabinomtz, 339 U. S. 56, 70 (1950) (Frankfurter, J., dissenting).” Id., at 722 (opinion concurring in judgment).

See also Dunaway v. New York, 442 U. S. 200, 213-214 (1979); United States v. United States District Court, 407 U. S. 297, 315-316 (1972). Only in those exceptional circumstances in which special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable, is a court entitled to substitute its balancing of interests for that of the Framers.

*352Thus, for example, in determining that police can conduct a limited “stop and frisk” upon less than probable cause, this Court relied upon the fact that “as a practical matter” the stop and frisk could not be subjected to a warrant and probable-cause requirement, because a law enforcement officer must be able to take immediate steps to assure himself that the person he has stopped to question is not armed with a weapon that could be used against him. Terry v. Ohio, 392 U. S. 1, 20-21, 23-24 (1968). Similarly, this Court’s holding that a roving Border Patrol may stop a car and briefly question its occupants upon less than probable cause was based in part upon “the absence of practical alternatives for policing the border.” United States v. Brignoni-Ponce, 422 U. S. 873, 881 (1975). See also Michigan v. Long, 463 U. S. 1032, 1049, n. 14 (1983); United States v. Martinez-Fuerte, 428 U. S. 543, 557 (1976); Camara v. Municipal Court, 387 U. S. 523, 537 (1967).

The Court’s implication that the balancing test is the rule rather than the exception is troubling for me because it is unnecessary in this case. The elementary and secondary school setting presents a special need for flexibility justifying a departure from the balance struck by the Framers. As Justice Powell notes, “[without first establishing discipline and maintaining order, teachers cannot begin to educate their students.” Ante, at 350. Maintaining order in the classroom can be a difficult task. A single teacher often must watch over a large number of students, and, as any parent knows, children at certain ages are inclined to test the outer boundaries of acceptable conduct and to imitate the misbehavior of a peer if that misbehavior is not dealt with quickly. Every adult remembers from his own schooldays the havoc a water pistol or peashooter can wreak until it is taken away. Thus, the Court has recognized that “[ejvents calling for discipline are frequent occurrences and sometimes require immediate, effective action.” Goss v. Lopez, 419 U. S. 565, 580 (1975). Indeed, because drug use and possession of weapons have become increasingly common *353among young people, an immediate response frequently is required not just to maintain an environment conducive to learning, but to protect the very safety of students and school personnel.

Such immediate action obviously would not be possible if a teacher were required to secure a warrant before searching a student. Nor would it be possible if a teacher could not conduct a necessary search until the teacher thought there was probable cause for the search. A teacher has neither the training nor the day-to-day experience in the complexities of probable cause that a law enforcement officer possesses, and is ill-equipped to make a quick judgment about the existence of probable cause. The time required for a teacher to ask the questions or make the observations that are necessary to turn reasonable grounds into probable cause is time during which the teacher, and other students, are diverted from the essential task of education. A teacher’s focus is, and should be, on teaching and helping students, rather than on developing evidence against a particular troublemaker.

Education “is perhaps the most important function” of government, Brown v. Board of Education, 347 U. S. 483, 493 (1954), and government has a heightened obligation to safeguard students whom it compels to attend school. The special need for an immediate response to behavior that threatens either the safety of schoolchildren and teachers or the educational process itself justifies the Court in excepting school searches from the warrant and probable-cause requirement, and in applying a standard determined by balancing the relevant interests. I agree with the standard the Court has announced, and with its application of the standard to the facts of this case. I therefore concur in its judgment.

Justice Brennan,

with whom Justice Marshall joins,

concurring in part and dissenting in part.

I fully agree with Part II of the Court’s opinion. Teachers, like all other government officials, must conform their *354conduct to the Fourth Amendment’s protections of personal privacy and personal security. As Justice Stevens points out, post, at 373-374, 385-386, this principle is of particular importance when applied to schoolteachers, for children learn as much by example as by exposition. It would be incongruous and futile to charge teachers with the task of embuing their students with an understanding of our system of constitutional democracy, while at the same time immunizing those same teachers from the need to respect constitutional protections. See Board of Education v. Pico, 457 U. S. 853, 864-865 (1982) (plurality opinion); West Virginia State Board of Education v. Barnette, 319 U. S. 624, 637 (1943).

I do not, however, otherwise join the Court’s opinion. Today’s decision sanctions school officials to conduct full-scale searches on a “reasonableness” standard whose only definite content is that it is not the same test as the “probable cause” standard found in the text of the Fourth Amendment. In adopting this unclear, unprecedented, and unnecessary departure from generally applicable Fourth Amendment standards, the Court carves out a broad exception to standards that this Court has developed over years of considering Fourth Amendment problems. Its decision is supported neither by precedent nor even by a fair application of the “balancing test” it proclaims in this very opinion.

I

Three basic principles underly this Court’s Fourth Amendment jurisprudence. First, warrantless searches are per se unreasonable, subject only to a few specifically delineated and well-recognized exceptions. See, e. g., Katz v. United States, 389 U. S. 347, 357 (1967); accord, Welsh v. Wisconsin, 466 U. S. 740, 748-749 (1984); United States v. Place, 462 U. S. 696, 701 (1983); Steagald v. United States, 451 U. S. 204, 211-212 (1981); Mincey v. Arizona, 437 U. S. 385 (1978); Terry v. Ohio, 392 U. S. 1, 20 (1968); Johnson v. United States, 333 U. S. 10, 13-14 (1948). Second, full-scale searches — whether conducted in accordance with the war*355rant requirement or pursuant to one of its exceptions — are “reasonable” in Fourth Amendment terms only on a showing of probable cause to believe that a crime has been committed and that evidence of the crime will be found in the place to be searched. Beck v. Ohio, 379 U. S. 89, 91 (1964); Wong Sun v. United States, 371 U. S. 471, 479 (1963); Brinegar v. United States, 338 U. S. 160, 175-176 (1949). Third, categories of intrusions that are substantially less intrusive than full-scale searches or seizures may be justifiable in accordance with a balancing test even absent a warrant or probable cause, provided that the balancing test used gives sufficient weight to the privacy interests that will be infringed. Dunaway v. New York, 442 U. S. 200, 210 (1979); Terry v. Ohio, supra.

Assistant Vice Principal Choplick’s thorough excavation of T. L. O.’s purse was undoubtedly a serious intrusion on her privacy. Unlike the searches in Terry v. Ohio, supra, or Adams v. Williams, 407 U. S. 143 (1972), the search at issue here encompassed a detailed and minute examination of respondent’s pocketbook, in which the contents of private papers and letters were thoroughly scrutinized.1 Wisely, neither petitioner nor the Court today attempts to justify the search of T. L. O.’s pocketbook as a minimally intrusive search in the Terry line. To be faithful to the Court’s settled doctrine, the inquiry therefore must focus on the warrant and probable-cause requirements.

A

I agree that schoolteachers or principals, when not acting as agents of law enforcement authorities, generally may conduct a search of their students’ belongings without first *356obtaining a warrant. To agree with the Court on this point is to say that school searches may justifiably be held to that extent to constitute an exception to the Fourth Amendment’s warrant requirement. Such an exception, however, is not to be justified, as the Court apparently holds, by assessing net social value through application of an unguided “balancing test” in which “the individual’s legitimate expectations of privacy and personal security” are weighed against “the government’s need for effective methods to deal with breaches of public order.” Ante, at 337. The Warrant Clause is something more than an exhortation to this Court to maximize social welfare as we see fit. It requires that the authorities must obtain a warrant before conducting a full-scale search. The undifferentiated governmental interest in law enforcement is insufficient to justify an exception to the warrant requirement. Rather, some special governmental interest beyond the need merely to apprehend lawbreakers is necessary to justify a categorical exception to the warrant requirement. For the most part, special governmental needs sufficient to override the warrant requirement flow from “exigency” — that is, from the press of time that makes obtaining a warrant either impossible or hopelessly infeasible. See United States v. Place, supra, at 701-702; Mincey v. Arizona, supra, at 393-394; Johnson v. United States, supra, at 15. Only after finding an extraordinary governmental interest of this kind do we — or ought we — engage in a balancing test to determine if a warrant should nonetheless be required.2

*357To require a showing of some extraordinary governmental interest before dispensing with the warrant requirement is not to undervalue society’s need to apprehend violators of the criminal law. To be sure, forcing law enforcement personnel to obtain a warrant before engaging in a search will predictably deter the police from conducting some searches that they would otherwise like to conduct. But this is not an unintended result of the Fourth Amendment’s protection of privacy; rather, it is the very purpose for which the Amendment was thought necessary. Only where the governmental interests at stake exceed those implicated in any ordinary law enforcement context — that is, only where there is some extraordinary governmental interest involved — is it legitimate to engage in a balancing test to determine whether a warrant is indeed necessary.

In this case, such extraordinary governmental interests do exist and are sufficient to justify an exception to the warrant requirement. Students are necessarily confined for most of the schoolday in close proximity to each other and to the school staff. I agree with the Court that we can take judicial notice of the serious problems of drugs and violence that plague our schools. As Justice Blackmun notes, teachers must not merely “maintain an environment conducive to learning” among children who “are inclined to test the outer boundaries of acceptable conduct,” but must also “protect the very safety of students and school personnel.” Ante, at 352-353. A teacher or principal could neither carry out essential teaching functions nor adequately protect students’ safety if required to wait for a warrant before conducting a necessary search.

B

I emphatically disagree with the Court’s decision to east aside the constitutional probable-cause standard when assessing the constitutional validity of a schoolhouse search. The Court’s decision jettisons the probable-cause standard— the only standard that finds support in the text of the Fourth *358Amendment — on the basis of its Rohrschach-like “balancing test.” Use of such a “balancing test” to determine the standard for evaluating the validity of a full-scale search represents a sizable innovation in Fourth Amendment analysis. This innovation finds support neither in precedent nor policy and portends a dangerous weakening of the purpose of the Fourth Amendment to protect the privacy and security of our citizens. Moreover, even if this Court’s historic understanding of the Fourth Amendment were mistaken and a balancing test of some kind were appropriate, any such test that gave adequate weight to the privacy and security interests protected by the Fourth Amendment would not reach the preordained result the Court's conclusory analysis reaches today. Therefore, because I believe that the balancing test used by the Court today is flawed both in its inception and in its execution, I respectfully dissent.

1

An unbroken line of cases in this Court have held that probable cause is a prerequisite for a full-scale search. In Carroll v. United States, 267 U. S. 132, 149 (1925), the Court held that “[o]n reason and authority the true rule is that if the search and seizure . . . are made upon probable cause .. . the search and seizure are valid.” Under our past decisions probable cause — which exists where “the facts and circumstances within [the officials’] knowledge and of which they had reasonably trustworthy information [are] sufficient in themselves to warrant a man of reasonable caution in the belief” that a criminal offense had occurred and the evidence would be found in the suspected place, id., at 162 — is the constitutional minimum for justifying a full-scale search, regardless of whether it is conducted pursuant to a warrant or, as in Carroll, within one of the exceptions to the warrant requirement. Henry v. United States, 361 U. S. 98, 104 (1959) (Carroll “merely relaxed the requirements for a warrant on grounds of practicality,” but “did not dispense *359with the need for probable cause”); accord, Chambers v. Maroney, 399 U. S. 42, 51 (1970) (“In enforcing the Fourth Amendment’s prohibition against unreasonable searches and seizures, the Court has insisted upon probable cause as a minimum requirement for a reasonable search permitted by the Constitution”).3

Our holdings that probable cause is a prerequisite to a full-scale search are based on the relationship between the two Clauses of the Fourth Amendment. The first Clause (“The right of the people to be secure in their persons, houses, papers and effects, against unreasonable searches and seizures, shall not be violated . . .”) states the purpose of the Amendment and its coverage. The second Clause (“. . . and no Warrants shall issue but upon probable cause . . .”) gives content to the word “unreasonable” in the first Clause. “For all but . . . narrowly defined intrusions, the requisite ‘balancing’ has been performed in centuries of precedent and is embodied in the principle that seizures are ‘reasonable’ only if supported by probable cause.” Dunaway v. New York, 442 U. S., at 214.

I therefore fully agree with the Court that “the underlying command of the Fourth Amendment is always that searches and seizures be reasonable.” Ante, at 337. But this “underlying command” is not directly interpreted in each category of cases by some amorphous “balancing test.” Rather, the provisions of the Warrant Clause — a warrant and probable cause — provide the yardstick against which official searches *360and seizures are to be measured. The Fourth Amendment neither requires nor authorizes the conceptual free-for-all that ensues when an unguided balancing test is used to assess specific categories of searches. If the search in question is more than a minimally intrusive Terry stop, the constitutional probable-cause standard determines its validity.

To be sure, the Court recognizes that probable cause “ordinarily” is required to justify a full-scale search and that the existence of probable cause “bears on” the validity of the search. Ante, at 340-341. Yet the Court fails to cite any case in which a full-scale intrusion upon privacy interests has been justified on less than probable cause. The line of cases begun by Terry v. Ohio, 392 U. S. 1 (1968), provides no support, for they applied a balancing test only in the context of minimally intrusive searches that served crucial law enforcement interests. The search in Terry itself, for instance, was a “limited search of the outer clothing.” Id., at 30. The type of border stop at issue in United States v. Brignoni-Ponce, 422 U. S. 873, 880 (1975), usually “consume[d] no more than a minute”; the Court explicitly noted that “any further detention . . . must be based on consent or probable cause.” Id., at 882. See also United States v. Hensley, ante, at 224 (momentary stop); United States v. Place, 462 U. S., at 706-707 (brief detention of luggage for canine “sniff”); Pennsylvania v. Mimms, 434 U. S. 106 (1977) (per curiam) (brief frisk after stop for traffic violation); United States v. Martinez-Fuerte, 428 U. S. 543, 560 (1976) (characterizing intrusion as “minimal”); Adams v. Williams, 407 U. S. 143 (1972) (stop and frisk). In short, all of these cases involved “‘seizures’ so substantially less intrusive than arrests that the general rule requiring probable cause to make Fourth Amendment ‘seizures’ reasonable could be replaced by a balancing test.” Dunaway, supra, at 210.

Nor do the “administrative search” cases provide any comfort for the Court. In Camara v. Municipal Court, 387 U. S. 523 (1967), the Court held that the probable-cause standard governed even administrative searches. Although *361the Camara Court recognized that probable-cause standards themselves may have to be somewhat modified to take into account the special nature of administrative searches, the Court did so only after noting that “because [housing code] inspections are neither personal in nature nor aimed at the discovery of evidence of crime, they involve a relatively limited invasion of the urban citizen’s privacy.” Id., at 537. Subsequent administrative search cases have similarly recognized that such searches intrude upon areas whose owners harbor a significantly decreased expectation of privacy, see, e. g., Donovan v. Dewey, 452 U. S. 594, 598-599 (1981), thus circumscribing the injury to Fourth Amendment interests caused by the search.

Considerations of the deepest significance for the freedom of our citizens counsel strict adherence to the principle that no search may be conducted where the official is not in possession of probable cause — that is, where the official does not know of “facts and circumstances [that] warrant a prudent man in believing that the offense has been committed.” Henry v. United States, 361 U. S., at 102; see also id., at 100-101 (discussing history of probable-cause standard). The Fourth Amendment was designed not merely to protect against official intrusions whose social utility was less as measured by some “balancing test” than its intrusion on individual privacy; it was designed in addition to grant the individual a zone of privacy whose protections could be breached only where the “reasonable” requirements of the probable-cause standard were met. Moved by whatever momentary evil has aroused their fears, officials — perhaps even supported by a majority of citizens — may be tempted to conduct searches that sacrifice the liberty of each citizen to assuage the perceived evil.4 But the Fourth Amendment *362rests on the principle that a true balance between the individual and society depends on the recognition of “the right to be let alone — the most comprehensive of rights and the right most valued by civilized men.” Olmstead v. United States, 277 U. S. 438, 478 (1928) (Brandéis, J., dissenting). That right protects the privacy and security of the individual unless the authorities can cross a specific threshold of need, designated by the term “probable cause.” I cannot agree with the Court’s assertions today that a “balancing test” can replace the constitutional threshold with one that is more convenient for those enforcing the laws but less protective of the citizens’ liberty; the Fourth Amendment’s protections should not be defaced by “a balancing process that overwhelms the individual’s protection against unwarranted official intrusion by a governmental interest said to justify the search and seizure.” United States v. Martinez-Fuerte, supra, at 570 (Brennan, J., dissenting).

2

I thus do not accept the majority’s premise that “[t]o hold that the Fourth Amendment applies to searches conducted by school authorities is only to begin the inquiry into the standards governing such searches.” Ante, at 337. For me, the finding that the Fourth Amendment applies, coupled with the observation that what is at issue is a full-scale search, is the end of the inquiry. But even if I believed that a “balancing test” appropriately replaces the judgment of the Framers of the Fourth Amendment, I would nonetheless object to the cursory and shortsighted “test” that the Court employs to justify its predictable weakening of Fourth Amendment protections. In particular, the test employed by the Court vastly overstates the social costs that a probable-cause standard entails and, though it plausibly articulates the serious privacy interests at stake, inexplicably fails to accord them adequate weight in striking the balance.

*363The Court begins to articulate its “balancing test” by-observing that “the government’s need for effective methods to deal with breaches of public order” is to be weighed on one side of the balance. Ibid. Of course, this is not correct. It is not the government’s need for effective enforcement methods that should weigh in the balance, for ordinary Fourth Amendment standards — including probable cause— may well permit methods for maintaining the public order that are perfectly effective. If that were the case, the governmental interest in having effective standards would carry no weight at all as a justification for departing from the probable-cause standard. Rather, it is the costs of applying probable cause as opposed to applying some lesser standard that should be weighed on the government’s side.5

In order to tote up the costs of applying the probable-cause standard, it is thus necessary first to take into account the nature and content of that standard, and the likelihood that it would hamper achievement of the goal — vital not just to “teachers and administrators,” see ante, at 339 — of maintaining an effective educational setting in the public schools. The seminal statement concerning the nature of the probable-cause standard is found in Carroll v. United States, 267 U. S. 132 (1925). Carroll held that law enforcement authorities have probable cause to search where “the facts and circumstances within their knowledge and of which they had reasonably trustworthy information [are] sufficient in themselves to *364warrant a man of reasonable caution in the belief” that a criminal offense had occurred. Id., at 162. In Brinegar v. United States, 338 U. S. 160 (1949), the Court amplified this requirement, holding that probable cause depends upon “the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.” Id., at 175.

Two Terms ago, in Illinois v. Gates, 462 U. S. 213 (1983), this Court expounded at some length its view of the probable-cause standard. Among the adjectives used to describe the standard were “practical,” “fluid,” “flexible,” “easily applied,” and “nontechnical.” See id., at 232, 236, 239. The probable-cause standard was to be seen as a “common-sense” test whose application depended on an evaluation of the “totality of the circumstances.” Id., at 238.

Ignoring what Gates took such great pains to emphasize, the Court today holds that a new “reasonableness” standard is appropriate because it “will spare teachers and school administrators the necessity of schooling themselves in the niceties of probable cause and permit them to regulate their conduct according to the dictates of reason and common sense.” Ante, at 343. I had never thought that our pre-Gates understanding of probable cause defied either reason or common sense. But after Gates, I would have thought that there could be no doubt that this “nontechnical,” “practical,” and “easily applied” concept was eminently serviceable in a context like a school, where teachers require the flexibility to respond quickly and decisively to emergencies.

A consideration of the likely operation of the probable-cause standard reinforces this conclusion. Discussing the issue of school searches, Professor LaFave has noted that the cases that have reached the appellate courts “strongly suggest that in most instances the evidence of wrongdoing prompting teachers or principals to conduct searches is sufficiently detailed and specific to meet the traditional probable cause test.” 3 W. LaFave, Search and Seizure § 10.11, *365pp. 459-460 (1978).6 The problems that have caused this Court difficulty in interpreting the probable-cause standard have largely involved informants, see, e. g., Illinois v. Gates, supra; Spinelli v. United States, 393 U. S. 410 (1969); Aguilar v. Texas, 378 U. S. 108 (1964); Draper v. United States, 358 U. S. 307 (1959). However, three factors make it likely that problems involving informants will not make it difficult for teachers and school administrators to make probable-cause decisions. This Court’s decision in Gates applying a “totality of the circumstances” test to determine whether an informant’s tip can constitute probable cause renders the test easy for teachers to apply. The fact that students and teachers interact daily in the school building makes it more likely that teachers will get to know students who supply information; the problem of informants who remain anonymous even to the teachers — and who are therefore unavailable for verification or further questioning — is unlikely to arise. Finally, teachers can observe the behavior of students under suspicion to corroborate any doubtful tips they do receive.

As compared with the relative ease with which teachers can apply the probable-cause standard, the amorphous “reasonableness under all the circumstances” standard freshly coined by the Court today will likely spawn increased litigation and greater uncertainty among teachers and administrators. Of course, as this Court should know, an essential purpose of developing and articulating legal norms is to enable individuals to conform their conduct to those norms. A school system conscientiously attempting to obey the Fourth Amendment’s dictates under a probable-cause standard could, for example, consult decisions and other legal materials and prepare a booklet expounding the rough outlines of the concept. Such a booklet could be distributed to *366teachers to provide them with guidance as to when a search may be lawfully conducted. I cannot but believe that the same school system faced with interpreting what is permitted under the Court’s new “reasonableness” standard would be hopelessly adrift as to when a search may be permissible. The sad result of this uncertainty may well be that some teachers will be reluctant to conduct searches that are fully permissible and even necessary under the constitutional probable-cause standard, while others may intrude arbitrarily and unjustifiably on the privacy of students.7

One further point should be taken into account when considering the desirability of replacing the constitutional probable-cause standard. The question facing the Court is not whether the probable-cause standard should be replaced by a test of “reasonableness under all the circumstances.” Rather, it is whether traditional Fourth Amendment standards should recede before the Court’s new standard. Thus, although the Court today paints with a broad brush and holds its undefined “reasonableness” standard applicable to all school searches, I would approach the question with considerably more reserve. I would not think it necessary to develop a single standard to govern all school searches, any more *367than traditional Fourth Amendment law applies even the probable-cause standard to all searches and seizures. For instance, just as police officers may conduct a brief stop and frisk on something less than probable cause, so too should teachers be permitted the same flexibility. A teacher or administrator who had reasonable suspicion that a student was carrying a gun would no doubt have authority under ordinary Fourth Amendment doctrine to conduct a limited search of the student to determine whether the threat was genuine. The “costs” of applying the traditional probable-cause standard must therefore be discounted by the fact that, where additional flexibility is necessary and where the intrusion is minor, traditional Fourth Amendment jurisprudence itself displaces probable cause when it determines the validity of a search.

A legitimate balancing test whose function was something more substantial than reaching a predetermined conclusion acceptable to this Court’s impressions of what authority teachers need would therefore reach rather a different result than that reached by the Court today. On one side of the balance would be the costs of applying traditional Fourth Amendment standards — the “practical” and “flexible” probable-cause standard where a full-scale intrusion is sought, a lesser standard in situations where the intrusion is much less severe and the need for greater authority compelling. Whatever costs were toted up on this side would have to be discounted by the costs of applying an unprecedented and ill-defined “reasonableness under all the circumstances” test that will leave teachers and administrators uncertain as to their authority and will encourage excessive fact-based litigation.

On the other side of the balance would be the serious privacy interests of the student, interests that the Court admirably articulates in its opinion, ante, at 337-339, but which the Court’s new ambiguous standard places in serious jeopardy. I have no doubt that a fair assessment of the two *368sides of the balance would necessarily reach the same conclusion that, as I have argued above, the Fourth Amendment’s language compels — that school searches like that conducted in this case are valid only if supported by probable cause.

I — { 1 — I

Applying the constitutional probable-cause standard to the facts of this case, I would find that Mr. Choplick’s search violated T. L. O.’s Fourth Amendment rights. After escorting T. L. O. into his private office, Mr. Choplick demanded to see her purse. He then opened the purse to find evidence of whether she had been smoking in the bathroom. When he opened the purse, he discovered the pack of cigarettes. At this point, his search for evidence of the smoking violation was complete.

Mr. Choplick then noticed, below the cigarettes, a pack of cigarette rolling papers. Believing that such papers were “associated,” see ante, at 328, with the use of marihuana, he proceeded to conduct a detailed examination of the contents of her purse, in which he found some marihuana, a pipe, some money, an index card, and some private letters indicating that T. L. O. had sold marihuana to other students. The State sought to introduce this latter material in evidence at a criminal proceeding, and the issue before the Court is whether it should have been suppressed.

On my view of the case, we need not decide whether the initial search conducted by Mr. Choplick — the search for evidence of the smoking violation that was completed when Mr. Choplick found the pack of cigarettes — was valid. For Mr. Choplick at that point did not have probable cause to continue to rummage through T. L. O.’s purse. Mr. Choplick’s suspicion of marihuana possession at this time was based solely on the presence of the package of cigarette papers. The mere presence without more of such a staple item of commerce is insufficient to warrant a person of reasonable caution in inferring both that T. L. O. had violated the law *369by possessing marihuana and that evidence of that violation would be found in her purse. Just as a police officer could not obtain a warrant to search a home based solely on his claim that he had seen a package of cigarette papers in that home, Mr. Choplick was not entitled to search possibly the most private possessions of T. L. O. based on the mere presence of a package of cigarette papers. Therefore, the fruits of this illegal search must be excluded and the judgment of the New Jersey Supreme Court affirmed.

h-H H — H

In the past several Terms, this Court has produced a succession of Fourth Amendment opinions in which “balancing tests” have been applied to resolve various questions concerning the proper scope of official searches. The Court has begun to apply a “balancing test” to determine whether a particular category of searches intrudes upon expectations of privacy that merit Fourth Amendment protection. See Hudson v. Palmer, 468 U. S. 517, 527 (1984) (“Determining whether an expectation of privacy is ‘legitimate’ or ‘reasonable’ necessarily entails a balancing of interests”). It applies a “balancing test” to determine whether a warrant is necessary to conduct a search. See ante, at 340; United States v. Martinez-Fuerte, 428 U. S., at 564-566. In today’s opinion, it employs a “balancing test” to determine what standard should govern the constitutionality of a given category of searches. See ante, at 340-341. Should a search turn out to be unreasonable after application of all of these “balancing tests,” the Court then applies an additional “balancing test” to decide whether the evidence resulting from the search must be excluded. See United States v. Leon, 468 U. S. 897 (1984).

All of these “balancing tests” amount to brief nods by the Court in the direction of a neutral utilitarian calculus while the Court in fact engages in an unanalyzed exercise of judicial will. Perhaps this doctrinally destructive nihilism is merely *370a convenient umbrella under which a majority that cannot agree on a genuine rationale can conceal its differences. Compare ante, p. 327 (White, J., delivering the opinion of the Court), with ante, p. 348 (Powell, J., joined by O’Connor, J., concurring), and ante, p. 351 (Blackmun, J., concurring in judgment). And it may be that the real force underlying today’s decision is the belief that the Court purports to reject — the belief that the unique role served by the schools justifies an exception to the Fourth Amendment on their behalf. If so, the methodology of today’s decision may turn out to have as little influence in future cases as will its result, and the Court’s departure from traditional Fourth Amendment doctrine will be confined to the schools.

On my view, the presence of the word “unreasonable” in the text of the Fourth Amendment does not grant a shifting majority of this Court the authority to answer all Fourth Amendment questions by consulting its momentary vision of the social good. Full-scale searches unaccompanied by probable cause violate the Fourth Amendment. I do not pretend that our traditional Fourth Amendment doctrine automatically answers all of the difficult legal questions that occasionally arise. I do contend, however, that this Court has an obligation to provide some coherent framework to resolve such questions on the basis of more than a conclusory recitation of the results of a “balancing test.” The Fourth Amendment itself supplies that framework and, because the Court today fails to heed its message, I must respectfully dissent.

Justice Stevens,

with whom Justice Marshall joins, and with whom Justice Brennan joins as to Part I,

concurring in part and dissenting in part.

Assistant Vice Principal Choplick searched T. L. O.’s purse for evidence that she was smoking in the girls’ restroom. Because T. L. O.’s suspected misconduct was not illegal and did not pose a serious threat to school discipline, the New Jersey Supreme Court held that Choplick’s search *371of her purse was an unreasonable invasion of her privacy and that the evidence which he seized could not be used against her in criminal proceedings. The New Jersey court’s holding was a careful response to the case it was required to decide.

The State of New Jersey sought review in this Court, first arguing that the exclusionary rule is wholly inapplicable to searches conducted by school officials, and then contending that the Fourth Amendment itself provides no protection at all to the student’s privacy. The Court has accepted neither of these frontal assaults on the Fourth Amendment. It has, however, seized upon this “no smoking” case to announce “the proper standard” that should govern searches by school officials who are confronted with disciplinary problems far more severe than smoking in the restroom. Although I join Part II of the Court’s opinion, I continue to believe that the Court has unnecessarily and inappropriately reached out to decide a constitutional question. See 468 U. S. 1214 (1984) (Stevens, J., dissenting from reargument order). More importantly, I fear that the concerns that motivated the Court’s activism have produced a holding that will permit school administrators to search students suspected of violating only the most trivial school regulations and guidelines for behavior.

I

The question the Court decides today — whether Mr. Chop-lick’s search of T. L. O.’s purse violated the Fourth Amendment — was not raised by the State’s petition for writ of certiorari. That petition only raised one question: “Whether the Fourth Amendment’s exclusionary rule applies to searches made by public school officials and teachers in school.”1 The State quite properly declined to submit the former question because “[it] did not wish to present what might appear to be solely a factual dispute to this Court.”2 *372Since this Court has twice had the threshold question argued, I believe that it should expressly consider the merits of the New Jersey Supreme Court’s ruling that the exclusionary rule applies.

The New Jersey Supreme Court’s holding on this question is plainly correct. As the state court noted, this case does not involve the use of evidence in a school disciplinary proceeding; the juvenile proceedings brought against T. L. O. involved a charge that would have been a criminal offense if committed by an adult.3 Accordingly, the exclusionary rule issue decided by that court and later presented to this Court concerned only the use in a criminal proceeding of evidence obtained in a search conducted by a public school administrator.

Having confined the issue to the law enforcement context, the New Jersey court then reasoned that this Court’s cases have made it quite clear that the exclusionary rule is equally applicable “whether the public official who illegally obtained the evidence was a municipal inspector, See v. Seattle 387 U. S. 541 [1967]; Camara [v. Municipal Court,] 387 U. S. 523 [1967]; a firefighter, Michigan v. Tyler, 436 U. S. 499, 506 [1978]; or a school administrator or law enforcement official.”4 It correctly concluded “that if an official search violates constitutional rights, the evidence is not admissible in criminal proceedings.”5

When a defendant in a criminal proceeding alleges that she was the victim of an illegal search by a school administrator, the application of the exclusionary rule is a simple corollary of the principle that “all evidence obtained by searches and seizures in violation of the Constitution is, by that same authority, inadmissible in a state court.” Mapp v. Ohio, 367 U. S. 643, 655 (1961). The practical basis for this principle is, in part, its deterrent effect, see id., at 656, and as a general *373matter it is tolerably clear to me, as it has been to the Court, that the existence of an exclusionary remedy does deter the authorities from violating the Fourth Amendment by sharply reducing their incentive to do so.6 In the case of evidence obtained in school searches, the “overall educative effect”7 of the exclusionary rule adds important symbolic force to this utilitarian judgment.

Justice Brandéis was both a great student and a great teacher. It was he who wrote:

“Our Government is the potent, the omnipresent teacher. For good or for ill, it teaches the whole people by its example. Crime is contagious. If the Government becomes a lawbreaker, it breeds contempt for. law; it invites every man to become a law unto himself; it invites anarchy.” Olmstead v. United States, 277 U. S. 438, 485 (1928) (dissenting opinion).

Those of us who revere the flag and the ideals for which it stands believe in the power of symbols. We cannot ignore that rules of law also have a symbolic power that may vastly exceed their utility.

Schools are places where we inculcate the values essential to the meaningful exercise of rights and responsibilities by a self-governing citizenry.8 If the Nation’s students can be convicted through the use of arbitrary methods destructive of personal liberty, they cannot help but feel that they have *374been dealt with unfairly.9 The application of the exclusionary rule in criminal proceedings arising from illegal school searches makes an important statement to young people that “our society attaches serious consequences to a violation of constitutional rights,”10 and that this is a principle of “liberty and justice for all.”11

Thus, the simple and correct answer to the question presented by the State’s petition for certiorari would have required affirmance of a state court’s judgment suppressing evidence. That result would have been dramatically out of character for a Court that not only grants prosecutors relief from suppression orders with distressing regularity,12 but *375also is prone to rely on grounds not advanced by the parties in order to protect evidence from exclusion.13 In characteristic disregard of the doctrine of judicial restraint, the Court avoided that result in this case by ordering reargument and directing the parties to address a constitutional question that the parties, with good reason, had not asked the Court to decide. Because judicial activism undermines the Court’s power to perform its central mission in a legitimate way, I dissented from the reargument order. See 468 U. S. 1214 (1984). I have not modified the views expressed in that dissent, but since the majority has brought the question before us, I shall explain why I believe the Court has misapplied the standard of reasonableness embodied in the Fourth Amendment.

HH H-t

The search of a young woman’s purse by a school administrator is a serious invasion of her legitimate expectations of privacy. A purse “is a common repository for one’s personal effects and therefore is inevitably associated with the expectation of privacy.” Arkansas v. Sanders, 442 U. S. 753, 762 (1979). Although such expectations must sometimes yield to the legitimate requirements of government, in assessing the constitutionality of a warrantless search, our decision must be guided by the language of the Fourth Amendment: “The right of the people to be secure in their persons, houses, *376papers and effects, against unreasonable searches and seizures, shall not be violated . . . In order to evaluate the reasonableness of such searches, “it is necessary ‘first to focus upon the governmental interest which allegedly justifies official intrusion upon the constitutionally protected interests of the private citizen/ for there is ‘no ready test for determining reasonableness other than by balancing the need to search [or seize] against the invasion which the search [or seizure] entails.’” Terry v. Ohio, 392 U. S. 1, 20-21 (1968) (quoting Camara v. Municipal Court, 387 U. S. 523, 528, 534-537, (1967)).14

The “limited search for weapons” in Terry was justified by the “immediate interest of the police officer in taking steps to assure himself that the person with whom he is dealing is not armed with a weapon that could unexpectedly and fatally be used against him.” 392 U. S., at 23, 25. When viewed from the institutional perspective, “the substantial need of teachers and administrators for freedom to maintain order in the schools,” ante, at 341 (majority opinion), is no less acute. Violent, unlawful, or seriously disruptive conduct is fundamentally inconsistent with the principal function of teaching institutions which is to educate young people and prepare them for citizenship.15 When such conduct occurs amidst a sizable group of impressionable young people, it creates an explosive atmosphere that requires a prompt and effective response.

Thus, warrantless searches of students by school administrators are reasonable when undertaken for those purposes. *377But the majority’s statement of the standard for evaluating the reasonableness of such searches is not suitably adapted to that end. The majority holds that “a search of a student by a teacher or other school official will be ‘justified at its inception’ when there are reasonable grounds for suspecting that the search will turn up evidence that the student has violated or is violating either the law or the rules of the school” Ante, at 341-342. This standard will permit teachers and school administrators to search students when they suspect that the search will reveal evidence of even the most trivial school regulation or precatory guideline for student behavior. The Court’s standard for deciding whether a search is justified “at its inception” treats all violations of the rules of the school as though they were fungible. For the Court, a search for curlers and sunglasses in order to enforce the school dress code16 is apparently just as important as a search for evidence of heroin addiction or violent gang activity.

The majority, however, does not contend that school administrators have a compelling need to search students in *378order.to achieve optimum enforcement of minor school regulations.17 To the contrary, when minor violations are involved, there is every indication that the informal school disciplinary process, with only minimum requirements of due process,18 can function effectively without the power to search for enough evidence to prove a criminal case. In arguing that teachers and school administrators need the power to search students based on a lessened standard, the United States as amicus curiae relies heavily on empirical evidence of a contemporary crisis of violence and unlawful behavior that is seriously undermining the process of education in American schools.19 A standard better attuned to this concern would permit teachers and school administrators to search a student when they have reason to believe that the search will uncover evidence that the student is violating the law or engaging in conduct that is seriously disruptive of school order, or the educational process.

This standard is properly directed at “[t]he sole justification for the [warrantless] search.”20 In addition, a standard *379that varies the extent of the permissible intrusion with the gravity of the suspected offense is also more consistent with common-law experience and this Court’s precedent. Criminal law has traditionally recognized a distinction between essentially regulatory offenses and serious violations of the peace, and graduated the response of the criminal justice system depending on the character of the violation.21 The application of a similar distinction in evaluating the reasonableness of warrantless searches and seizures “is not a novel idea.” Welsh v. Wisconsin, 466 U. S. 740, 750 (1984).22

In Welsh, police officers arrived at the scene of a traffic accident and obtained information indicating that the driver of the automobile involved was guilty of a first offense of *380driving while intoxicated — a civil violation with a maximum fine of $200. The driver had left the scene of the accident, and the officers followed the suspect to his home where they arrested him without a warrant. Absent exigent circumstances, the warrantless invasion of the home was a clear violation of Payton v. New York, 445 U. S. 573 (1980). In holding that the warrantless arrest for the “noncriminal, traffic offense” in Welsh was unconstitutional, the Court noted that “application of the exigent-circumstances exception in the context of a home entry should rarely be sanctioned when there is probable cause to believe that only a minor offense . . . has been committed.” 466 U. S., at 753.

. . . The logic of distinguishing between minor and serious offenses in evaluating the reasonableness of school searches is almost too clear for argument. In order to justify the serious intrusion on the persons and privacy of young people that New Jersey asks this Court to approve, the State must identify “some real immediate and serious consequences.” McDonald v. United States, 335 U. S. 451, 460 (1948) (Jackson, J., concurring, joined by Frankfurter, J.).23 While school administrators have entirely legitimate reasons for adopting school regulations and guidelines for student behavior, the authorization of searches to enforce them “displays a shocking lack of all sense of proportion.” Id., 459.24

*381The majority offers weak deference to these principles of balance and decency by announcing that school searches will only be reasonable in scope “when the measures adopted are reasonably related to the objectives of the search and not excessively intrusive in light of the age and sex of the student and the nature of the infraction” Ante, at 342 (emphasis added). The majority offers no explanation why a two-part standard is necessary to evaluate the reasonableness of the ordinary school search. Significantly, in the balance of its opinion the Court pretermits any discussion of the nature of T. L. O.’s infraction of the “no smoking” rule.

The “rider” to the Court’s standard for evaluating the reasonableness of the initial intrusion apparently is the Court’s perception that its standard is overly generous and does not, by itself, achieve a fair balance between the administrator’s right to search and the student’s reasonable expectations of privacy. The Court’s standard for evaluating the “scope” of reasonable school searches is obviously designed to prohibit physically intrusive searches of students by persons of the opposite sex for relatively minor offenses. The Court’s effort to establish a standard that is, at once, clear enough to allow searches to be upheld in nearly every case, and flexible enough to prohibit obviously unreasonable intrusions of young adults’ privacy only creates uncertainty in the extent of its resolve to prohibit the latter. Moreover, the majority’s application of its standard in this case — to permit a male administrator to rummage through the purse of a female high school student in order to obtain evidence that she was smok*382ing in a bathroom — raises grave doubts in my mind whether its effort will be effective.25 Unlike the Court, I believe the nature of the suspected infraction is a matter of first importance in deciding whether any invasion of privacy is permissible.

Ill

The Court embraces the standard applied by the New Jersey Supreme Court as equivalent to-its own, and then deprecates the state court’s application of the standard as reflecting “a somewhat crabbed notion of reasonableness.” Ante, at 343. There is no mystery, however, in the state court’s finding that the search in this case was unconstitutional; the decision below was not based on a manipulation of reasonable suspicion, but on the trivial character of the activity that promoted the official search. The New Jersey Supreme Court wrote:

“We are satisfied that when a school official has reasonable grounds to believe that a student possesses evidence of illegal activity or activity that would interfere with school discipline and order, the school official has the right to conduct a reasonable search for such evidence.

“In determining whether the school official has reasonable grounds, courts should consider The child’s age, history, and school record, the prevalence and seriousness of the problem in the school to which the search was *383directed, the exigency to make the search without delay, and the probative value and reliability of the information used as a justification for the search.’”26

The emphasized language in the state court’s opinion focuses on the character of the rule infraction that is to be the object of the search.

In the view of the state court, there is a quite obvious and material difference between a search for evidence relating to violent or disruptive activity, and a search for evidence of a smoking rule violation. This distinction does not imply that a no-smoking rule is a matter of minor importance. Rather, like a rule that prohibits a student from being tardy, its occasional violation in a context that poses no threat of disrupting school order and discipline offers no reason to believe that an immediate search is necessary to avoid unlawful conduct, violence, or a serious impairment of the educational process.

A correct understanding of the New Jersey court’s standard explains why that court concluded in T. L. O.’s case that “the assistant principal did not have reasonable grounds to believe that the student was concealing in her purse evidence of criminal activity or evidence of activity that would seriously interfere with school discipline or order.”27 The importance of the nature of the rule infraction to the New Jersey Supreme Court’s holding is evident from its brief explanation of the principal basis for its decision:

“A student has an expectation of privacy in the contents of her purse. Mere possession of cigarettes did not violate school rule or policy, since the school allowed smoking in designated areas. The contents of the handbag had no direct bearing on the infraction.

“The assistant principal’s desire, legal in itself, to gather evidence to impeach the student’s credibility at a *384hearing on the disciplinary infraction does not validate the search.”28

Like the New Jersey Supreme Court, I would view this case differently if the Assistant Vice Principal had reason to believe T. L. O.’s purse contained evidence of criminal activity, or of an activity that would seriously disrupt school discipline. There was, however, absolutely no basis for any such assumption — not even a “hunch.”

In this case, Mr. Choplick overreacted to what appeared to be nothing more than a minor infraction — a rule prohibiting smoking in the bathroom of the freshmen’s and sophomores’ building.29 It is, of course, true that he actually found evidence of serious wrongdoing by T. L. 0., but no one claims that the prior search may be justified by his unexpected discovery. As far as the smoking infraction is concerned, the search for cigarettes merely tended to corroborate a teacher’s eyewitness account of T. L. O.’s violation of a minor regulation designed to channel student smoking behavior into designated locations. Because this conduct was neither unlawful nor significantly disruptive of school order or the educational process, the invasion of privacy associated with the forcible opening of T. L. O.’s purse was entirely unjustified at its inception.

A review of the sampling of school search cases relied on by the Court demonstrates how different this case is from those *385in which there was indeed a valid justification for intruding on a student’s privacy. In most of them the student was suspected of a criminal violation;30 in the remainder either violence or substantial disruption of school order or the integrity of the academic process was at stake.31 New involved matters as trivial as the no-smoking rule violated by T. L. O.32 The rule the Court adopts today is so open-ended that it may make the Fourth Amendment virtually meaningless in the school context. Although I agree that school administrators must have broad latitude to maintain order and discipline in our classrooms, that authority is not unlimited.

> I — I

The schoolroom is the first opportunity most citizens have to experience the power of government. Through it passes every citizen and public official, from schoolteachers to *386policemen and prison guards. The values they learn there, they take with them in life. One of our most cherished ideals is the one contained in the Fourth Amendment: that the government may not intrude on the personal privacy of its citizens without a warrant or compelling circumstance. The Court’s decision today is a curious moral for the Nation’s youth. Although the search of T. L. O.’s purse does not trouble today’s majority, I submit that we are not dealing with “matters relatively trivial to the welfare of the Nation. There are village tyrants as well as village Hampdens, but none who acts under color of law is beyond reach of the Constitution.” West Virginia State Board of Education v. Barnette, 319 U. S. 624, 638 (1943).

I respectfully dissent.

*606Justice Kennedy

delivered the opinion of the Court.

The Federal Railroad Safety Act of 1970 authorizes the Secretary of Transportation to “prescribe, as necessary, appropriate rules, regulations, orders, and standards for all areas of railroad safety.” 84 Stat. 971, 45 U. S. C. § 431(a). Finding that alcohol and drug abuse by railroad employees poses a serious threat to safety, the Federal Railroad Administration (FRA) has promulgated regulations that mandate blood and urine tests of employees who are involved in certain train accidents. The FRA also has adopted regulations that do not require, but do authorize, railroads to administer breath and urine tests to employees who violate certain safety rules. The question presented by this case is whether these regulations violate the Fourth Amendment.

I

A

The problem of alcohol use on American railroads is as old as the industry itself, and efforts to deter it by carrier rules began at least a century ago. For many years, railroads have prohibited operating employees from possessing alcohol or being intoxicated while on duty and from consuming alcoholic beverages while subject to being called for duty. More recently, these proscriptions have been expanded to forbid possession or use of certain drugs. These restrictions are *607embodied in “Rule G,” an industry-wide operating rule promulgated by the Association of American Railroads, and are enforced, in various formulations, by virtually every railroad in the country. The customary sanction for Rule G violations is dismissal.

In July 1983, the FRA expressed concern that these industry efforts were not adequate to curb alcohol and drug abuse by railroad employees. The FRA pointed to evidence indicating that on-the-job intoxication was a significant problem in the railroad industry.1 The FRA also found, after a review of accident investigation reports, that from 1972 to 1983 “the nation’s railroads experienced at least 21 significant train accidents involving alcohol or drug use as a probable cause or contributing factor,” and that these accidents “resulted in 25 fatalities, 61 non-fatal injuries, and property damage estimated at $19 million (approximately $27 million in 1982 dollars).” 48 Fed. Reg. 30726 (1983). The FRA further identified “an additional 17 fatalities to operating employees working on or around rail rolling stock that involved alcohol or drugs as a contributing factor.” Ibid. In light of these problems, the FRA solicited comments from interested parties on a various regulatory approaches to the problems of alcohol and drug abuse throughout the Nation’s railroad system.

Comments submitted in response to this request indicated that railroads were able to detect a relatively small number of Rule G violations, owing, primarily, to their practice of *608relying on observation by supervisors and co-workers to enforce the rule. 49 Fed. Reg. 24266-24267 (1984). At the same time, “industry participants . . . confirmed that alcohol and drug use [did] occur on the railroads with unacceptable frequency,” and available information from all sources “suggested] that the problem included] ‘pockets’ of drinking and drug use involving multiple crew members (before and during work), sporadic cases of individuals reporting to work impaired, and repeated drinking and drug use by individual employees who are chemically or psychologically dependent on those substances.” Id., at 24253-24254. “Even without the benefit of regular post-accident testing,” the FRA “identified 34 fatalities, 66 injuries and over $28 million in property damage (in 1983 dollars) that resulted from the errors of alcohol and drug-impaired employees in 45 train accidents and train incidents during the period 1975 through 1983.” Id., at 24254. Some of these accidents resulted in the release of hazardous materials and, in one case, the ensuing pollution required the evacuation of an entire Louisiana community. Id., at 24254, 24259. In view of the obvious safety hazards of drug and alcohol use by railroad employees, the FRA announced in June 1984 its intention to promulgate federal regulations on the subject.

B

After reviewing further comments from representatives of the railroad industry, labor groups, and the general public, the FRA, in 1985, promulgated regulations addressing the problem of alcohol and drugs on the railroads. The final regulations apply to employees assigned to perform service subject to the Hours of Service Act, ch. 2939, 34 Stat. 1415, as amended, 45 U. S. C. § 61 et seq. The regulations prohibit covered employees from using or possessing alcohol or any controlled substance. 49 CFR §219.101(a)(1) (1987). The regulations further prohibit those employees from reporting for covered service while under the influence of, or *609impaired by, alcohol, while having a blood alcohol concentration of 0.04 or more, or while under the influence of, or impaired by, any controlled substance. §219.101(a)(2). The regulations do not restrict, however, a railroad’s authority to impose an absolute prohibition on the presence of alcohol or any drug in the body fluids of persons in its employ, §219.101(c), and, accordingly, they do not “replace Rule G or render it unenforceable.” 50 Fed. Reg. 31538 (1985).

To the extent pertinent here, two subparts of the regulations relate to testing. Subpart C, which is entitled “Post-Accident Toxicological Testing,” is mandatory. It provides that railroads “shall take all practicable steps to assure that all covered employees of the railroad directly involved . . . provide blood and urine samples for toxicological testing by FRA,” § 219.203(a), upon the occurrence of certain specified events. Toxicological testing is required following a “major train accident,” which is defined as any train accident that involves (i) a fatality, (ii) the release of hazardous material accompanied by an evacuation or a reportable injury, or (iii) damage to railroad property of $500,000 or more. §219.201 (a)(1). The railroad has the further duty of collecting blood and urine samples for testing after an “impact accident,” which is defined as a collision that results in a reportable injury, or in damage to railroad property of $50,000 or more. § 219.201(a)(2). Finally, the railroad is also obligated to test after “[a]ny train incident that involves a fatality to any on-duty railroad employee.” §219.201(a)(3).

After occurrence of an event which activates its duty to test, the railroad must transport all crew members and other covered employees directly involved in the accident or incident to an independent medical facility, where both blood and urine samples must be obtained from each employee.2 After *610the samples have been collected, the railroad is required to ship them by prepaid air freight to the FRA laboratory for analysis. § 219.205(d). There, the samples are analyzed using “state-of-the-art equipment and techniques” to detect and measure alcohol and drugs.3 The FRA proposes to place primary reliance on analysis of blood samples, as blood is “the only available body fluid . . . that can provide a clear indication not only of the presence of alcohol and drugs but also their current impairment effects.” 49 Fed. Reg. 24291 (1984). Urine samples are also necessary, however, because drug traces remain in the urine longer than in blood, and in some cases it will not be possible to transport employees to a medical facility before the time it takes for certain drugs to be eliminated from the bloodstream. In those instances, a “positive urine test, taken with specific information on the pattern of elimination for the particular drug and other information on the behavior of the employee and the circumstances of the accident, may be crucial to the determination of” the cause of an accident. Ibid.

The regulations require that the FRA notify employees of the results of the tests and afford them an opportunity to respond in writing before preparation of any final investigative report. See § 219.211(a)(2). Employees who refuse to provide required blood or urine samples may not perform cov*611ered service for nine months, but they are entitled to a hearing concerning their refusal to take the test. §219.213.

Subpart D of the regulations, which is entitled “Authorization to Test for Cause,” is permissive. It authorizes railroads to require covered employees to submit to breath or urine tests in certain circumstances not addressed by Sub-part C. Breath or urine tests, or both, may be ordered (1) after a reportable accident or incident, where a supervisor has a “reasonable suspicion” that an employee’s acts or omissions contributed to the occurrence or severity of the accident or incident, § 219.301(b)(2); or (2) in the event of certain specific rule violations, including noncompliance with a signal and excessive speeding, § 219.301(b)(3). A railroad also may require breath tests where a supervisor has a “reasonable suspicion” that an employee is under the influence of alcohol, based upon specific, personal observations concerning the appearance, behavior, speech, or body odors of the employee. § 219.301(b)(1). Where impairment is suspected, a railroad, in addition, may require urine tests, but only if two supervisors make the appropriate determination, §219.301(c)(2)(i), and, where the supervisors suspect impairment due to a substance other than alcohol, at least one of those supervisors must have received specialized training in detecting the signs of drug intoxication, §219.301(c)(2)(ii).

Subpart D further provides that whenever the results of either breath or urine tests are intended for use in a disciplinary proceeding, the employee must be given the opportunity to provide a blood sample for analysis at an independent medical facility. § 219.303(c). If an employee declines to give a blood sample, the railroad may presume impairment, absent persuasive evidence to the contrary, from a positive showing of controlled substance residues in the urine. The railroad must, however, provide detailed notice of this presumption to its employees, and advise them of their right to provide a contemporaneous blood sample. As in the case of samples procured under Subpart C, the regulations set forth *612procedures for the collection of samples, and require that samples “be analyzed by a method that is reliable within known tolerances.” §219.307(b).

C

Respondents, the Railway Labor Executives’ Association and various of its member labor organizations, brought the instant suit in the United States District Court for the Northern District of California, seeking to enjoin the FRA’s regulations on various statutory and constitutional grounds. In a ruling from the bench, the District Court granted summary judgment in petitioners’ favor. The court concluded that railroad employees “have a valid interest in the integrity of their own bodies” that deserved protection under the Fourth Amendment. App. to Pet. for Cert. 53a. The court held, however, that this interest was outweighed by the competing “public and governmental interest in the . . . promotion of . . . railway safety, safety for employees, and safety for the general public that is involved with the transportation. ” Id., at 52a. The District Court found respondents’ other constitutional and statutory arguments meritless.

A divided panel of the Court of Appeals for the Ninth Circuit reversed. Railway Labor Executives’ Assn. v. Burnley, 839 F. 2d 575 (1988). The court held, first, that tests mandated by a railroad in reliance on the authority conferred by Subpart D involve sufficient Government action to implicate the Fourth Amendment, and that the breath, blood, and urine tests contemplated by the FRA regulations are Fourth Amendment searches. The court also “agre[ed] that the exigencies of testing for the presence of alcohol and drugs in blood, urine or breath require prompt action which precludes obtaining a warrant.” Id., at 583. The court further held that “accommodation of railroad employees’ privacy interest with the significant safety concerns of the government does not require adherence to a probable cause requirement,” and, accordingly, that the legality of the searches contemplated by *613the FRA regulations depends on their reasonableness under all the circumstances. Id., at 587.

The court concluded, however, that particularized suspicion is essential to a finding that toxicological testing of railroad employees is reasonable. Ibid. A requirement of individualized suspicion, the court stated, would impose “no insuperable burden on the government,” id., at 588, and would ensure that the tests are confined to the detection of current impairment, rather than to the discovery of “the metabolites of various drugs, which are not evidence of current intoxication and may remain in the body for days or weeks after the ingestion of the drug.” Id., at 588-589. Except for the provisions authorizing breath and urine tests on a “reasonable suspicion” of drug or alcohol impairment, 49 CFR §§219.301(b)(1) and (c)(2) (1987), the FRA regulations did not require a showing of individualized suspicion, and, accordingly, the court invalidated them.

Judge Alarcon dissented. He criticized the majority for “failing] to engage in [a] balancing of interests” and for focusing instead “solely on the degree of impairment of the workers’ privacy interests.” 839 F. 2d, at 597. The dissent would have held that “the government’s compelling need to assure railroad safety by controlling drug use among railway personnel outweighs the need to protect privacy interests.” Id., at 596.

We granted the federal parties’ petition for a writ of certio-rari, 486 U. S. 1042 (1988), to consider whether the regulations invalidated by the Court of Appeals violate the Fourth Amendment. We now reverse.

II

The Fourth Amendment provides that “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated . . . The Amendment guarantees the privacy, dignity, and security of persons against certain ar*614bitrary and invasive acts by officers of the Government or those acting at their direction. Camara v. Municipal Court of San Francisco, 387 U. S. 523, 528 (1967). See also Delaware v. Prouse, 440 U. S. 648, 653-654 (1979); United States v. Martinez-Fuerte, 428 U. S. 543, 554 (1976). Before we consider whether the tests in question are reasonable under the Fourth Amendment, we must inquire whether the tests are attributable to the Government or its agents, and whether they amount to searches or seizures. We turn to those matters.

A

Although the Fourth Amendment does not apply to a search or seizure, even an arbitrary one, effected by a private party on his own initiative, the Amendment protects against such intrusions if the private party acted as an instrument or agent of the Government. See United States v. Jacobsen, 466 U. S. 109, 113-114 (1984); Coolidge v. New Hampshire, 403 U. S. 443, 487 (1971). See also Burdeau v. McDowell, 256 U. S. 465, 475 (1921). A railroad that complies with the provisions of Subpart C of the regulations does so by compulsion of sovereign authority, and the lawfulness of its acts is controlled by the Fourth Amendment. Petitioners contend, however, that the Fourth Amendment is not implicated by Subpart D of the regulations, as nothing in Sub-part D compels any testing by private railroads.

We are unwilling to conclude, in the context of this facial challenge, that breath and urine tests required by private railroads in reliance on Subpart D will not implicate the Fourth Amendment. Whether a private party should be deemed an agent or instrument of the Government for Fourth Amendment purposes necessarily turns on the degree of the Government’s participation in the private party’s activities, cf. Lustig v. United States, 338 U. S. 74, 78-79 (1949) (plurality opinion); Byars v. United States, 273 U. S. 28, 32-33 (1927), a question that can only be resolved “in light of all the circumstances,” Coolidge v. New Hampshire, supra, *615at 487. The fact that the Government has not compelled a private party to perform a search does not, by itself, establish that the search is a private one. Here, specific features of the regulations combine to convince us that the Government did more than adopt a passive position toward the underlying private conduct.

The regulations, including those in Subpart D, pre-empt state laws, rules, or regulations covering the same subject matter, 49 CFR §219.13(a) (1987), and are intended to supersede “any provision of a collective bargaining agreement, or arbitration award construing such an agreement,” 50 Fed. Reg. 31552 (1985). They also confer upon the FRA the right to receive certain biological samples and test results procured by railroads pursuant to Subpart D. §219.11(c). In addition, a railroad may not divest itself of, or otherwise compromise by contract, the authority conferred by Subpart D. As the FRA explained, such “authority ... is conferred for the purpose of promoting the public safety, and a railroad may not shackle itself in a way inconsistent with its duty to promote the public safety.” 50 Fed. Reg. 31552 (1985). Nor is a covered employee free to decline his employer’s request to submit to breath or urine tests under the conditions set forth in Subpart D. See § 219.11(b). An employee who refuses to submit to the tests must be withdrawn from covered service. See 4 App. to Field Manual 18.

In light of these provisions, we are unwilling to accept petitioners’ submission that tests conducted by private railroads in reliance on Subpart D will be primarily the result of private initiative. The Government has removed all legal barriers to the testing authorized by Subpart D, and indeed has made plain not only its strong preference for testing, but also its desire to share the fruits of such intrusions. In addition, it has mandated that the railroads not bargain away the authority to perform tests granted by Subpart D. These are clear indices of the Government’s encouragement, endorse*616ment, and participation, and suffice to implicate the Fourth Amendment.

B

Our precedents teach that where, as here, the Government seeks to obtain physical evidence from a person, the Fourth Amendment may be relevant at several levels. See, e. g., United States v. Dionisio, 410 U. S. 1, 8 (1973). The initial detention necessary to procure the evidence may be a seizure of the person, Cupp v. Murphy, 412 U. S. 291, 294-295 (1973); Davis v. Mississippi, 394 U. S. 721, 726-727 (1969), if the detention amounts to a meaningful interference with his freedom of movement. INS v. Delgado, 466 U. S. 210, 215 (1984); United States v. Jacobsen, supra, at 113, n. 5. Obtaining and examining the evidence may also be a search, see Cupp v. Murphy, supra, at 295; United States v. Dionisio, supra, at 8, 13-14, if doing so infringes an expectation of privacy that society is prepared to recognize as reasonable, see, e. g., California v. Greenwood, 486 U. S. 35, 43 (1988); United States v. Jacobsen, supra, at 113.

We have long recognized that a “compelled intrusio[n] into the body for blood to be analyzed for alcohol content” must be deemed a Fourth Amendment search. See Schmerber v. California, 384 U. S. 757, 767-768 (1966). See also Winston v. Lee, 470 U. S. 753, 760 (1985). In light of our society’s concern for the security of one’s person, see, e. g., Terry v. Ohio, 392 U. S. 1, 9 (1968), it is obvious that this physical intrusion, penetrating beneath the skin, infringes an expectation of privacy that society is prepared to recognize as reasonable. The ensuing chemical analysis of the sample to obtain physiological data is a further invasion of the tested employee’s privacy interests. Cf. Arizona v. Hicks, 480 U. S. 321, 324-325 (1987). Much the same is true of the breath-testing procedures required under Subpart D of the regulations. Subjecting a person to a breathalyzer test, which generally requires the production of alveolar or “deep lung” breath for chemical analysis, see, e. g., California v. *617 Trombetta, 467 U. S. 479, 481 (1984), implicates similar concerns about bodily integrity and, like the blood-alcohol test we considered in Schmerber, should also be deemed a search, see 1 W. LaFave, Search and Seizure § 2.6(a), p. 463 (1987). See also Burnett v. Anchorage, 806 F. 2d 1447, 1449 (CA9 1986); Shoemaker v. Handel, 795 F. 2d 1136, 1141 (CA3), cert. denied, 479 U. S. 986 (1986).

Unlike the blood-testing procedure at issue in Schmerber, the procedures prescribed by the FRA regulations for collecting and testing urine samples do not entail a surgical intrusion into the body. It is not disputed, however, that chemical analysis of urine, like that of blood, can reveal a host of private medical facts about an employee, including whether he or she is epileptic, pregnant, or diabetic. Nor can it be disputed that the process of collecting the sample to be tested, which may in some cases involve visual or aural monitoring of the act of urination, itself implicates privacy interests. As the Court of Appeals for the Fifth Circuit has stated:

“There are few activities in our society more personal or private than the passing of urine. Most people describe it by euphemisms if they talk about it at all. It is a function traditionally performed without public observation; indeed, its performance in public is generally prohibited by law as well as social custom.” National Treasury Employees Union v. Von Raab, 816 F. 2d 170, 175 (1987).

Because it is clear that the collection and testing of urine intrudes upon expectations of privacy that society has long recognized as reasonable, the Federal Courts of Appeals have concluded unanimously, and we agree, that these intrusions must be deemed searches under the Fourth Amendment.4

*618In view of our conclusion that the collection and subsequent analysis of the requisite biological samples must be deemed Fourth Amendment searches, we need not characterize the employer’s antecedent interference with the employee’s freedom of movement as an independent Fourth Amendment seizure. As our precedents indicate, not every governmental interference with an individuál’s freedom of movement raises such constitutional concerns that there is a seizure of the person. See United States v. Dionisio, supra, at 9-11 (grand jury subpoena, though enforceable by contempt, does not effect a seizure of the person); United States v. Mara, 410 U. S. 19, 21 (1973) (same). For present purposes, it suffices to note that any limitation on an employee’s freedom of movement that is necessary to obtain the blood, urine, or breath samples contemplated by the regulations must be considered in assessing the intrusiveness of the searches effected by the Government’s testing program. Cf. United States v. Place, 462 U. S. 696, 707-709 (1983).

I — f t — I I — !

A

To hold that the Fourth Amendment is applicable to the drug and alcohol testing prescribed by the FRA regulations *619is only to begin the inquiry into the standards governing such intrusions. O’Connor v. Ortega, 480 U. S. 709, 719 (1987) (plurality opinion); New Jersey v. T. L. O., 469 U. S. 325, 337 (1985). For the Fourth Amendment does not proscribe all searches and seizures, but only those that are unreasonable. United States v. Sharpe, 470 U. S. 675, 682 (1985); Schmerber v. California, 384 U. S., at 768. What is reasonable, of course, “depends on all of the circumstances surrounding the search or seizure and the nature of the search or seizure itself.” United States v. Montoya de Hernandez, 473 U. S. 531, 537 (1985). Thus, the permissibility of a particular practice “is judged by balancing its intrusion on the individual’s Fourth Amendment interests against its promotion of legitimate governmental interests.” Delaware v. Prouse, 440 U. S., at 654; United States v. Martinez-Fuerte, 428 U. S. 543 (1976).

In most criminal cases, we strike this balance in favor of the procedures described by the Warrant Clause of the Fourth Amendment. See United States v. Place, supra, at 701, and n. 2; United States v. United States District Court, 407 U. S. 297, 315 (1972). Except in certain well-defined circumstances, a search or seizure in such a case is not reasonable unless it is accomplished pursuant to a judicial warrant issued upon probable cause. See, e. g., Payton v. New York, 445 U. S. 573, 586 (1980); Mincey v. Arizona, 437 U. S. 385, 390 (1978). We have recognized exceptions to this rule, however, “when ‘special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable.’” Griffin v. Wisconsin, 483 U. S. 868, 873 (1987), quoting New Jersey v. T. L. O., supra, at 351 (Blackmun, J., concurring in judgment). When faced with such special needs, we have not hesitated to balance the governmental and privacy interests to assess the practicality of the warrant and probable-cause requirements in the particular context. See, e. g., Griffin v. Wisconsin, supra, at 873 (search of probationer’s home); New York v. *620 Burger, 482 U. S. 691, 699-703 (1987) (search of premises of certain highly regulated businesses); O’Connor v. Ortega, supra, at 721-725 (work-related searches of employees’ desks and offices); New Jersey v. T. L. O., supra, at 337-342 (search of student’s property by school officials); Bell v. Wolfish, 441 U. S. 520, 558-560 (1979) (body cavity searches of prison inmates).

The Government’s interest in regulating the conduct of railroad employees to ensure safety, like its supervision of probationers or regulated industries, or its operation of a government office, school, or prison, “likewise presents ‘special needs’ beyond normal law enforcement that may justify departures from the usual warrant and probable-cause requirements.” Griffin v. Wisconsin, supra, at 873-874. The hours of service employees covered by the FRA regulations include persons engaged in handling orders concerning train movements, operating crews, and those engaged in the maintenance and repair of signal systems. 50 Fed. Reg. 31511 (1985). It is undisputed that these and other covered employees are engaged in safety-sensitive tasks. The FRA so found, and respondents conceded the point at oral argument. Tr. of Oral Arg. 46-47. As we have recognized, the whole premise of the Hours of Service Act is that “[t]he length of hours of service has direct relation to the efficiency of the human agencies upon which protection [of] life and property necessarily depends.” Baltimore & Ohio R. Co. v. ICC, 221 U. S. 612, 619 (1911). See also Atchison, T. & S. F. R. Co. v. United States, 244 U. S. 336, 342 (1917) (“[I]t must be remembered that the purpose of the act was to prevent the dangers which must necessarily arise to the employee and to the public from continuing men in a dangerous and hazardous business for periods so long as to render them unfit to give that service which is essential to the protection of themselves and those entrusted to their care”).

The FRA has prescribed toxicological tests, not to assist in the prosecution of employees, but rather “to prevent acci*621dents and casualties in railroad operations that result from impairment of employees by alcohol or drugs.” 49 CFR §219.1(a) (1987).5 This governmental interest in ensuring the safety of the traveling public and of the employees themselves plainly justifies prohibiting covered employees from using alcohol or drugs on duty, or while subject to being called for duty. This interest also “require[s] and justifies] the exercise of supervision to assure that the restrictions are in fact observed.” Griffin v. Wisconsin, supra, at 875. The question that remains, then, is whether the Government’s need to monitor compliance with these restrictions justifies the privacy intrusions at issue absent a warrant or individualized suspicion.

B

An essential purpose of a warrant requirement is to protect privacy interests by assuring citizens subject to a search *622or seizure that such intrusions are not the random or arbitrary acts of government agents. A warrant assures the citizen that the intrusion is authorized by law, and that it is narrowly limited in its objectives and scope. See, e. g., New York v. Burger, supra, at 703; United States v. Chadwick, 433 U. S. 1, 9 (1977); Camara v. Municipal Court of San Francisco, 387 U. S., at 532. A warrant also provides the detached scrutiny of a neutral magistrate, and thus ensures an objective determination whether an intrusion is justified in any given case. See United States v. Chadwick, supra, at 9. In the present context, however, a warrant would do little to further these aims. Both the circumstances justifying toxicological testing and the permissible limits of such intrusions are defined narrowly and specifically in the regulations that authorize them, and doubtless are well known to covered employees. Cf. United States v. Biswell, 406 U. S. 311, 316 (1972). Indeed, in light of the standardized nature of the tests and the minimal discretion vested in those charged with administering the program, there are virtually no facts for a neutral magistrate to evaluate. Cf. Colorado v. Bertine, 479 U. S. 367, 376 (1987) (Blackmun, J., concurring).6

*623We have recognized, moreover, that the government’s interest in dispensing with the warrant requirement is at its strongest when, as here, “the burden of obtaining a warrant is likely to frustrate the governmental purpose behind the search.” Camara v. Municipal Court of San Francisco, supra, at 533. See also New Jersey v. T. L. O., 469 U. S., at 340; Donovan v. Dewey, 452 U. S. 594, 603 (1981). As the FRA recognized, alcohol and other drugs are eliminated from the bloodstream at a constant rate, see 49 Fed. Reg. 24291 (1984), and blood and breath samples taken to measure whether these substances were in the bloodstream when a triggering event occurred must be obtained as soon as possible. See Schmerber v. California, 384 U. S., at 770-771. Although the metabolites of some drugs remain in the urine for longer periods of time and may enable the FRA to estimate whether the employee was impaired by those drugs at the time of a covered accident, incident, or rule violation, 49 Fed. Reg. 24291 (1984), the delay necessary to procure a warrant nevertheless may result in the destruction of valuable evidence.

The Government’s need to rely on private railroads to set the testing process in motion also indicates that insistence on a warrant requirement would impede the achievement of the Government’s objective. Railroad supervisors, like school officials, see New Jersey v. T. L. O., supra, at 339-340, and hospital administrators, see O’Connor v. Ortega, 480 U. S., at 722, are not in the business of investigating violations of the criminal laws or enforcing administrative codes, and otherwise have little occasion to become familiar with the intricacies of this Court’s Fourth Amendment jurisprudence. “Imposing unwieldy warrant procedures . . . upon supervi*624sors, who would otherwise have no reason to be familiar with such procedures, is simply unreasonable.” Ibid.

In sum, imposing a warrant requirement in the present context would add little to the assurances of certainty and regularity already afforded by the regulations, while significantly hindering, and in many cases frustrating, the objectives of the Government’s testing program. We do not believe that a warrant is essential to render the intrusions here at issue reasonable under the Fourth Amendment.

C

Our cases indicate that even a search that may be performed without a warrant must be based, as a general matter, on probable cause to believe that the person to be searched has violated the law. See New Jersey v. T. L. O., supra, at 340. When the balance of interests precludes insistence on a showing of probable cause, we have usually required “some quantum of individualized suspicion” before concluding that a search is reasonable. See, e. g., United States v. Martinez-Fuerte, 428 U. S., at 560. We made it clear, however, that a showing of individualized suspicion is not a constitutional floor, below which a search must be presumed unreasonable. Id., at 561. In limited circumstances, where the privacy interests implicated by the search are minimal, and where an important governmental interest furthered by the intrusion would be placed in jeopardy by a requirement of individualized suspicion, a search may be reasonable despite the absence of such suspicion. We believe this is true of the intrusions in question here.

By and large, intrusions on privacy under the FRA regulations are limited. To the extent transportation and like restrictions are necessary to procure the requisite blood, breath, and urine samples for testing, this interference alone is minimal given the employment context in which it takes place. Ordinarily, an employee consents to significant restrictions in his freedom of movement where necessary for *625his employment, and few are free to come and go as they please during working hours. See, e. g., INS v. Delgado, 466 U. S., at 218. Any additional interference with a railroad employee’s freedom of movement that occurs in the time it takes to procure a blood, breath, or urine sample for testing cannot, by itself, be said to infringe significant privacy interests.

Our decision in Schmerber v. California, supra, indicates that the same is true of the blood tests required by the FRA regulations. In that case, we held that a State could direct that a blood sample be withdrawn from a motorist suspected of driving while intoxicated, despite his refusal to consent to the intrusion. We noted that the test was performed in a reasonable manner, as the motorist’s “blood was taken by a physician in a hospital environment according to accepted medical practices.” Id., at 771. We said also that the intrusion occasioned by a blood test is not significant, since such “tests are a commonplace in these days of periodic physical examinations and experience with them teaches that the quantity of blood extracted is minimal, and that for most people the procedure involves virtually no risk, trauma, or pain.” Ibid. Schmerber thus confirmed “society’s judgment that blood tests do not constitute an unduly extensive imposition on an individual’s privacy and bodily integrity.” Winston v. Lee, 470 U. S., at 762. See also South Dakota v. Neville, 459 U. S. 553, 563 (1983) (“The simple blood-alcohol test is . . . safe, painless, and commonplace”); Breithaupt v. Abram, 352 U. S. 432, 436 (1957) (“The blood test procedure has become routine in our everyday life”).

The breath tests authorized by Subpart D of the regulations are even less intrusive than the blood tests prescribed by Subpart C. Unlike blood tests, breath tests do not require piercing the skin and may be conducted safely outside a hospital environment and with a minimum of inconvenience or embarrassment. Further, breath tests reveal the level of alcohol in the employee’s bloodstream and nothing more. *626Like the blood-testing procedures mandated by Subpart C, which can be used only to ascertain the presence of alcohol or controlled substances in the bloodstream, breath tests reveal no other facts in which the employee has a substantial privacy interest. Cf. United States v. Jacobsen, 466 U. S., at 123; United States v. Place, 462 U. S., at 707. In all the circumstances, we cannot conclude that the administration of a breath test implicates significant privacy concerns.

A more difficult question is presented by urine tests. Like breath tests, urine tests are not invasive of the body and, under the regulations, may not be used as an occasion for inquiring into private facts unrelated to alcohol or drug use.7 We recognize, however, that the procedures for collecting the necessary samples, which require employees to perform an excretory function traditionally shielded by great privacy, raise concerns not implicated by blood or breath tests. While we would not characterize these additional privacy concerns as minimal in most contexts, we note that the regulations endeavor to reduce the intrusiveness of the collection process. The regulations do not require that samples be furnished under the direct observation of a monitor, despite the desirability of such a procedure to ensure the integrity of the sample. See 50 Fed. Reg. 31555 (1985). See also Field Manual B-15, D-l. The sample is also collected in a medical environment, by personnel unrelated to the railroad *627employer, and is thus not unlike similar procedures encountered often in the context of a regular physical examination.

More importantly, the expectations of privacy of covered employees are diminished by reason of their participation in an industry that is regulated pervasively to ensure safety, a goal dependent, in substantial part, on the health and fitness of covered employees. This relation between safety and employee fitness was recognized by Congress when it enacted the Hours of Service Act in 1907, Baltimore & Ohio R. Co. v. ICC, 221 U. S., at 619, and also when it authorized the Secretary to “test. . . railroad facilities, equipment, rolling stock, operations, or persons, as he deems necessary to carry out the provisions” of the Federal Railroad Safety Act of 1970. 45 U. S. C. § 437(a) (emphasis added). It has also been recognized by state governments,8 and has long been reflected in industry practice, as evidenced by the industry’s promulgation and enforcement of Rule G. Indeed, the FRA found, and the Court of Appeals acknowledged, see 839 F. 2d, at 585, that “most railroads require periodic physical examinations for train and engine employees and certain other employees.” 49 Fed. Reg. 24278 (1984). See also Railway Labor Executives Assn. v. Norfolk & Western R. Co., 833 F. 2d 700, 705-706 (CA7 1987); Brotherhood of Maintenance of *628 Way Employees, Lodge 16 v. Burlington Northern R. Co., 802 F. 2d 1016, 1024 (CA8 1986).

We do not suggest, of course, that the interest in bodily security enjoyed by those employed in a regulated industry must always be considered minimal. Here, however, the covered employees have long been a principal focus of regulatory concern. As the dissenting judge below noted: “The reason is obvious. An idle locomotive, sitting in the roundhouse, is harmless. It becomes lethal when operated negligently by persons who are under the influence of alcohol or drugs.” 839 F. 2d, at 593. Though some of the privacy interests implicated by the toxicological testing at issue reasonably might be viewed as significant in other contexts, logic and history show that a diminished expectation of privacy attaches to information relating to the physical condition of covered employees and to this reasonable means of procuring such information. We conclude, therefore, that the testing procedures contemplated by Subparts C and D pose only limited threats to the justifiable expectations of privacy of covered employees.

By contrast, the Government interest in testing without a showing of individualized suspicion is compelling. Employees subject to the tests discharge duties fraught with such risks of injury to others that even a momentary lapse of attention can have disastrous consequences. Much like persons who have routine access to dangerous nuclear power facilities, see, e. g., Rushton v. Nebraska Public Power Dist., 844 F. 2d 562, 566 (CA8 1988); Alverado v. Washington Public Power Supply System, 111 Wash. 2d 424, 436, 759 P. 2d 427, 433-434 (1988), cert. pending, No. 88-645, employees who are subject to testing under the FRA regulations can cause great human loss before any signs of impairment become noticeable to supervisors or others. An impaired employee, the FRA found, will seldom display any outward “signs detectable by the lay person or, in many cases, even the physician.” 50 Fed. Reg. 31526 (1985). This view finds *629ample support in the railroad industry’s experience with Rule G, and in the judgment of the courts that have examined analogous testing schemes. See, e. g., Brotherhood of Maintenance Way Employees, Lodge 16 v. Burlington Northern R. Co., supra, at 1020. Indeed, while respondents posit that impaired employees might be detected without alcohol or drug testing,9 the premise of respondents’ lawsuit is that even the occurrence of a major calamity will not give rise to a suspicion of impairment with respect to any particular employee.

While no procedure can identify all impaired employees with ease and perfect accuracy, the FRA regulations supply an effective means of deterring employees engaged in safety-sensitive tasks from using controlled substances or alcohol in the first place. 50 Fed. Reg. 31541 (1985). The railroad industry’s experience with Rule G persuasively shows, and common sense confirms, that the customary dismissal sanc*630tion that threatens employees who use drugs or alcohol while on duty cannot serve as an effective deterrent unless violators know that they are likely to be discovered. By ensuring that employees in safety-sensitive positions know they will be tested upon the occurrence of a triggering event, the timing of which no employee can predict with certainty, the regulations significantly increase the deterrent effect of the administrative penalties associated with the prohibited conduct, cf. Griffin v. Wisconsin, 483 U. S., at 876, concomitantly increasing the likelihood that employees will forgo using drugs or alcohol while subject to being called for duty.

The testing procedures contemplated by Subpart C also help railroads obtain invaluable information about the causes of major accidents, see 50 Fed. Reg. 31541 (1985), and to take appropriate measures to safeguard the general public. Cf. Michigan v. Tyler, 436 U. S. 499, 510 (1978) (noting that prompt investigation of the causes of a fire may uncover continuing dangers and thereby prevent the fire’s recurrence); Michigan v. Clifford, 464 U. S. 287, 308 (1984) (Rehnquist, J., dissenting) (same). Positive test results would point toward drug or alcohol impairment on the part of members of the crew as a possible cause of an accident, and may help to establish whether a particular accident, otherwise not drug related, was made worse by the inability of impaired employees to respond appropriately. Negative test results would likewise furnish invaluable clues, for eliminating drug impairment as a potential cause or contributing factor would help establish the significance of equipment failure, inadequate training, or other potential causes, and suggest a more thorough examination of these alternatives. Tests performed following the rule violations specified in Subpart D likewise can provide valuable information respecting the causes of those transgressions, which the FRA found to involve “the potential for a serious train accident or grave personal injury, or both.” 50 Fed. Reg. 31553 (1985).

*631A requirement of particularized suspicion of drug or alcohol use would seriously impede an employer’s ability to obtain this information, despite its obvious importance. Experience confirms the FRA’s judgment that the scene of a serious rail accident is chaotic. Investigators who arrive at the scene shortly after a major accident has occurred may find it difficult to determine which members of a train crew contributed to its occurrence. Obtaining evidence that might give rise to the suspicion that a particular employee is impaired, a difficult endeavor in the best of circumstances, is most impracticable in the aftermath of a serious accident. While events following the rule violations that activate the testing authority of Subpart D may be less chaotic, objective indicia of impairment are absent in these instances as well. Indeed, any attempt to gather evidence relating to the possible impairment of particular employees likely would result in the loss or deterioration of the evidence furnished by the tests. Cf. Michigan v. Clifford, supra, at 293, n. 4 (plurality opinion); Michigan v. Tyler, supra, at 510. It would be unrealistic, and inimical to the Government’s goal of ensuring safety in rail transportation, to require a showing of individualized suspicion in these circumstances.

Without quarreling with the importance of these governmental interests, the Court of Appeals concluded that the postaccident testing regulations were unreasonable because “[b]lood and urine tests intended to establish drug use other than alcohol. . . cannot measure current drug intoxication or degree of impairment.” 839 F. 2d, at 588. The court based its conclusion on its reading of certain academic journals that indicate that the testing of urine can disclose only drug metabolites, which “may remain in the body for days or weeks after the ingestion of the drug.” Id., at 589. We find this analysis flawed for several reasons.

As we emphasized in New Jersey v. T. L. O., “it is universally recognized that evidence, to be relevant to an inquiry, need not conclusively prove the ultimate fact in issue, but *632only have ‘any tendency to make the existence of any fact that is of consequence to the determination [of the point in issue] more probable or less probable than it would be without the evidence.’” 469 U. S., at 345, quoting Fed. Rule Evid. 401. Even if urine test results disclosed nothing more specific than the recent use of controlled substances by a covered employee, this information would provide the basis for further investigative work designed to determine whether the employee used drugs at the relevant times. See Field Manual B-4. The record makes clear, for example, that a positive test result, coupled with known information concerning the pattern of elimination for the particular drug and information that may be gathered from other sources about the employee’s activities, may allow the FRA to reach an informed judgment as to how a particular accident occurred. See supra, at 609-610.

More importantly, the Court of Appeals overlooked the FRA’s policy of placing principal reliance on the results of blood tests, which unquestionably can identify very recent drug use, see, e. g., 49 Fed. Reg. 24291 (1984), while relying on urine tests as a secondary source of information designed to guard against the possibility that certain drugs will be eliminated from the bloodstream before a blood sample can be obtained. The court also failed to recognize that the FRA regulations are designed not only to discern impairment but also to deter it. Because the record indicates that blood and urine tests, taken together, are highly effective means of ascertaining on-the-job impairment and of deterring the use of drugs by railroad employees, we believe the Court of Appeals erred in concluding that the postaccident testing regulations are not reasonably related to the Government objectives that support them.10

*633We conclude that the compelling Government interests served by the FRA’s regulations would be significantly hindered if railroads were required to point to specific facts giving rise to a reasonable suspicion of impairment before testing a given employee. In view of our conclusion that, on the present record, the toxicological testing contemplated by the regulations is not an undue infringement on the justifiable expectations of privacy of covered employees, the Government’s compelling interests outweigh privacy concerns.

IV

The possession of unlawful drugs is a criminal offense that the Government may punish, but it is a separate and far more dangerous wrong to perform certain sensitive tasks while under the influence of those substances. Performing those tasks while impaired by alcohol is, of course, equally dangerous, though consumption of alcohol is legal in most other contexts. The Government may take all necessary and reasonable regulatory steps to prevent or deter that hazardous conduct, and since the gravamen of the evil is performing certain functions while concealing the substance in the body, it may be necessary, as in the case before us, to examine the body or its fluids to accomplish the regulatory purpose. The necessity to perform that regulatory function with respect to railroad employees engaged in safety-sensitive tasks, and the reasonableness of the system for doing so, have been established in this case.

Alcohol and drug tests conducted in reliance on the authority of Subpart D cannot be viewed as private action outside the reach of the Fourth Amendment. Because the testing procedures mandated or authorized by Subparts C and D ef-*634feet searches of the person, they must meet the Fourth Amendment’s reasonableness requirement. In light of the limited discretion exercised by the railroad employers under the regulations, the surpassing safety interests served by toxicological tests in this context, and the diminished expectation of privacy that attaches to information pertaining to the fitness of covered employees, we believe that it is reasonable to conduct such tests in the absence of a warrant or reasonable suspicion that any particular employee may be impaired. We hold that the alcohol and drug tests contemplated by Subparts C and D of the FRA’s regulations are reasonable within the meaning of the Fourth Amendment. The judgment of the Court of Appeals is accordingly reversed.

It is so ordered.

Justice Stevens,

concurring in part and concurring in the judgment.

In my opinion the public interest in determining the causes of serious railroad accidents adequately supports the validity of the challenged regulations. I am not persuaded, however, that the interest in deterring the use of alcohol or drugs is either necessary or sufficient to justify the searches authorized by these regulations.

I think it a dubious proposition that the regulations significantly deter the use of alcohol and drugs by hours of service employees. Most people — and I would think most railroad employees as well — do not go to work with the expectation that they may be involved in a major accident, particularly one causing such catastrophic results as loss of life or the release of hazardous material requiring an evacuation. Moreover, even if they are conscious of the possibilities that such an accident might occur and that alcohol or drug use might be a contributing factor, if the risk of serious personal injury does not deter their use of these substances, it seems highly unlikely that the additional threat of loss of employment would have any effect on their behavior.

*635For this reason, I do not join the portions of Part III of the Court’s opinion that rely on a deterrence rationale; I do, however, join the balance of the opinion and the Court’s judgment.

Justice Marshall,

with whom Justice Brennan joins, dissenting.

The issue in this case is not whether declaring a war on illegal drugs is good public policy. The importance of ridding our society of such drugs is, by now, apparent to all. Rather, the issue here is whether the Government’s deployment in that war of a particularly Draconian weapon — the compulsory collection and chemical testing of railroad workers’ blood and urine — comports with the Fourth Amendment. Precisely because the need for action against the drug scourge is manifest, the need for vigilance against unconstitutional excess is great. History teaches that grave threats to liberty often come in times of urgency, when constitutional rights seem too extravagant to endure. The World War II relocation-camp cases, Hirabayashi v. United States, 320 U. S. 81 (1943); Korematsu v. United States, 323 U. S. 214 (1944), and the Red scare and McCarthy-era internal subversion cases, Schenck v. United States, 249 U. S. 47 (1919); Dennis v. United States, 341 U. S. 494 (1951), are only the most extreme reminders that when we allow fundamental freedoms to be sacrificed in the name of real or perceived exigency, we invariably come to regret it.

In permitting the Government to force entire railroad crews to submit to invasive blood and urine tests, even when it lacks any evidence of drug or alcohol use or other wrongdoing, the majority today joins those shortsighted courts which have allowed basic constitutional rights to fall prey to momentary emergencies. The majority holds that the need of the Federal Railroad Administration (FRA) to deter and diagnose train accidents outweighs any “minimal” intrusions on personal dignity and privacy posed by mass toxicological testing of persons who have given no indication whatsoever of *636impairment. Ante, at 624. In reaching this result, the majority ignores the text and doctrinal history of the Fourth Amendment, which require that highly intrusive searches of this type be based on probable cause, not on the evanescent cost-benefit calculations of agencies or judges. But the majority errs even under its own utilitarian standards, trivializing the raw intrusiveness of, and overlooking serious conceptual and operational flaws in, the FRA’s testing program. These flaws cast grave doubts on whether that program, though born of good intentions, will do more than ineffectually symbolize the Government’s opposition to drug use.

The majority purports to limit its decision to postaccident testing of workers in “safety-sensitive” jobs, ante, at 620, much as it limits its holding in the companion case to the testing of transferees to jobs involving drug interdiction or the use of firearms. Treasury Employees v. Von Raab, post, at 664. But the damage done to the Fourth Amendment is not so easily cabined. The majority’s acceptance of dragnet blood and urine testing ensures that the first, and worst, casualty of the war on drugs will be the precious liberties of our citizens. I therefore dissent.

I

The Court today takes its longest step yet toward reading the probable-cause requirement out of the Fourth Amendment. For the fourth time in as many years, a majority holds that a “‘special nee[d], beyond the normal need for law enforcement,’” makes the “‘requirement’” of probable cause “‘impracticable.’” Ante, at 619 (citations omitted). With the recognition of “[t]he Government’s interest in regulating the conduct of railroad employees to ensure safety” as such a need, ante, at 620, the Court has now permitted “special needs” to displace constitutional text in each of the four categories of searches enumerated in the Fourth Amendment: searches of “persons,” ante, at 613-614; “houses,” Griffin v. Wisconsin, 483 U. S. 868 (1987); “papers,” O’Connor v. Or *637 tega, 480 U. S. 709 (1987); and “effects,” New Jersey v. T. L. O., 469 U. S. 325 (1985).

The process by which a constitutional “requirement” can be dispensed with as “impracticable” is an elusive one to me. The Fourth Amendment provides that “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated; and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.” The majority’s recitation of the Amendment, remarkably, leaves off after the word “violated,” ante, at 613, but the remainder of the Amendment — the Warrant Clause — is not so easily excised. As this Court has long recognized, the Framers intended the provisions of that Clause — a warrant and probable cause — to “provide the yardstick against which official searches and seizures are to be measured.” T. L. O., supra, at 359-360 (opinion of Brennan, J.). Without the content which those provisions give to the Fourth Amendment’s overarching command that searches and seizures be “reasonable,” the Amendment lies virtually devoid of meaning, subject to whatever content shifting judicial majorities, concerned about the problems of the day, choose to give to that supple term. See Dunaway v. New York, 442 U. S. 200, 213 (1979) (“[T]he protections intended by the Framers could all too easily disappear in the consideration and balancing of the multifarious circumstances presented by different cases”). Constitutional requirements like probable cause are not fair-weather friends, present when advantageous, conveniently absent when “special needs” make them seem not.

Until recently, an unbroken line of cases had recognized probable cause as an indispensable prerequisite for a full-scale search, regardless of whether such a search was conducted pursuant to a warrant or under one of the recognized exceptions to the warrant requirement. T. L. O., supra, at 358 *638and 359, n. 3 (opinion of Brennan, J.); see also Chambers v. Maroney, 399 U. S. 42, 51 (1970). Only where the government action in question had a “substantially less intrusive” impact on privacy, Dunaway, 442 U. S., at 210, and thus clearly fell short of a full-scale search, did we relax the probable-cause standard. Id., at 214 (“For all but those narrowly defined intrusions, the requisite ‘balancing’ ... is embodied in the principle that seizures are ‘reasonable’ only if supported by probable cause”); see also T. L. O., supra, at 360 (opinion of Brennan, J.). Even in this class of cases, we almost always required the government to show some individualized suspicion to justify the search.1 The few searches which we upheld in the absence of individualized justification were routinized, fleeting, and nonintrusive encounters conducted pursuant to regulatory programs which entailed no contact with the person.2

*639In the four years since this Court, in T. L. O., first began recognizing “special needs” exceptions to the Fourth Amendment, the clarity of Fourth Amendment doctrine has been badly distorted, as the Court has eclipsed the probable-cause requirement in a patchwork quilt of settings: public school principals’ searches of students’ belongings, T. L. O.; public employers’ searches of employees’ desks, O’Connor; and probation officers’ searches of probationers’ homes, Griffin, 3 Tellingly, each time the Court has found that “special needs” counseled ignoring the literal requirements of the Fourth Amendment for such full-scale searches in favor of a formless and unguided “reasonableness” balancing inquiry, it has concluded that the search in question satisfied that test. I have joined dissenting opinions in each of these cases, protesting the “jettison[ing of] . . . the only standard that finds support in the text of the Fourth Amendment” and predicting that the majority’s “Rohrsehach-like ‘balancing test’” portended “a dangerous weakening of the purpose of the Fourth Amendment to protect the privacy and security of our citizens.” T. L. O., supra, at 357-358 (opinion of Brennan, J.).

The majority’s decision today bears out that prophecy. After determining that the Fourth Amendment applies to the FRA’s testing regime, the majority embarks on an extended inquiry into whether that regime is “reasonable,” an inquiry in which it balances “‘all of the circumstances surrounding the search or seizure and the nature of the search or seizure itself.’” Ante, at 619, quoting United States v. Montoya de *640 Hernandez, 473 U. S. 531, 537 (1985). The result is “special needs” balancing analysis’ deepest incursion yet into the core protections of the Fourth Amendment. Until today, it was conceivable that, when a government search was aimed at a person and not simply the person’s possessions, balancing analysis had no place. No longer: with nary a word of explanation or acknowledgment of the novelty of its approach, the majority extends the “special needs” framework to a regulation involving compulsory blood withdrawal and urinary excretion, and chemical testing of the bodily fluids collected through these procedures. And until today, it was conceivable that a prerequisite for surviving “special needs” analysis was the existence of individualized suspicion. No longer: in contrast to the searches in T. L. O., O’Connor, and Griffin, which were supported by individualized evidence suggesting the culpability of the persons whose property was searched,4 the regulatory regime upheld today requires the postaccident collection and testing of the blood and urine of all covered employees — even if every member of this group gives every indication of sobriety and attentiveness.

In widening the “special needs” exception to probable cause to authorize searches of the human body unsupported by any evidence of wrongdoing, the majority today completes the process begun in T. L. O. of eliminating altogether the probable-cause requirement for civil searches — those undertaken for reasons “beyond the normal need for law enforcement.” Ante, at 619 (citations omitted). In its place, the majority substitutes a manipulable balancing inquiry under which, upon the mere assertion of a “special need,” even the deepest dignitary and privacy interests become vul*641nerable to governmental incursion. See ibid, (distinguishing criminal from civil searches). By its terms, however, the Fourth Amendment — unlike the Fifth and Sixth — does not confine its protections to either criminal or civil actions. Instead, it protects generally “[t]he right of the people to be secure.”5

The fact is that the malleable “special needs” balancing approach can be justified only on the basis of the policy results it allows the majority to reach. The majority’s concern with the railroad safety problems caused by drug and alcohol abuse is laudable; its cavalier disregard for the text of the Constitution is not. There is no drug exception to the Constitution, any more than there is a communism exception or an exception for other real or imagined sources of domestic unrest. Coolidge v. New Hampshire, 403 U. S. 443, 455 (1971). Because abandoning the explicit protections of the Fourth Amendment seriously imperils “the right to be let alone — the most comprehensive of rights and the right most valued by civilized men,” Olmstead v. United States, 277 U. S. 438, 478 (1928) (Brandeis, J., dissenting), I reject the majority’s “special needs” rationale as unprincipled and dangerous.

II

The proper way to evaluate the FRA’s testing regime is to use the same analytic framework which we have traditionally used to appraise Fourth Amendment claims involving full-scale searches, at least until the recent “special needs” cases. Under that framework, we inquire, serially, whether a *642search has taken place, see, e. g., Katz v. United States, 389 U. S. 347, 350-353 (1967); whether the search was based on a valid warrant or undertaken pursuant to a recognized exception to the warrant requirement, see, e. g., Welsh v. Wisconsin, 466 U. S. 740, 748-750 (1984); whether the search was based on probable cause or validly based on lesser suspicion because it was minimally intrusive, see, e. g., Dunaway, 442 U. S., at 208-210; and, finally, whether the search was conducted in a reasonable manner, see, e. g., Winston v. Lee, 470 U. S. 753, 763-766 (1985). See also T. L. O., 469 U. S., at 354-355 (opinion of Brennan, J.) (summarizing analytic framework).

The majority’s threshold determination that “covered” railroad employees have been searched under the FRA’s testing program is certainly correct. Ante, at 616-618. Who among us is not prepared to consider reasonable a person’s expectation of privacy with respect to the extraction of his blood, the collection of his urine, or the chemical testing of these fluids? United States v. Jacobsen, 466 U. S. 109, 113 (1984).6 The majority’s ensuing conclusion that the warrant requirement may be dispensed with, however, conveniently overlooks the fact that there are three distinct searches at issue. Although the importance of collecting blood and urine samples before drug or alcohol metabolites disappear justifies waiving the warrant requirement for those two searches under the narrow “exigent circumstances” exception, see Schmerber v. California, 384 U. S. 757, 770 (1966) (“[T]he delay necessary to obtain a warrant. . . threatens] ‘the destruction of evidence’ ”), no such exigency prevents railroad officials from securing a warrant before chemically testing the samples they obtain. Blood and urine do not spoil if *643properly collected and preserved, and there is no reason to doubt the ability of railroad officials to grasp the relatively simple procedure of obtaining a warrant authorizing, where appropriate, chemical analysis of the extracted fluids. It is therefore wholly unjustified to dispense with the warrant requirement for this final search. See Chimel v. California, 395 U. S. 752, 761-764 (1969) (exigency exception permits warrantless searches only to the extent that exigency exists).

It is the probable-cause requirement, however, that the FRA’s testing regime most egregiously violates, a fact which explains the majority’s ready acceptance and expansion of the countertextual “special needs” exception. By any measure, the FRA’s highly intrusive collection and testing procedures qualify as full-scale personal searches. Under our precedents, a showing of probable cause is therefore clearly required. But even if these searches were viewed as entailing only minimal intrusions on the order, say, of a police stop- and-frisk, the FRA’s program would still fail to pass constitutional muster, for we have, without exception, demanded that even minimally intrusive searches of the person be founded on individualized suspicion. See supra, at 638, and n. 1. The federal parties concede it does not satisfy this standard. Brief for Federal Parties 18. Only if one construes the FRA’s collection and testing procedures as akin to the routinized and fleeting regulatory interactions which we have permitted in the absence of individualized suspicion, see n. 2, supra, might these procedures survive constitutional scrutiny. Presumably for this reason, the majority likens this case to United States v. Martinez-Fuerte, 428 U. S. 543 (1976), which upheld brief automobile stops, at the border to ascertain the validity of motorists’ residence in the United States. Ante, at 624. CaseTaw and common sense reveal both the bankruptcy of this absurd analogy and the constitutional imperative of adhering to the textual standard of probable cause to evaluate the FRA’s multifarious full-scale searches.

*644Compelling a person to submit to the piercing of his skin by a hypodermic needle so that his blood may be extracted significantly intrudes on the “personal privacy and dignity against unwarranted intrusion by the State” against which the Fourth Amendment protects. Schmerber, supra, at 767. As we emphasized in Terry v. Ohio, 392 U. S. 1, 24-25 (1968), “Even a limited search of the outer clothing . . . constitutes a severe, though brief, intrusion upon cherished personal security, and it must surely be an annoying, frightening, and perhaps humiliating experience.” We have similarly described the taking of a suspect’s fingernail scrapings as a “ ‘severe, though brief, intrusion upon cherished personal security.’” Cupp v. Murphy, 412 U. S. 291, 295 (1973) (quoting Terry, supra, at 24-25, and upholding this procedure upon a showing of probable cause). The government-compelled withdrawal of blood, involving as it does the added aspect of physical invasion, is surely no less an intrusion. The surrender of blood on demand is, furthermore, hardly a quotidian occurrence. Cf. Martinez-Fuerte, supra, at 557 (routine stops involve “quite limited” intrusion).

In recognition of the intrusiveness of this procedure, we specifically required in Schmerber that police have evidence of a drunken-driving suspect’s impairment before forcing him to endure a blood test:

“The interests in human dignity and privacy which the Fourth Amendment protects forbid any such intrusions on the mere chance that desired evidence might be obtained. In the absence of a clear indication that in fact such evidence will be found, these fundamental human interests require law officers to suffer the risk that such evidence may disappear . . . .” 384 U. S., at 769-770.

Schmerber strongly suggested that the “clear indication” needed to justify a compulsory blood test amounted to a showing of probable cause, which “plainly” existed in that case. Id., at 768. Although subsequent cases interpreting Schmerber have differed over whether a showing of individ*645ualized suspicion would have sufficed, compare Winston, 470 U. S., at 760 (Schmerber “noted the importance of probable cause”), with Montoya de Hernandez, 473 U. S., at 540 (Schmerber “indicate[d] the necessity for particularized suspicion”), by any reading, Schmerber clearly forbade compulsory blood tests on any lesser showing than individualized suspicion. Exactly why a blood test which, if conducted on one person, requires a showing of at least individualized suspicion may, if conducted on many persons, be based on no showing whatsoever, the majority does not — and cannot — explain.7

Compelling a person to produce a urine sample on demand also intrudes deeply on privacy and bodily integrity. Urination is among the most private of activities. It is generally forbidden in public, eschewed as a matter of conversation, and performed in places designed to preserve this tradition of *646personal seclusion. Cf. Martinez-Fuerte, 428 U. S., at 560 (border-stop questioning involves no more than “some annoyance” and is neither “frightening” nor “offensive”). The FRA, however, gives scant regard to personal privacy, for its Field Manual instructs supervisors monitoring urination that railroad workers must provide urine samples “under direct observation by the physician/technician.” Federal Railroad Administration, United States Dept, of Transportation, Field Manual: Control of Alcohol and Drug Use in Railroad Operations D-5 (1986) (emphasis added).8 That the privacy interests offended by compulsory and supervised urine collection are profound is the overwhelming judgment of the lower courts and commentators. As Professor — later Solicitor General — Charles Fried has written:

“[I]n our culture the excretory functions are shielded by more or less absolute privacy, so much so that situations in which this privacy is violated are experienced as extremely distressing, as detracting from one’s dignity and self esteem.” Privacy, 77 Yale L. J. 475, 487 (1968).9

The majority’s characterization of the privacy interests implicated by urine collection as “minimal,” ante, at 624, is noth*647ing short of startling. This characterization is, furthermore, belied by the majority’s own prior explanation of why compulsory urination constitutes a search for the purposes of the Fourth Amendment:

“ ‘There are few activities in our society more personal or private than the passing of urine. Most people describe it by euphemisms if they talk about it at all. It is a function traditionally performed without public observation; indeed, its performance in public is generally prohibited by law as well as social custom.’” Ante, at 617, quoting National Treasury Employees Union v. Von Raab, 816 F. 2d 170, 175 (CA5 1987).

The fact that the majority can invoke this powerful passage in the context of deciding that a search has occurred, and then ignore it in deciding that the privacy interests this search implicates are “minimal,” underscores the shameless manipulability of its balancing approach.

Finally, the chemical analysis the FRA performs upon the blood and urine samples implicates strong privacy interests apart from those intruded upon by the collection of bodily fluids. Technological advances have made it possible to uncover, through analysis of chemical compounds in these fluids, not only drug or alcohol use, but also medical disorders such as epilepsy, diabetes, and clinical depression. Cf. Martinez-Fuerte, supra, at 558, quoting United States v. Brignoni-Ponce, 422 U. S. 873, 880 (1975) (checkpoint inquiry involves only “ ‘a brief question or two’ ” about motorist’s residence). As the Court of Appeals for the District of Columbia Circuit has observed: “[S]uch tests may provide Government officials with a periscope through which they can peer into an individual’s behavior in her private life, even in her own home.” Jones v. McKenzie, 266 U. S. App. D. C. 85, 89, 833 F. 2d 335, 339 (1987); see also Capua v. Plainfield, 643 F. Supp. 1507, 1511 (NJ 1986) (urine testing is “form of surveillance” which “reports on a person’s off-duty activities just as surely as someone had been present and *648watching”)- The FRA’s requirement that workers disclose the medications they have taken during the 30 days prior to chemical testing further impinges upon the confidentiality customarily attending personal health secrets.

By any reading of our precedents, the intrusiveness of these three searches demands that they — like other full-scale searches — be justified by probable cause. It is no answer to suggest, as does the majority, that railroad workers have relinquished the protection afforded them by this Fourth Amendment requirement, either by “participating] in an industry that is regulated pervasively to ensure safety” or by undergoing periodic fitness tests pursuant to state law or to collective-bargaining agreements. Ante, at 627.

Our decisions in the regulatory search area refute the suggestion that the heavy regulation of the railroad industry eclipses workers’ rights under the Fourth Amendment to insist upon a showing of probable cause when their bodily fluids are being extracted. This line of cases has exclusively involved searches of employer property, with respect to which “[c]ertain industries have such a history of government oversight that no reasonable expectation of privacy could exist for a proprietor over the stock of such an enterprise.” Marshall v. Barlow’s, Inc., 436 U. S. 307, 313 (1978) (emphasis added; citation omitted), quoted in New York v. Burger, 482 U. S. 691, 700 (1987). Never have we intimated that regulatory searches reduce employees’ rights of privacy in their persons. See Camara v. Municipal Court of San Francisco, 387 U. S. 523, 537 (1967) (“[T]he inspections are [not] personal in nature”); cf. Donovan v. Dewey, 452 U. S. 594, 598-599 (1981); Marshall, supra, at 313. As the Court pointed out in O’Con-nor, individuals do not lose Fourth Amendment rights at the workplace gate, 480 U. S., at 716-718; see also Oliver v. United States, 466 U. S. 170, 178, n. 8 (1984), any more than they relinquish these rights at the schoolhouse door, T. L. O., 469 U. S., at 333, or the hotel room threshold, Hoff a v. United States, 385 U. S. 293, 301 (1966). These rights mean *649little indeed if, having passed through these portals, an individual may remain subject to a suspicionless search of his person justified solely on the grounds that the government already is permitted to conduct a search of the inanimate contents of the surrounding area. In holding that searches of persons may fall within the category of regulatory searches permitted in the absence of probable cause or even individualized suspicion, the majority sets a dangerous and ill-conceived precedent.

The majority’s suggestion that railroad workers’ privacy is only minimally invaded by the collection and testing of their bodily fluids because they undergo periodic fitness tests, ante, at 624-625, is equally baseless. As an initial matter, even if participation in these fitness tests did render “minimal” an employee’s “interest in bodily security,” ante, at 628, such minimally intrusive searches of the person require, under our precedents, a justificatory showing of individualized suspicion. See supra, at 637. More fundamentally, railroad employees are not routinely required to submit to blood or urine tests to gain or to maintain employment, and railroad employers do not ordinarily have access to employees’ blood or urine, and certainly not for the purpose of ascertaining drug or alcohol usage. That railroad employees sometimes undergo tests of eyesight, hearing, skill, intelligence, and agility, ante, at 627, n. 8, hardly prepares them for Government demands to submit to the extraction of blood, to excrete under supervision, or to have these bodily fluids tested for the physiological and psychological secrets they may contain. Surely employees who release basic information about their financial and personal history so that employers may ascertain their “ethical fitness” do not, by so doing, relinquish their expectations of privacy with respect to their personal letters and diaries, revealing though these papers may be of their character.

I recognize that invalidating the full-scale searches involved in the FRA’s testing regime for failure to comport with the Fourth Amendment’s command of probable cause *650may hinder the Government’s attempts to make rail transit as safe as humanly possible. But constitutional rights have their consequences, and one is that efforts to maximize the public welfare, no matter how well intentioned, must always be pursued within constitutional boundaries. Were the police freed from the constraints of the Fourth Amendment for just one day to seek out evidence of criminal wrongdoing, the resulting convictions and incarcerations would probably prevent thousands of fatalities. Our refusal to tolerate this specter reflects our shared belief that even beneficent governmental power — whether exercised to save money, save lives, or make the trains run on time — must always yield to “a resolute loyalty to constitutional safeguards.” Almeida-Sanchez v. United States, 413 U. S. 266, 273 (1973). The Constitution demands no less loyalty here.

I — I K — I hH

Even accepting the majority’s view that the FRA s collection and testing program is appropriately analyzed under a multifactor balancing test, and not under the literal terms of the Fourth Amendment, I would still find the program invalid. The benefits of suspicionless blood and urine testing are far outstripped by the costs imposed on personal liberty by such sweeping searches. Only by erroneously deriding as “minimal” the privacy and dignity interests at stake, and by uncritically inflating the likely efficacy of the FRA’s testing program, does the majority strike a different balance.

For the reasons stated above, I find nothing minimal about the intrusion on individual liberty that occurs whenever the Government forcibly draws and analyzes a person’s blood and urine. Several aspects of the FRA’s testing program exacerbate the intrusiveness of these procedures. Most strikingly, the agency’s regulations not only do not forbid, but, in fact, appear to invite criminal prosecutors to obtain the blood and urine samples drawn by the FRA and use them as the basis of criminal investigations and trials. See 49 CFR *651§ 219.211(d) (1987) (“Each sample . . . may be made available to ... a party in litigation upon service of appropriate compulsory process on the custodian of the sample . . .”). This is an unprecedented invitation, leaving open the possibility of criminal prosecutions based on suspicionless searches of the human body. Cf. Treasury Employees, post, at 666 (Customs Service drug-testing program prohibits use of test results in criminal prosecutions); Camara, 387 U. S., at 537.

Tobe sure, the majority acknowledges, in passing, the possibility of criminal prosecutions, ante, at 621, n. 5-, but it refuses to factor this possibility into its Fourth Amendment balancing process, stating that “the record does not disclose that [49 CFR § 219.211(d) (1987)] was intended to be, or actually has been, so used.” Ibid. This demurrer is highly disingenuous. The federal parties concede that they find “no prohibition on the release of FRA testing results to prosecutors.” Brief for Federal Parties 10, n. 15. The absence of prosecutions to date — which is likely due to the fact that the FRA’s regulations have been held invalid for much of their brief history — hardly proves that prosecutors will not avail themselves of the FRA’s invitation in the future. If the majority really views the impact of FRA testing on privacy interests as minimal even if these tests generate criminal prosecutions, it should say so. If the prospect of prosecutions would lead the majority to reassess the validity of the testing program with prosecutions as part of the balance, it should say so, too, or condition its approval of that program on the nonrelease of test results to prosecutors. In ducking this important issue, the majority gravely disserves both the values served by the Fourth Amendment and the rights of those persons whom the FRA searches. Furthermore, the majority’s refusal to restrict the release of test results casts considerable doubt on the conceptual basis of its decision— that the “special need” of railway safety is one “beyond the *652normal need for law enforcement.” Ante, at 619 (citations omitted).10

The majority also overlooks needlessly intrusive aspects of the testing process itself. Although the FRA requires the collection and testing of both blood and urine, the agency concedes that mandatory urine tests — unlike blood tests — do not measure current impairment and therefore cannot differentiate on-duty impairment from prior drug or alcohol use which has ceased to affect the user’s behavior. See 49 CFR § 219.309(2) (1987) (urine test may reveal use of drugs or alcohol as much as 60 days prior to sampling). Given that the FRA’s stated goal is to ascertain current impairment, and not to identify persons who have used substances in their spare time sufficiently in advance of their railroad duties to pose no risk of on-duty impairment, §219.101(a), mandatory urine testing seems wholly excessive. At the very least, the FRA could limit its use of urinalysis to confirming findings of current impairment suggested by a person’s blood tests. The additional invasion caused by automatically testing urine as well as blood hardly ensures that privacy interests “will be invaded no more than is necessary.” T. L. O., 469 U. S., at 343.

The majority’s trivialization of the intrusions on worker privacy posed by the FRA’s testing program is matched at the other extreme by its blind acceptance of the Government’s assertion that testing will “dete[r] employees engaged in safety-sensitive tasks from using controlled substances or alcohol,” and “help railroads obtain invaluable information *653about the causes of major accidents.” Ante, at 629, 630. With respect, first, to deterrence, it is simply implausible that testing employees after major accidents occur, 49 CFR § 219.201(a)(1) (1987), will appreciably discourage them from using drugs or alcohol. As Justice Stevens observes in his concurring opinion:

“Most people — and I would think most railroad employees as well — do not go to work with the expectation that they may be involved in a major accident, particularly one causing such catastrophic results as loss of life or the release of hazardous material requiring an evacuation. Moreover, even if they are conscious of the possibilities that such an accident might occur and that alcohol or drug use might be a contributing factor, if the risk of serious personal injury does not deter their use of these substances, it seems highly unlikely that the additional threat of loss of employment would have any effect on their behavior.” Ante, at 634.

Under the majority’s deterrence rationale, people who skip school or work to spend a sunny day at the zoo will not taunt the lions because their truancy or absenteeism might be discovered in the event they are mauled. It is, of course, the fear of the accident, not the fear of a postaccident revelation, that deters. The majority’s credulous acceptance of the FRA’s deterrence rationale is made all the more suspect by the agency’s failure to introduce, in an otherwise ample administrative record, any studies explaining or supporting its theory of accident deterrence.

The poverty of the majority’s deterrence rationale leaves the Government’s interest in diagnosing the causes of major accidents as the sole remaining justification for the FRA’s testing program. I do not denigrate this interest, but it seems a slender thread from which to hang such an intrusive program, particularly given that the knowledge that one or more workers were impaired at the time of an accident falls far short of proving that substance abuse caused or exacer*654bated that accident. See 839 F. 2d 575, 587 (CA9 1988). Some corroborative evidence is needed: witness or co-worker accounts of a worker’s misfeasance, or at least indications that the cause of the accident was within a worker’s area of responsibility. Such particularized facts are, of course, the very essence of the individualized suspicion requirement which the respondent railroad workers urge, and which the Court of Appeals found to “pos[e] no insuperable burden on the government.” Id., at 588. Furthermore, reliance on the importance of diagnosing the causes of an accident as a critical basis for upholding the FRA’s testing plan is especially hard to square with our frequent admonition that the interest in ascertaining the causes of a criminal episode does not justify departure from the Fourth Amendment’s requirements. “[T]his Court has never sustained a search upon the sole ground that officers reasonably expected to find evidence of a particular crime . . . .” Katz, 389 U. S., at 356. Nor should it here.

IV

In his first dissenting opinion as a Member of this Court, Oliver Wendell Holmes observed:

“Great cases, like hard cases, make bad law. For great cases are called great, not by reason of their real importance in shaping the law of the future, but because of some accident of immediate overwhelming interest which appeals to the feelings and distorts the judgment. These immediate interests exercise a kind of hydraulic pressure which makes what previously was clear seem doubtful, and before which even well settled principles of law will bend.” Northern Securities Co. v. United States, 193 U. S. 197, 400-401 (1904).

A majority of this Court, swept away by society’s obsession with stopping the scourge of illegal drugs, today succumbs to the popular pressures described by Justice Holmes. In upholding the FRA’s plan for blood and urine testing, the *655majority bends time-honored and textually based principles of the Fourth Amendment — principles the Framers of the Bill of Rights designed to ensure that the Government has a strong and individualized justification when it seeks to invade an individual’s privacy. I believe the Framers would be appalled by the vision of mass governmental intrusions upon the integrity of the human body that the majority allows to become reality. The immediate victims of the majority’s constitutional timorousness will be those railroad workers whose bodily fluids the Government may now forcibly collect and analyze. But ultimately, today's decision will reduce the privacy all citizens may enjoy, for, as Justice Holmes understood, principles of law, once bent, do not snap back easily. I dissent.

Justice Kennedy

delivered the opinion of the Court.

We granted certiorari to decide whether it violates the Fourth Amendment for the United States Customs Service to require a urinalysis test from employees who seek transfer or promotion to certain positions.

I

A

The United States Customs Service, a bureau of the Department of the Treasury, is the federal agency responsible for processing persons, carriers, cargo, and mail into the United States, collecting revenue from imports, and enforcing customs and related laws. See United States Customs Service, Customs U. S. A., Fiscal Year 1985, p. 4. An important responsibility of the Service is the interdiction and *660seizure of contraband, including illegal drugs. Ibid. In 1987 alone, Customs agents seized drugs with a retail value of nearly $9 billion. See United States Customs Service, Customs U. S. A., Fiscal Year 1987, p. 40. In the routine discharge of their duties, many Customs employees have direct contact with those who traffic in drugs for profit. Drug import operations, often directed by sophisticated criminal syndicates, United States v. Mendenhall, 446 U. S. 544, 561-562 (1980) (Powell, J., concurring), may be effected by violence or its threat. As a necessary response, many Customs operatives carry and use firearms in connection with their official duties. App. 109.

In December 1985, respondent, the Commissioner of Customs, established a Drug Screening Task Force to explore the possibility of implementing a drug-screening program within the Service. Id., at 11. After extensive research and consultation with experts in the field, the task force concluded that “drug screening through urinalysis is technologically reliable, valid and accurate.” Ibid. Citing this conclusion, the Commissioner announced his intention to require drug tests of employees who applied for, or occupied, certain positions within the Service. Id., at 10-11. The Commissioner stated his belief that “Customs is largely drug-free,” but noted also that “unfortunately no segment of society is immune from the threat of illegal drug use.” Id., at 10. Drug interdiction has become the agency’s primary enforcement mission, and the Commissioner stressed that “there is no room in the Customs Service for those who break the laws prohibiting the possession and use of illegal drugs.” Ibid.

In May 1986, the Commissioner announced implementation of the drug-testing program. Drug tests were made a condition of placement or employment for positions that meet one or more of three criteria. The first is direct involvement in drug interdiction or enforcement of related laws, an activity the Commissioner deemed fraught with obvious dangers to the mission of the agency and the lives of Customs *661agents. Id., at 17, 113. The second criterion is a requirement that the incumbent carry firearms, as the Commissioner concluded that “[pjublic safety demands that employees who carry deadly arms and are prepared to make instant life or death decisions be drug free.” Id., at 113. The third criterion is a requirement for the incumbent to handle “classified” material, which the Commissioner determined might fall into the hands of smugglers if accessible to employees who, by reason of their own illegal drug use, are susceptible to bribery or blackmail. Id., at 114.

After an employee qualifies for a position covered by the Customs testing program, the Service advises him by letter that his final selection is contingent upon successful completion of drug screening. An independent contractor contacts the employee to fix the time and place for collecting the sample. On reporting for the test, the employee must produce photographic identification and remove any outer garments, such as a coat or a jacket, and personal belongings. The employee may produce the sample behind a partition, or in the privacy of a bathroom stall if he so chooses. To ensure against adulteration of the specimen, or substitution of a sample from another person, a monitor of the same sex as the employee remains close at hand to listen for the normal sounds of urination. Dye is added to the toilet water to prevent the employee from using the water to adulterate the sample.

Upon receiving the specimen, the monitor inspects it to ensure its proper temperature and color, places a tamper-proof custody seal over the container, and affixes an identification label indicating the date and the individual’s specimen number. The employee signs a chain-of-custody form, which is initialed by the monitor, and the urine sample is placed in a plastic bag, sealed, and submitted to a laboratory.1

*662The laboratory tests the sample for the presence of marijuana, cocaine, opiates, amphetamines, and phencyclidine. Two tests are used. An initial screening test uses the enzyme-multiplied-immunoassay technique (EMIT). Any specimen that is identified as positive on this initial test must then be confirmed using gas chromatography/mass spectrometry (GC/MS). Confirmed positive results are reported to a “Medical Review Officer,” “[a] licensed physician. . . who has knowledge of substance abuse disorders and has appropriate medical training to interpret and evaluate an individual’s positive test result together with his or her medical history and any other relevant biomedical information.” HHS Reg. § 1.2, *66353 Fed. Reg. 11980 (1988); HHS Reg. §2.4(g), 53 Fed. Reg., at 11983. 'After verifying the positive result, the Medical Review Officer transmits it to the agency.

Customs employees.who test positive for drugs and who can offer no satisfactory explanation are subject to dismissal from the Service. Test results may not, however, be turned over to any other agency, including criminal prosecutors, without the employee’s written consent.

B

Petitioners, a union of federal employees and a union official, commenced this suit in the United States District Court for the Eastern District of Louisiana on behalf of current Customs Service employees who seek covered positions. Petitioners alleged that the Custom Service drug-testing program violated, inter alia, the Fourth Amendment. The District Court agreed. 649 F. Supp. 380 (1986). The court acknowledged “the legitimate governmental interest in a drug-free work place and work force,” but concluded that “the drug testing plan constitutes an overly intrusive policy of searches and seizures without probable cause or reasonable suspicion, in violation of legitimate expectations of privacy.” Id., at 387. The court enjoined the drug-testing program, and ordered the Customs Service not to require drug tests of any applicants for covered positions.

A divided panel of the United States Court of Appeals for the Fifth Circuit vacated the injunction. 816 F. 2d 170 (1987). The court agreed with petitioners that the drug-screening program, by requiring an employee to produce a urine sample for chemical testing, effects a search within the meaning of the Fourth Amendment. The court held further that the searches required by the Commissioner’s directive are reasonable under the Fourth Amendment. It first noted that “[t]he Service has attempted to minimize the intrusiveness of the search” by not requiring visual observation of the act of urination and by affording notice to the employee that *664he will be tested. Id., at 177. The court also considered it significant that the program limits discretion in determining which employees are to be tested, ibid., and noted that the tests are an aspect of the employment relationship, id., at 178.

The court further found that the Government has a strong interest in detecting drug use among employees who meet the criteria of the Customs program. It reasoned that drug use by covered employees casts substantial doubt on their ability to discharge their duties honestly and vigorously, undermining public confidence in the integrity of the Service and concomitantly impairing the Service’s efforts to enforce the drug laws. Ibid. Illicit drug users, the court found, are susceptible to bribery and blackmail, may be tempted to divert for their own use portions of any drug shipments they interdict, and may, if required to carry firearms, “endanger the safety of their fellow agents, as well as their own, when their performance is impaired by drug use.” Ibid. “Considering the nature and responsibilities of the jobs for which applicants are being considered at Customs and the limited scope of the search,” the court stated, “the exaction of consent as a condition of assignment to the new job is not unreasonable.” Id., at 179.

The dissenting judge concluded that the Customs program is not an effective method for achieving the Service’s goals. He argued principally that an employee “given a five day notification of a test date need only abstain from drug use to prevent being identified as a user.” Id., at 184. He noted also that persons already employed in sensitive positions are not subject to the test. Ibid. Because he did not believe the Customs program can achieve its purposes, the dissenting judge found it unreasonable under the Fourth Amendment.

We granted certiorari. 485 U. S. 903 (1988). We now affirm so much of the judgment of the Court of Appeals as upheld the testing of employees directly involved in drug interdiction or required to carry firearms. We vacate the *665judgment to the extent it upheld the testing of applicants for positions requiring the incumbent to handle classified materials, and remand for further proceedings. II

hH

In Skinner v. Railway Labor Executives’ Assn., ante, at 616-618, decided today, we held that federal regulations requiring employees of private railroads to produce urine samples for chemical testing implicate the Fourth Amendment, as those tests invade reasonable expectations of privacy. Our earlier cases have settled that the Fourth Amendment protects individuals from unreasonable searches conducted by the Government, even when the Government acts as an employer, O’Connor v. Ortega, 480 U. S. 709, 717 (1987) (plurality opinion); see id., at 731 (Scalia, J., concurring in judgment), and, in view of our holding in Railway Labor Executives that urine tests are searches, it follows that the Customs Service’s drug-testing program must meet the reasonableness requirement of the Fourth Amendment.

While we have often emphasized, and reiterate today, that a search must be supported, as a general matter, by a warrant issued upon probable cause, see, e. g., Griffin v. Wisconsin, 483 U. S. 868, 873 (1987); United States v. Karo, 468 U. S. 705, 717 (1984), our decision in Railway Labor Executives reaffirms the longstanding principle that neither a warrant nor probable cause, nor, indeed, any measure of individualized suspicion, is an indispensable component of reasonableness in every circumstance. Ante, at 618-624. See also New Jersey v. T. L. O., 469 U. S. 325, 342, n. 8 (1985); United States v. Martinez-Fuerte, 428 U. S. 543, 556-661 (1976). As we note in Railway Labor Executives, our cases establish that where a Fourth Amendment intrusion serves special governmental needs, beyond the normal need for law enforcement, it is necessary to balance the individual’s privacy expectations against the Government’s interests to determine whether it is impractical to require a warrant or *666some level of individualized suspicion in the particular context. Ante, at 619-620.

It is clear that the Customs Service’s drug-testing program is not designed to serve the ordinary needs of law enforcement. Test results may not be used in a criminal prosecution of the employee without the employee’s consent. The purposes of the program are to deter drug use among those eligible for promotion to sensitive positions within the Service and to prevent the promotion of drug users to those positions. These substantial interests, no less than the Government’s concern for safe rail transportation at issue in Railway Labor Executives, present a special need that may justify departure from the ordinary warrant and probable-cause requirements.

A

Petitioners do not contend that a warrant is required by the balance of privacy and governmental interests in this context, nor could any such contention withstand scrutiny. We have recognized before that requiring the Government to procure a warrant for every work-related intrusion “would conflict with ‘the common-sense realization that government offices could not function if every employment decision became a constitutional matter.’” O’Connor v. Ortega, supra, at 722, quoting Connick v. Myers, 461 U. S. 138, 143 (1983). See also 480 U. S., at 732 (Scalia, J., concurring in judgment); New Jersey v. T. L. O., supra, at 340 (noting that “[t]he warrant requirement ... is unsuited to the school environment: requiring a teacher to obtain a warrant before searching a child suspected of an infraction of school rules (or of the criminal law) would unduly interfere with the maintenance of the swift and informal disciplinary procedures needed in the schools”). Even if Customs Service employees are more likely to be familiar with the procedures required to obtain a warrant than most other Government workers, requiring a warrant in this context would serve only to divert valuable agency resources from the Service’s primary mis*667sion. The Customs Service has been entrusted with pressing responsibilities, and its mission would be compromised if it were required to seek search warrants in connection with routine, yet sensitive, employment decisions.

Furthermore, a warrant would provide little or nothing in the way of additional protection of personal privacy. A warrant serves primarily to advise the citizen that an intrusion is authorized by law and limited in its permissible scope and to interpose a neutral magistrate between the citizen and the law enforcement officer “engaged in the often competitive enterprise of ferreting out crime.” Johnson v. United States, 333 U. S. 10, 14 (1948). But in the present context, “the circumstances justifying toxicological testing and the permissible limits of such intrusions are defined narrowly and specifically . . . , and doubtless are well known to covered employees.” Ante, at 622. Under the Customs program, every employee who seeks a transfer to a covered position knows that he must take a drug test, and is likewise aware of the procedures the Service must follow in administering the test. A covered employee is simply not subject “to the discretion of the official in the field.” Camara v. Municipal Court of San Francisco, 387 U. S. 523, 532 (1967). The process becomes automatic when the employee elects to apply for, and thereafter pursue, a covered position. Because the Service does not make a discretionary determination to search based on a judgment that certain conditions are present, there are simply “no special facts for a neutral magistrate to evaluate.” South Dakota v. Opperman, 428 U. S. 364, 383 (1976) (Powell, J., concurring).

B

Even where it is reasonable to dispense with the warrant requirement in the particular circumstances, a search ordinarily must be based on probable cause. Ante, at 624. Our cases teach, however, that the probable-cause standard “ ‘is peculiarly related to criminal investigations.’” Colorado v. Bertine, 479 U. S. 367, 371 (1987), quoting South Dakota v. *668 Opperman, supra, at 370, n. 5. In particular, the traditional probable-cause standard may be unhelpful in analyzing the reasonableness of routine administrative functions, Colorado v. Bertine, supra, at 371; see also O’Connor v. Ortega, 480 U. S., at 723, especially where the Government seeks to prevent the development of hazardous conditions or to detect violations that rarely generate articulable grounds for searching any particular place or person. Cf. Camara v. Municipal Court of San Francisco, supra, at 535-536 (noting that building code inspections, unlike searches conducted pursuant to a criminal investigation, are designed “to prevent even the unintentional development of conditions which are hazardous to public health and safety”); United States v. Martinez-Fuerte, 428 U. S., at 557 (noting that requiring particularized suspicion before routine stops on major highways near the Mexican border “would be impractical because the flow of traffic tends to be too heavy to allow the particularized study of a given car that would enable it to be identified as a possible carrier of illegal aliens”). Our precedents have settled that, in certain limited circumstances, the Government’s need to discover such latent or hidden conditions, or to prevent their development, is sufficiently compelling to justify the intrusion on privacy entailed by conducting such searches without any measure of individualized suspicion. E. g., ante, at 624. We think the Government’s need to conduct the suspicionless searches required by the Customs program outweighs the privacy interests of employees engaged directly in drug interdiction, and of those who otherwise are required to carry firearms.

The Customs Service is our Nation’s first line of defense against one of the greatest problems affecting the health and welfare of our population. We have adverted before to “the veritable national crisis in law enforcement caused by smuggling of illicit narcotics.” United States v. Montoya de Hernandez, 473 U. S. 531, 538 (1985). See also Florida v. Royer, 460 U. S. 491, 513 (Blackmun, J., dissenting). Our *669cases also reflect the traffickers’ seemingly inexhaustible repertoire of deceptive practices and elaborate schemes for importing narcotics, e. g., United States v. Montoya de Hernandez, supra, at 538-539; United States v. Ramsey, 431 U. S. 606, 608-609 (1977). The record in this case confirms that, through the adroit selection of source locations, smuggling routes, and increasingly elaborate methods of concealment, drug traffickers have managed to bring into this country increasingly large quantities of illegal drugs. App. 111. The record also indicates, and it is well known, that drug smugglers do not hesitate to use violence to protect their lucrative trade and avoid apprehension. Id., at 109.

Many of the Service’s employees are often exposed to this criminal element and to the controlled substances it seeks to smuggle into the country. Ibid. Cf. United States v. Montoya de Hernandez, supra, at 543. The physical safety of these employees may be threatened, and many may be tempted not only by bribes from the traffickers with whom they deal, but also by their own access to vast sources of valuable contraband seized and controlled by the Service. The Commissioner indicated below that “Customs [officers have been shot, stabbed, run over, dragged by automobiles, and assaulted with blunt objects while performing their duties.” App. at 109-110. At least nine officers have died in the line of duty since 1974. He also noted that Customs officers have been the targets of bribery by drug smugglers on numerous occasions, and several have been removed from the Service for accepting bribes and for other integrity violations. Id., at 114. See also United States Customs Service, Customs U. S. A., Fiscal Year 1987, p. 31 (reporting internal investigations that resulted in the arrest of 24 employees and 54 civilians); United States Customs Service, Customs U. S. A., Fiscal Year 1986, p. 32 (reporting that 334 criminal and serious integrity investigations were conducted during the fiscal year, resulting in the arrest of 37 employees and 17 civilians); United States Customs Service, Customs *670U. S. A., Fiscal Year 1985, p. 32 (reporting that 284 criminal and serious integrity investigations were conducted during the 1985 fiscal year, resulting in the arrest of 15 employees and 51 civilians).

It is readily apparent that the Government has a compelling interest in ensuring that front-line interdiction personnel are physically fit, and have unimpeachable integrity and judgment. Indeed, the Government’s interest here is at least as important as its interest in searching travelers entering the country. We have long held that travelers seeking to enter the country may be stopped and required to submit to a routine search without probable cause, or even founded suspicion, “because of national self protection reasonably requiring one entering the country to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in.” Carroll v. United States, 267 U. S. 132, 154 (1925). See also United States v. Montoya de Hernandez, supra, at 538; United States v. Ramsey, supra, at 617-619. This national interest in self-protection could be irreparably damaged if those charged with safeguarding it were, because of their own drug use, unsympathetic to their mission of interdicting narcotics. A drug user’s indifference to the Service’s basic mission or, even worse, his active complicity with the malefactors, can facilitate importation of sizable drug shipments or block apprehension of dangerous criminals. The public interest demands effective measures to bar drug users from positions directly involving the interdiction of illegal drugs.

The public interest likewise demands effective measures to prevent the promotion of drug users to positions that require the incumbent to carry a firearm, even if the incumbent is not engaged directly in the interdiction of drugs. Customs employees who may use deadly force plainly “discharge duties fraught with such risks of injury to others that even a momentary lapse of attention can have disastrous consequences.” Ante, at 628. We agree with the Government *671that the public should not bear the risk that employees who may suffer from impaired perception and judgment will be promoted to positions where they may need to employ deadly force. Indeed, ensuring against the creation of this dangerous risk will itself further Fourth Amendment values, as the use of deadly force may violate the Fourth Amendment in certain circumstances. See Tennessee v. Garner, 471 U. S. 1, 7-12 (1985).

Against these valid public interests we must weigh the interference with individual liberty that results from requiring these classes of employees to undergo a urine test. The interference with individual privacy that results from the collection of a urine sample for subsequent chemical analysis could be substantial in some circumstances. Ante, at 626. We have recognized, however, that the “operational realities of the workplace” may render entirely reasonable certain work-related intrusions by supervisors and co-workers that might be viewed as unreasonable in other contexts. See O’Connor v. Ortega, 480 U. S., at 717; id., at 732 (Scalia, J., concurring in judgment). While these operational realities will rarely affect an employee’s expectations of privacy with respect to searches of his person, or of personal effects that the employee may bring to the workplace, id., at 716, 725, it is plain that certain forms of public employment may diminish privacy expectations even with respect to such personal searches. Employees of the United States Mint, for example, should expect to be subject to certain routine personal searches when they leave the workplace every day. Similarly, those who join our military or intelligence services may not only be required to give what in other contexts might be viewed as extraordinary assurances of trustworthiness and probity, but also may expect intrusive inquiries into their physical fitness for those special positions. Cf. Snepp v. United States, 444 U. S. 507, 509, n. 3 (1980); Parker v. Levy, 417 U. S. 733, 758 (1974); Committee for GI Rights v. *672 Callaway, 171 U. S. App. D. C. 73, 84, 518 F. 2d 466, 477 (1975).

We think Customs employees who are directly involved in the interdiction of illegal drugs or who are required to carry firearms in the line of duty likewise have a diminished expectation of privacy in respect to the intrusions occasioned by a urine test. Unlike most private citizens or government employees in general, employees involved in drug interdiction reasonably should expect effective inquiry into their fitness and probity. Much the same is true of employees who are required to carry firearms. Because successful performance of their duties depends uniquely on their judgment and dexterity, these employees cannot reasonably expect to keep from the Service personal information that bears directly on their fitness. Cf. In re Caruso v. Ward, 72 N. Y. 2d 433, 441, 530 N. E. 2d 850, 854-855 (1988). While reasonable tests designed to elicit this information doubtless infringe some privacy expectations, we do not believe these expectations outweigh the Government’s compelling interests in safety and in the integrity of our borders.2

*673Without disparaging the importance of the governmental interests that support the suspicionless searches of these employees, petitioners nevertheless contend that the Service’s drug-testing program is unreasonable in two particulars. First, petitioners argue that the program is unjustified because it is not based on a belief that testing will reveal any drug use by covered employees. In pressing this argument, petitioners point out that the Service’s testing scheme was not implemented in response to any perceived drug problem among Customs employees, and that the program actually has not led to the discovery of a significant number of drug users. Brief for Petitioners 37, 44; Tr. of Oral Arg. 11-12, 20-21. Counsel for petitioners informed us at oral argument that no more than 5 employees out of 3,600 have tested positive for drugs. Id., at 11. Second, petitioners contend that the Service’s scheme is not a “sufficiently productive mechanism to justify [its] intrusion upon Fourth Amendment interests,” Delaware v. Prouse, 440 U. S. 648, 658-659 (1979), because illegal drug users can avoid detection with ease by temporary abstinence or by surreptitious adulteration of their urine specimens. Brief for Petitioners 46-47. These contentions are unpersuasive.

*674Petitioners’ first contention evinces an unduly narrow view of the context in which the Service’s testing program was implemented. Petitioners do not dispute, nor can there be doubt, that drug abuse is one of the most serious problems confronting our society today. There is little reason to believe that American workplaces are immune from this pervasive social problem, as is amply illustrated by our decision in Railway Labor Executives. See also Masino v. United States, 589 P. 2d 1048, 1050 (Ct. Cl. 1978) (describing marijuana use by two Customs inspectors). Detecting drug impairment on the part of employees can be a difficult task, especially where, as here, it is not feasible to subject employees and their work product to the kind of day-to-day scrutiny that is the norm in more traditional office environments. Indeed, the almost unique mission of the Service gives the Government a compelling interest in ensuring that many of these covered employees do not use drugs even off duty, for such use creates risks of bribery and blackmail against which the Government is entitled to guard. In light of the extraordinary safety and national security hazards that would attend the promotion of drug users to positions that require the carrying of firearms or the interdiction of controlled substances, the Service’s policy of deterring drug users from seeking such promotions cannot be deemed unreasonable.

The mere circumstance that all but a few of the employees tested are entirely innocent of wrongdoing does not impugn the program’s validity. The same is likely to be true of householders who are required to submit to suspicionless housing code inspections, see Camara v. Municipal Court of San Francisco, 387 U. S. 523 (1967), and of motorists who are stopped at the checkpoints we approved in United States v. Martinez-Fuerte, 428 U. S. 543 (1976). The Service’s program is designed to prevent the promotion of drug users to sensitive positions as much as it is designed to detect those employees who use drugs. Where, as here, the possible harm against which the Government seeks to guard is *675substantial, the need to prevent its occurrence furnishes an ample justification for reasonable searches calculated to advance the Government’s goal.3

*676We think petitioners’ second argument — that the Service’s testing program is ineffective because employees may attempt to deceive the test by a brief abstention before the test date, or by adulterating their urine specimens — overstates the case. As the Court of Appeals noted, addicts may be unable to abstain even for a limited period of time, or may be unaware of the “fade-away effect” of certain drugs. 816 F. 2d, at 180. More importantly, the avoidance techniques suggested by petitioners are fraught with uncertainty and risks for those employees who venture to attempt them. A particular employee’s pattern of elimination for a given drug cannot be predicted with perfect accuracy, and, in any event, this information is not likely to be known or available to the employee. Petitioners’ own expert indicated below that the time it takes for particular drugs to become undetectable in urine can vary widely depending on the individual, and may extend for as long as 22 days. App. 66. See also ante, at 631 (noting Court of Appeals’ reliance on certain academic literature that indicates that the testing of urine can discover drug use “ ‘for. . . weeks after the ingestion of the drug’ ”). Thus, contrary to petitioners’ suggestion, no employee reasonably can expect to deceive the test by the simple expedient of abstaining after the test date is assigned. Nor can he expect attempts at adulteration to succeed, in view of the precautions taken by the sample collector to ensure the integrity of the sample. In all the circumstances, we are persuaded that the program bears a close and substantial relation to the Service’s goal of deterring drug users from seeking promotion to sensitive positions.4

*677In sum, we believe the Government has demonstrated that its compelling interests in safeguarding our borders and the public safety outweigh the privacy expectations of employees who seek to be promoted to positions that directly involve the interdiction of illegal drugs or that require the incumbent to carry a firearm. We hold that the testing of these employees is reasonable under the Fourth Amendment.

C

We are unable, on the present record, to assess the reasonableness of the Government’s testing program insofar as it covers employees who are required “to handle classified material.” App. 17. We readily agree that the Government has a compelling interest in protecting truly sensitive information from those who, “under compulsion of circumstances or for other reasons, . . . might compromise [such] information.” Department of Navy v. Egan, 484 U. S. 518, 528 (1988). See also United States v. Robel, 389 U. S. 258, 267 (1967) (“We have recognized that, while the Constitution protects against invasions of individual rights, it does not withdraw from the Government the power to safeguard its vital interests. . . . The Government can deny access to its secrets to those who would use such information to harm the Nation”). We also agree that employees who seek promotions to positions where they would handle sensitive information can be required to submit to a urine test under the Service’s screening program, especially if the positions covered under this category require background investigations, medical examinations, or other intrusions that may be expected to diminish their expectations of privacy in respect of a urinalysis test. Cf. Department of Navy v. Egan, supra, at 528 (noting that the Executive Branch generally subjects those desir*678ing a security clearance to “a background investigation that varies according to the degree of adverse effect the applicant could have on the national security”).

It is not clear, however, whether the category defined by the Service’s testing directive encompasses only those Customs employees likely to gain access to sensitive information. Employees who are tested under the Service’s scheme include those holding such diverse positions as “Accountant,” “Accounting Technician,” “Animal Caretaker,” “Attorney (All),” “Baggage Clerk,” “Co-op Student (All),” “Electric Equipment Repairer,” “Mail Clerk/Assistant,” and “Messenger.” App. 42-43. We assume these positions were selected for coverage under the Service’s testing program by reason of the incumbent’s access to “classified” information, as it is not clear that they would fall under either of the two categories we have already considered. Yet it is not evident that those occupying these positions are likely to gain access to sensitive information, and this apparent discrepancy raises in our minds the question whether the Service has defined this category of employees more broadly than is necessary to meet the purposes of the Commissioner’s directive.

We cannot resolve this ambiguity on the basis of the record before us, and we think it is appropriate to remand the case to the Court of Appeals for such proceedings as may be necessary to clarify the scope of this category of employees subject to testing. Upon remand the Court of Appeals should examine the criteria used by the Service in determining what materials are classified and in deciding whom to test under this rubric. In assessing the reasonableness of requiring tests of these employees, the court should also consider pertinent information bearing upon the employees’ privacy expectations, as well as the supervision to which these employees are already subject.

Ill

Where the Government requires its employees to produce urine samples to be analyzed for evidence of illegal drug *679use, the collection and subsequent chemical analysis of such samples are searches that must meet the reasonableness requirement of the Fourth Amendment. Because the testing program adopted by the Customs Service is not designed to serve the ordinary' needs of law enforcement, we have balanced the public interest in the Service’s testing program against the privacy concerns implicated by the tests, without reference to our usual presumption in favor of the procedures specified in the Warrant Clause, to assess whether the tests required by Customs are reasonable.

We hold that the suspicionless testing of employees who apply for promotion to positions directly involving the interdiction of illegal drugs, or to positions that require the incumbent to carry a firearm, is reasonable. The Government’s compelling interests in preventing the promotion of drug users to positions where they might endanger the integrity of our Nation’s borders or the life of the citizenry outweigh the privacy interests of those who seek promotion to these positions, who enjoy a diminished expectation of privacy by virtue of the special, and obvious, physical and ethical demands of those positions. We do not decide whether testing those who apply for promotion to positions where they would handle “classified” information is reasonable because we find the record inadequate for this purpose.

The judgment of the Court of Appeals for the Fifth Circuit is affirmed in part and vacated in part, and the case is remanded for further proceedings consistent with this opinion.

It is so ordered.

Justice Marshall,

with whom Justice Brennan joins, dissenting.

For the reasons stated in my dissenting opinion in Skinner v. Railway Labor Executives’ Assn., ante, p. 635, I also dissent from the Court’s decision in this case. Here, as in Skinner, the Court’s abandonment of the Fourth Amendment’s express requirement that searches of the person rest on *680probable cause is unprincipled and unjustifiable. But even if I believed that balancing analysis was appropriate under the Fourth Amendment, I would still dissent from today’s judgment for the reasons stated by Justice Scalia in his dissenting opinion, post this page, and for the reasons noted by the dissenting judge below relating to the inadequate tailoring of the Customs Service’s drug-testing plan. See 816 F. 2d 170, 182-184 (CA5 1987) (Hill, J.).

Justice Scalia,

with whom Justice Stevens joins, dissenting.

The issue in this case is not whether Customs Service employees can constitutionally be denied promotion, or even dismissed, for a single instance of unlawful drug use, at home or at work. They assuredly can. The issue here is what steps can constitutionally be taken to detect such drug use. The Government asserts it can demand that employees perform “an excretory function traditionally shielded by great privacy,” Skinner v. Railway Labor Executives’ Assn., ante, at 626, while “a monitor of the same sex . . . remains close at hand to listen for the normal sounds,” ante, at 661, and that the excretion thus produced be turned over to the Government for chemical analysis. The Court agrees that this constitutes a search for purposes of the Fourth Amendment— and I think it obvious that it is a type of search particularly destructive of privacy and offensive to personal dignity.

Until today this Court had upheld a bodily search separate from arrest and without individualized suspicion of wrongdoing only with respect to prison inmates, relying upon the uniquely dangerous nature of that environment. See Bell v. Wolfish, 441 U. S. 520, 558-560 (1979). Today, in Skinner, we allow a less intrusive bodily search of railroad employees involved in train accidents. I joined the Court’s opinion there because the demonstrated frequency of drug and alcohol use by the targeted class of employees, and the demonstrated connection between such use and grave harm, rendered the search a reasonable means of protecting society. *681I decline to join the Court’s opinion in the present case because neither frequency of use nor connection to harm is demonstrated or even likely. In my view the Customs Service rules are a kind of immolation of privacy and human dignity in symbolic opposition to drug use.

The Fourth Amendment protects the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” While there are some absolutes in Fourth Amendment law, as soon as those have been left behind and the question comes down to whether a particular search has been “reasonable,” the answer depends largely upon the social necessity that prompts the search. Thus, in upholding the administrative search of a student’s purse in a school, we began with the observation (documented by an agency report to Congress) that “[m]ain-taining order in the classroom has never been easy, but in recent years, school disorder has often taken particularly ugly forms: drug use and violent crime in the schools have become major social problems.” New Jersey v. T. L. O., 469 U. S. 325, 339 (1985). When we approved fixed checkpoints near the Mexican border to stop and search cars for illegal aliens, we observed at the outset that “the Immigration and Naturalization Service now suggests there may be as many as 10 or 12 million aliens illegally in the country,” and that “[interdicting the flow of illegal entrants from Mexico poses formidable law enforcement problems.” United States v. Martinez-Fuerte, 428 U. S. 543, 551-552 (1976). And the substantive analysis of our opinion today in Skinner begins, “[t]he problem of alcohol use on American railroads is as old as the industry itself,” and goes on to cite statistics concerning that problem and the accidents it causes, including a 1979 study finding that “23% of the operating personnel were ‘problem drinkers.’” Skinner, ante, at 606, and 607, n. 1.

The Court’s opinion in the present case, however, will be searched in vain for real evidence of a real problem that will be solved by urine testing of Customs Service employees. *682Instead, there are assurances that “[t]he Customs Service is our Nation’s first line of defense against one of the greatest problems affecting the health and welfare of our population,” ante, at 668; that “[m]any of the Service’s employees are often exposed to [drug smugglers] and to the controlled substances [they seek] to smuggle into the country,” ante, at 669; that “Customs officers have been the targets of bribery by drug smugglers on numerous occasions, and several have been removed from the Service for accepting bribes and other integrity violations,” ibid,.; that “the Government has a compelling interest in ensuring that front-line interdiction personnel are physically fit, and have unimpeachable integrity and judgment,” ante, at 670; that the “national interest in self-protection could be irreparably damaged if those charged with safeguarding it were, because of their own drug use, unsympathetic to their mission of interdicting narcotics,” ibid.; and that “the public should not bear the risk that employees who may suffer from impaired perception and judgment will be promoted to positions where they may need to employ deadly force,” ante, at 671. To paraphrase Churchill, all this contains much that is obviously true, and much that is relevant; unfortunately, what is obviously true is not relevant, and what is relevant is not obviously true. The only pertinent points, it seems to me, are supported by nothing but speculation, and not very plausible speculation at that. It is not apparent to me that a Customs Service employee who uses drugs is significantly more likely to be bribed by a drug smuggler, any more than a Customs Service employee who wears diamonds is significantly more likely to be bribed by a diamond smuggler — unless, perhaps, the addiction to drugs is so severe, and requires so much money to maintain, that it would be detectable even without benefit of a urine test. Nor is it apparent to me that Customs officers who use drugs will be appreciably less “sympathetic” to their drug-interdiction mission, any more than police officers who exceed the speed limit in their private cars are appreciably less *683sympathetic to their mission of enforcing the traffic laws. (The only difference is that the Customs officer’s individual efforts, if they are irreplaceable, can theoretically affect the availability of his own drug supply — a prospect so remote as to be an absurd basis of motivation.) Nor, finally, is it apparent to me that urine tests will be even marginally more effective in preventing gun-carrying agents from risking “impaired perception and judgment” than is their current knowledge that, if impaired, they may be shot dead in unequal combat with unimpaired smugglers — unless, again, their addiction is so severe that no urine test is needed for detection.

What is absent in the Government’s justifications — notably absent, revealingly absent, and as far as I am concerned dis-positively absent —is the recitation of even a single instance in which any of the speculated horribles actually occurred: an instance, that is, in which the cause of bribetaking, or of poor aim, or of unsympathetic law enforcement, or of compromise of classified information, was drug use. Although the Court points out that several employees have in the past been removed from the Service for accepting bribes and other integrity violations, and that at least nine officers have died in the line of duty since 1974, ante, at 669, there is no indication whatever that these incidents were related to drug use by Service employees. Perhaps concrete evidence of the severity of a problem is unnecessary when it is so well known that courts can almost take judicial notice of it; but that is surely not the case here. The Commissioner of Customs himself has stated that he “believe[s] that Customs is largely drug-free,” that “[t]he extent of illegal drug use by Customs employees was not the reason for establishing this program,” and that he “hope[s] and expect[s] to receive reports of very few positive findings through drug screening.” App. 10, 15. The test results have fulfilled those hopes and expectations. According to the Service’s counsel, out of 3,600 employees *684tested, no more than 5 tested positive for drugs. See ante, at 673.

The Court’s response to this lack of evidence is that “[t]here is little reason to believe that American workplaces are immune from [the] pervasive social problem” of drug abuse. Ante, at 674. Perhaps such a generalization would suffice if the workplace at issue could produce such catastrophic social harm that no risk whatever is tolerable — the secured areas of a nuclear power plant, for example, see Rushton v. Nebraska Public Power District, 844 F. 2d 562 (CA8 1988). But if such a generalization suffices to justify demeaning bodily searches, without particularized suspicion, to guard against the bribing or blackmailing of a law enforcement agent, or the careless use of a firearm, then the Fourth Amendment has become frail protection indeed. In Skinner, Bell, T. L. O., and Martinez-Fuerte, we took pains to establish the existence of special need for the search or seizure— a need based not upon the existence of a “pervasive social problem” combined with speculation as to the effect of that problem in the field at issue, but rather upon well-known or well-demonstrated evils in that field, with well-known or well-demonstrated consequences. In Skinner, for example, we pointed to a long history of alcohol abuse in the railroad industry, and noted that in an 8-year period 45 train accidents and incidents had occurred because of alcohol- and drug-impaired railroad employees, killing 34 people, injuring 66, and causing more than $28 million in property damage. Ante, at 608. In the present case, by contrast, not only is the Customs Service thought to be “largely drug-free,” but the connection between whatever drug use may exist and serious social harm is entirely speculative. Except for the fact that the search of a person is much more intrusive than the stop of a car, the present case resembles Delaware v. Prouse, 440 U. S. 648 (1979), where we held that the Fourth Amendment prohibited random stops to check drivers’ licenses and motor vehicle registrations. The contribution of this practice to highway *685safety, we concluded, was “marginal at best” since the number of licensed drivers that must be stopped in order to find one unlicensed one “will be large indeed.” Id., at 660.

Today’s decision would be wrong, but at least of more limited effect, if its approval of drug testing were confined to that category of employees assigned specifically to drug interdiction duties. Relatively few public employees fit that description. But in extending approval of drug testing to that category consisting of employees who carry firearms, the Court exposes vast numbers of public employees to this needless indignity. Logically, of course, if those who carry guns can be treated in this fashion, so can all others whose work, if performed under the influence of drugs, may endanger others — automobile drivers, operators of other potentially dangerous equipment, construction workers, school crossing guards. A similarly broad scope attaches to the Court’s approval of drug testing for those with access to “sensitive information.”1 Since this category is not limited to *686Service employees with drug interdiction duties, nor to “sensitive information” specifically relating to drug traffic, today’s holding apparently approves drug testing for all federal employees with security clearances — or, indeed, for all federal employees with valuable confidential information to impart. Since drug use is not a particular problem in the Customs Service, employees throughout the Government are no less likely to violate the public trust by taking bribes to feed their drug habit, or by yielding to blackmail. Moreover, there is no reason why this super-protection against harms arising from drug use must be limited to public employees; a law requiring similar testing of private citizens who use dangerous instruments such as guns or cars, or who have access to classified information, would also be constitutional.

There is only one apparent basis that sets the testing at issue here apart from all these other situations — but it is not a basis upon which the Court is willing to rely. I do not believe for a minute that the driving force behind these drug-testing rules was any of the feeble justifications put forward by counsel here and accepted by the Court. The only plausible explanation, in my view, is what the Commissioner himself offered in the concluding sentence of his memorandum to Customs Service employees announcing the program: “Implementation of the drug screening program would set an important example in our country’s struggle with this most serious threat to our national health and security.” App. 12. Or as respondent’s brief to this Court asserted: “[I]f a law enforcement agency and its employees do not take the law seriously, neither will the public on which the agency’s effectiveness depends.” Brief for Respondent 36. What better way to show that the Government is serious about its “war on drugs” than to subject its employees on the front line of that war to this invasion of their privacy and affront to their dignity? To be sure, there is only a slight chance that it will prevent some serious public harm resulting from Service employee drug use, but it will show to the world that the *687Service is “clean,” and — most important of all — will demonstrate the determination of the Government to eliminate this scourge of our society! I think it obvious that this justification is unacceptable; that the impairment of individual liberties cannot be the means of making a point; that symbolism, even symbolism for so worthy a cause as the abolition of unlawful drugs, cannot validate an otherwise unreasonable search.

There is irony in the Government’s citation, in support of its position, of Justice Brandéis’ statement in Olmstead v. United States, 277 U. S. 438, 485 (1928) that “[f]or good or for ill, [our Government] teaches the whole people by its example.” Brief for Respondent 36. Brandéis was there dissenting from the Court’s admission of evidence obtained through an unlawful Government wiretap. He was not praising the Government’s example of vigor and enthusiasm in combatting crime, but condemning its example that “the end justifies the means,” 277 U. S., at 485. An even more apt quotation from that famous Brandéis dissent would have been the following:

“[I]t is . . . immaterial that the intrusion was in aid of law enforcement. Experience should teach us to be most on our guard to protect liberty when the Government’s purposes are beneficent. Men born to freedom are naturally alert to repel invasion of their liberty by evil-minded rulers. The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well-meaning but without understanding.” Id., at 479.

Those who lose because of the lack of understanding that begot the present exercise in symbolism are not just the Customs Service employees, whose dignity is thus offended, but all of us — who suffer a coarsening of our national manners that ultimately give the Fourth Amendment its content, and who become subject to the administration of federal officials whose respect for our privacy can hardly be greater than the small respect they have been taught to have for their own.

Justice Ginsburg

delivered the opinion of the Court.

The Fourth Amendment requires government to respect “[t]he right of the people to be secure in their persons . . . against unreasonable searches and seizures.” This restraint on government conduct generally bars officials from undertaking a search or seizure absent individualized suspicion. Searches conducted without grounds for suspicion of particular individuals have been upheld, however, in “certain limited circumstances.” See Treasury Employees v. Von Raab, 489 U. S. 656, 668 (1989). These circumstances include brief stops for questioning or observation at a fixed Border Patrol checkpoint, United States v. Martinez-Fuerte, 428 U. S. 543, 545-550, 566-567 (1976), or at a sobriety checkpoint, Michigan Dept. of State Police v. Sitz, 496 U. S. 444, 447, 455 (1990), and administrative inspections in “closely regulated” businesses, New York v. Burger, 482 U. S. 691, 703-704 (1987).

Georgia requires candidates for designated state offices to certify that they have taken a drug test and that the test result was negative. Ga. Code Ann. §21-2-140 (1993) (hereinafter §21-2-140). We confront in this case the question whether that requirement ranks among the limited circumstances in which suspicionless searches are warranted. Relying on this Court's precedents sustaining drug-testing *309programs for student athletes, customs employees, and railway employees, see Vernonia School Dist. 47J v. Acton, 515 U. S. 646, 650, 665-666 (1995) (random drug testing of students who participate in interscholastic sports); Von Raab, 489 U. S., at 659 (drug tests for United States Customs Service employees who seek transfer or promotion to certain positions); Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 608-613 (1989) (drug and alcohol tests for railway employees involved in train accidents and for those who violate particular safety rules), the United States Court of Appeals for the Eleventh Circuit judged Georgia’s law constitutional. We reverse that judgment. Georgia’s requirement that candidates for state office pass a drug test, we hold, does not fit within the closely guarded category of constitutionally permissible suspicionless searches.

I

The prescription at issue, approved by the Georgia Legislature in 1990, orders that “[ejach candidate seeking to qualify for nomination or election to a state office shall as a condition of such qualification be required to certify that such candidate has tested negative for illegal drugs.” §21 — 2— 140(b). Georgia was the first, and apparently remains the only, State to condition candidacy for state office on a drug test.

Under the Georgia statute, to qualify for a place on the ballot, a candidate must present a certificate from a state-approved laboratory, in a form approved by the Secretary of State, reporting that the candidate submitted to a urinalysis drug test within 30 days prior to qualifying for nomination or election and that the results were negative. § 21 — 2— 140(c). The statute lists as “[ijllegal drug[s]”: marijuana, cocaine, opiates, amphetamines, and phencyclidines. § 21-2-140(a)(3). The designated state offices are: “the Governor, Lieutenant Governor, Secretary of State, Attorney General, State School Superintendent, Commissioner of Insurance, *310Commissioner of Agriculture, Commissioner of Labor, Justices of the Supreme Court, Judges of the Court of Appeals, judges of the superior courts, district attorneys, members of the General Assembly, and members of the Public Service Commission.” § 21-2-140(a)(4).

Candidate drug tests are to be administered in a manner consistent with the United States Department of Health and Human Services Guidelines, 53 Fed. Reg. 11979-11989 (1988), or other professionally valid procedures approved by Georgia’s Commissioner of Human Resources. See § 21-2-140(a)(2). A candidate may provide the test specimen at a laboratory approved by the State, or at the office of the candidate’s personal physician, see App. 4-5 (Joint Statement of Undisputed Facts). Once a urine sample is obtained, an approved laboratory determines whether any of the five specified illegal drugs are present, id., at 5; §21-2-140(c), and prepares a certificate reporting the test results to the candidate.

Petitioners were Libertarian Party nominees in 1994 for state offices subject to the requirements of §21-2-140. The Party nominated Walker L. Chandler for the office of Lieutenant Governor, Sharon T. Harris for the office of Commissioner of Agriculture, and James D. Walker for the office of member of the General Assembly. In May 1994, about one month before the deadline for submission of the certificates required by §21-2-140, petitioners Chandler, Harris, and Walker filed this action in the United States District Court for the Northern District of Georgia. They asserted, inter alia, that the drug tests required by §21-2-140 violated their rights under the First, Fourth, and Fourteenth Amendments to the United States Constitution. Naming as defendants Governor Zell D. Miller and two other state officials involved in the administration of §21-2-140, petitioners requested declaratory and injunctive relief barring enforcement of the statute.

*311In June 1994, the District Court denied petitioners’ motion for a preliminary injunction. Stressing the importance of the state offices sought and the relative unintrusiveness of the testing procedure, the court found it unlikely that petitioners would prevail on the merits of their claims. App. to Pet. for Cert. 5B. Petitioners apparently submitted to the drug tests, obtained the certificates required by § 21-2-140, and appeared on the ballot. See Tr. of Oral Arg. 5. After the 1994 election, the parties jointly moved for the entry of final judgment on stipulated facts. In January 1995, the District Court entered final judgment for respondents.

A divided Eleventh Circuit panel affirmed. 73 F. 3d 1543 (1996). It is settled law, the court accepted, that the drug tests required by the statute rank as searches. But, as was true of the drug-testing programs at issue in Skinner and Von Raab, the court reasoned, §21-2-140 serves “special needs,” interests other than the ordinary needs of law enforcement. The court therefore endeavored to “ ‘balance the individual’s privacy expectations against the Government’s interests to determine whether it [was] impractical to require a warrant or some level of individualized suspicion in the particular context.’” 73 F. 3d, at 1545 (quoting Von Raab, 489 U. S., at 665-666).

Examining the state interests involved, the court acknowledged the absence of any record of drug abuse by elected officials in Georgia. Nonetheless, the court observed, “[t]he people of Georgia place in the trust of their elected officials ... their liberty, their safety, their economic well-being, [and] ultimate responsibility for law enforcement.” 73 F. 3d, at 1546. Consequently, “those vested with the highest executive authority to make public policy in general and frequently to supervise Georgia’s drug interdiction efforts in particular must be persons appreciative of the perils of drug use.” Ibid. The court further noted that “[t]he nature of high public office in itself demands the highest levels of honesty, clear-sightedness, and clear-thinking.” Ibid. Re*312citing responsibilities of the offices petitioners sought, the Court of Appeals perceived those “positions [as] particularly susceptible to the ‘risks of bribery and blackmail against which the Government is entitled to guard.’ ” Ibid, (quoting Von Raab, 489 U. S., at 674).

Turning to petitioners’ privacy interests, the Eleventh Circuit emphasized that the tests could be conducted in the office of the candidate’s private physician, making the “intrusion here . . . even less than that approved in Von Raab." 73 F. 3d, at 1547. The court also noted the statute’s reference to federally approved drug-testing guidelines. Ibid. The drug test itself would reveal only the presence or absence of indicia of the use of particular drugs, and not any other information about the health of the candidate. Furthermore, the candidate would control release of the test results: Should the candidate test positive, he or she could forfeit the opportunity to run for office, and in that event, nothing would be divulged to law enforcement officials. Ibid. Another consideration, the court said, is the reality that “candidates for high office must expect the voters to demand some disclosures about their physical, emotional, and mental fitness for the position.” Ibid. Concluding that the State’s interests outweighed the privacy intrusion caused by the required certification, the court held the statute, as applied to petitioners, not inconsistent' with the Fourth and Fourteenth Amendments. Ibid. 1

Judge Barkett dissented. In her view, a balance of the State’s and candidates’ interests was not appropriate, for the State had failed to establish a special governmental need for the regime. “There is nothing so special or immediate about the generalized governmental interests involved here,” she observed, “as to warrant suspension of the Fourth *313Amendment’s requirement of individualized suspicion for searches and seizures.” Id., at 1551.

We granted the petition for certiorari, 518 U. S. 1057 (1996), and now reverse.2

II

We begin our discussion of this case with an uncontested point: Georgia’s drug-testing requirement, imposed by law and enforced by state officials, effects a search within the meaning of the Fourth and Fourteenth Amendments. See Skinner, 489 U. S., at 617; Tr. of Oral Arg. 36; Brief for United States as Amicus Curiae Í0 (collection and testing of urine to meet Georgia’s certification statute “constitutes a search subject to the demands of the Fourth Amendment” (internal quotation marks omitted)). As explained in Sjkin-ner, government-ordered “collection and testing of urine intrudes upon expectations of privacy that society has long recognized as reasonable.” 489 U. S., at 617. Because “these intrusions [are] searches under the Fourth Amendment,” ibid., we focus on the question: Are the searches reasonable?

To be reasonable under the Fourth Amendment, a search ordinarily must be based on individualized suspicion of wrongdoing. See Vernonia, 515 U. S., at 652-653. But particularized exceptions to the main rule are sometimes warranted based on “special needs, beyond the normal need for law enforcement.” Skinner, 489 U. S., at 619 (internal *314quotation marks omitted). When such “special needs”— concerns other than crime detection — are alleged in justification of a Fourth Amendment intrusion, courts must undertake a context-specific inquiry, examining closely the competing private and public interests advanced by the parties. See Von Raab, 489 U. S., at 665-666; see also id., at 668. As Skinner stated: “In limited circumstances, where the privacy interests implicated by the search are minimal, and where an important governmental interest furthered by the intrusion would be placed in jeopardy by a requirement of individualized suspicion, a search may be reasonable despite the absence of such suspicion.” 489 U. S., at 624.

In evaluating Georgia’s ballot-access, drug-testing statute — a measure plainly not tied to individualized suspicion— the Eleventh Circuit sought to “ ‘balance the individual’s privacy expectations against the [State’s] interests,’ ” 73 F. 3d, at 1545 (quoting Von Raab, 489 U. S., at 665), in line with our precedents most immediately in point: Skinner, Von Raab, and Vernonia. We review those decisions before inspecting Georgia’s law.

A

Skinner concerned Federal Railroad Administration (FRA) regulations that required blood and urine tests of rail employees involved in train accidents; the regulations also authorized railroads to administer breath and urine tests to employees who violated certain safety rules. 489 U. S., at 608-612. The FRA adopted the drug-testing program in response to evidence of drug and alcohol abuse by some railroad employees, the obvious safety hazards posed by such abuse, and the documented link between drug- and alcohol-impaired employees and the incidence of train accidents. Id., at 607-608. Recognizing that the urinalysis tests, most conspicuously, raised evident privacy concerns, the Court noted two offsetting considerations: First, the regulations reduced the intrusiveness of the collection process, id., at 626; *315and, more important, railway employees, “by reason of their participation in an industry that is regulated pervasively to ensure safety,” had diminished expectations of privacy, id., at 627.

“[Surpassing safety interests,” the Court concluded, warranted the FRA testing program. Id., at 634. The drug tests could deter illegal drug use by railroad employees, workers positioned to “cause great human loss before any signs of impairment become noticeable to supervisors.” Id., at 628. The program also helped railroads to obtain invaluable information about the causes of major train accidents. See id., at 630. Testing without a showing of individualized suspicion was essential, the Court explained, if these vital interests were to be served. See id., at 628. Employees could not forecast the timing of an accident or a safety violation, events that would trigger testing. The employee’s inability to avoid detection simply by staying drug free at a prescribed test time significantly enhanced the deterrent effect of the program. See ibid. Furthermore, imposing an individualized suspicion requirement for a drug test in the chaotic aftermath of a train accident would seriously impede an employer’s ability to discern the cause of the accident; indeed, waiting until suspect individuals could be identified “likely would result in the loss or deterioration of the evidence furnished by the tests.” Id., at 631.

In Von Raab, the Court sustained a United States Customs Service program that made drug tests a condition of promotion or transfer to positions directly involving drug interdiction or requiring the employee to carry a firearm. 489 U. S., at 660-661, 667-677.3 While the Service’s regime was *316not prompted by a demonstrated drug abuse problem, id., at 660, it was developed for an agency with an “almost unique mission,” id., at 674, as the “first line of defense” against the smuggling of illicit drugs into the United States, id., at 668. Work directly involving drug interdiction and posts that require the employee to carry a firearm pose grave safety threats to employees who hold those positions, and also expose them to large amounts of illegal narcotics and to persons engaged in crime; illicit drug users in such high-risk positions might be unsympathetic to the Service’s mission, tempted by bribes, or even threatened with blackmail. See id., at 668-671. The Court held that the Government had a “compelling” interest in assuring that employees placed in these positions would not include drug users. See id., at 670-671. Individualized suspicion would not work in this setting, the Court determined, because it was “not feasible to subject [these] employees and their work product to the kind of day-to-day scrutiny that is the norm in more traditional office environments.” Id., at 674.

Finally, in Vernonia, the Court sustained a random drug-testing program for-high school students engaged in interscholastic athletic competitions. The program’s context was critical, for a local government bears large “responsibilities, under a public school system, as guardian and tutor of children entrusted to its care.” 515 U. S., at 665. An “immediate crisis,” id., at 663, caused by “a sharp increase in drug use” in the school district, id., at 648, sparked installation of the program. District Court findings established that student athletes were not only “among the drug users,” they were “leaders of the drug culture.” Id., at 649. Our decision noted that “‘students within the school environment have a lesser expectation of privacy than members of the population generally.’ ” Id., at 657 (quoting New Jersey v. *317 T. L. O., 469 U. S. 325, 348 (1985) (Powell, J., concurring)). We emphasized the importance of deterring drug use by schoolchildren and the risk of injury a drug-using student athlete east on himself and those engaged with him on the playing field. See Vernonia, 515 U. S., at 662.

B

Respondents urge that the precedents just examined are not the sole guides for assessing the constitutional validity of the Georgia statute. The “special needs” analysis, they contend, must be viewed through a different lens because § 21-2-140 implicates Georgia’s sovereign power, reserved to it under the Tenth Amendment, to establish qualifications for those who seek state office. Respondents rely on Gregory v. Ashcroft, 501 U. S. 452 (1991), which upheld against federal statutory and Equal Protection Clause challenges Missouri’s mandatory retirement age of 70 for state judges. The Court found this age classification reasonable and not barred by the federal legislation. See id., at 473. States, Gregory reaffirmed, enjoy wide latitude to establish conditions of candidacy for state office, but in setting such conditions, they may not disregard basic constitutional protections. See id., at 463; McDaniel v. Paty, 435 U. S. 618 (1978) (invalidating state provision prohibiting members of clergy from serving as delegates to state constitutional convention); Communist Party of Ind. v. Whitcomb, 414 U. S. 441 (1974) (voiding loyalty oath as a condition of ballot access); Bond v. Floyd, 385 U. S. 116 (1966) (Georgia Legislature could not exclude elected representative on ground that his antiwar statements cast doubt on his ability to take an oath). We are aware of no precedent suggesting that a State’s power to establish qualifications for state offices — any more than its sovereign power to prosecute crime — diminishes the constraints on state action imposed by the Fourth Amendment. We therefore reject respondents’ invitation to apply in this case a framework extraordinarily deferential to state meas*318ures setting conditions of candidacy for state office. Our guides remain Skinner, Von Raab, and Vernonia.

Turning to those guides, we note, first, that the testing method the Georgia statute describes is relatively noninvasive; therefore, if the “special needs” showing had been made, the State could not be faulted for excessive intrusion. Georgia’s statute invokes the drug-testing guidelines applicable to the federal programs upheld in Skinner and Von Raab. See Brief for United States as Amicus Curiae 20-21; Von Raab, 489 U. S., at 661-662, n. 1. The State permits a candidate to provide the urine specimen in the office of his or her private physician; and the results of the test are given first to the candidate, who controls further dissemination of the report. Because the State has effectively limited the invasiveness of the testing procedure, we concentrate on the core issue: Is the certification requirement warranted by a special need?

Our precedents establish that the proffered special need for drug testing must be substantial — important enough to override the individual’s acknowledged privacy interest, sufficiently vital to suppress the Fourth Amendment’s normal requirement of individualized suspicion. See supra, at 313-317 and this page. Georgia has failed to show, in justification of § 21-2-140, a special need of that kind.

Respondents’ defense of the statute rests primarily on the incompatibility of unlawful drug use with holding high state office. The statute is justified, respondents contend, because the use of illegal drugs draws into question an official’s judgment and integrity; jeopardizes the discharge of public functions, including antidrug law enforcement efforts; and undermines public confidence and trust in elected officials. Brief for Respondents 11-18. The statute, according to respondents, serves to deter unlawful drug users from becoming candidates and thus stops them from attaining high state office. Id., at 17-18. Notably lacking in respondents’ pres*319entation is any indication of a concrete danger demanding departure from the Fourth Amendment’s main rule.

Nothing in the record hints that the hazards respondents broadly describe are real and not simply hypothetical for Georgia’s polity. The statute was not enacted, as counsel for respondents readily acknowledged at oral argument, in response to any fear or suspicion of drug use by state officials:

“QUESTION: Is there any indication anywhere in this record that Georgia has a particular problem here with State officeholders being drug abusers?

“[COUNSEL FOR RESPONDENTS]: No, there is no such evidence, [and] to be frank, there is no such problem as we sit here today.” Tr. of Oral Arg. 32.

See also id., at 31 (counsel for respondents affirms absence of evidence that state officeholders in Georgia have drug problems). A demonstrated problem of drug abuse, while not in all cases necessary to the validity of a testing regime, see Von Raab, 489 U. S., at 673-675, would shore up an assertion of special need for a suspicionless general search program. Proof of unlawful drug use may help to clarify — and to substantiate — the precise hazards posed by such use. Thus, the evidence of drug and alcohol use by railway employees engaged in safety-sensitive tasks in Skinner, see 489 U. S., at 606-608, and the immediate crisis prompted by a sharp rise in students’ use of unlawful drugs in Vernonia, see 515 U. S., at 662-663, bolstered the Government’s and school officials’ arguments that drug-testing programs were warranted and appropriate.

In contrast to the effective testing regimes upheld in Skinner, Von Raab, and Vernonia, Georgia’s certification requirement is not well designed to identify candidates who violate antidrug laws. Nor is the scheme a credible means to deter illicit drug users from seeking election to state office. The test date — to be scheduled by the candidate anytime within *32030 days prior to qualifying for a place on the ballot — is no secret. As counsel for respondents acknowledged at oral argument, users of illegal drugs, save for those prohibitively addicted, could abstain for a pretest period sufficient to avoid detection. See Tr. of Oral Arg. 44-46.4 Even if we indulged respondents’ argument that one purpose of §21-2-140 might be to detect those unable so to abstain, see id., at 46, respondents have not shown or argued that such persons are likely to be candidates for public office in Georgia. Moreover, respondents have offered no reason why ordinary law enforcement methods would not suffice to apprehend such addicted individuals, should they appear in the limelight of a public stage. Section 21-2-140, in short, is not needed and cannot work to ferret out lawbreakers, and respondents barely attempt to support the statute on that ground.

Respondents and the United States as amicus curiae rely most heavily on our decision in Von Raab, which sustained a drug-testing program for Customs Service officers prior to promotion or transfer to certain high-risk positions, despite the absence of any documented drug abuse problem among Service employees. 489 U. S., at 660; see Brief for Respondents 12-14; Brief for United States as Amicus Curiae 18; see also 73 F. 3d, at 1646. The posts in question in Von Raab directly involved drug interdiction or otherwise required the Service member to carry a firearm. See 489 U. S., at 670 (“Government has a compelling interest in ensuring that front-line interdiction personnel are physically fit, and have unimpeachable integrity and judgment.”); id., at 670-671 (“[T]he public should not bear the risk that employees who may suffer from impaired perception and judgment will be promoted to positions where they may need to employ deadly force.”).

*321Hardly a decision opening broad vistas for suspicionless searches, Von Raab must be read in its unique context. As the Customs Service reported in announcing the testing program: “Customs employees, more than any other Federal workers, are routinely exposed to the vast network of organized crime that is inextricably tied to illegal drug use.” National Treasury Employees Union v. Von Raab, 816 F. 2d 170, 173 (CA5 1987) (internal quotation marks omitted), aff’d in part, vacated in part, 489 U. S. 656 (1989). We stressed that “[d]rug interdiction ha[d] become the agency’s primary enforcement mission,” id., at 660, and that the employees in question would have “access to vast sources of valuable contraband,” id., at 669. Furthermore, Customs officers “ha[dj been the targets of bribery by drug smugglers on numerous occasions,” and several had succumbed to the temptation. Ibid.

Respondents overlook a telling difference between Von Raab and Georgia’s candidate drug-testing program. In Von Raab it was “not feasible to subject employees [required to carry firearms or concerned with interdiction of controlled substances] and their work product to the kind of day-to-day scrutiny that is the norm in more traditional office environments.” Id., at 674. Candidates for public office, in contrast, are subject to relentless scrutiny — by their peers, the public, and the press. Their day-to-day conduct attracts attention notably beyond the norm in ordinary work environments.

What is left, after close review of Georgia’s scheme, is the image the State seeks to project. By requiring candidates for public office to submit to drug testing, Georgia displays its commitment to the struggle against drug abuse. The suspicionless tests, according to respondents, signify that candidates, if elected, will be fit to serve their constituents free from the influence of illegal drugs. But Georgia asserts no evidence of a drug problem among the State’s elected officials, those officials typically do not perform high-risk, *322safety-sensitive tasks, and the required certification immediately aids no interdiction effort. The need revealed, in short, is symbolic, not “special,” as that term draws meaning from our case law.

In Von Raab, the Customs Service had defended its officer drug-testing program in part as a way to demonstrate the agency’s commitment to enforcement of the law. See Brief for United States in Treasury Employees v. Von Raab, O. T. 1988, No. 86-1879, pp. 35-36. The Von Raab Court, however, did not rely on that justification. Indeed, if a need of the “set a good example” genre were sufficient to overwhelm a Fourth Amendment objection, then the care this Court took to explain why the needs in Skinner, Von Raab, and Vernonia ranked as “special” wasted many words in entirely unnecessary, perhaps even misleading, elaborations.

In a pathmarking dissenting opinion, Justice Brandéis recognized the importance of teaching by example: “Our Government is the potent, the omnipresent teacher. For good or for ill, it teaches the whole people by its example.” Olmstead v. United States, 277 U. S. 438, 485 (1928). Justice Brandéis explained in Olmstead why the Government set a bad example when it introduced in a criminal proceeding evidence obtained through an unlawful Government wiretap:

“[I]t is . . . immaterial that the intrusion was in aid of law enforcement. Experience should teach us to be most on our guard to protect liberty when the Government’s purposes are beneficent. Men born to freedom are naturally alert to repel invasion of their liberty by evil-minded rulers. The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well-meaning but without understanding.” Id., at 479.

However well meant, the candidate drug test Georgia has devised diminishes personal privacy for a symbol’s sake. The Fourth Amendment shields society against that state action.

*323III

We note, finally, matters this opinion does not treat. Georgia’s singular drug test for candidates is not part of a medical examination designed to provide certification of a candidate’s general health, and we express no opinion on such examinations. Nor do we touch on financial disclosure requirements, which implicate different concerns and procedures. See, e. g., Barry v. City of New York, 712 F. 2d 1554 (CA2 1983) (upholding city’s financial disclosure law for elected and appointed officials, candidates for city office, and certain city employees); Plante v. Gonzalez, 575 F. 2d 1119 (CA5 1978) (upholding Florida’s financial disclosure requirements for certain public officers, candidates, and employees). And we do not speak to drug testing in the private sector, a domain unguarded by Fourth Amendment constraints. See United States v. Jacobsen, 466 U. S. 109, 113 (1984).

We reiterate, too, that where the risk to public safety is substantial and real, blanket suspicionless searches calibrated to the risk may rank as “reasonable” — for example, searches now routine at airports and at entrances to courts and other official buildings. See Von Raab, 489 U. S., at 674-676, and n. 3. But where, as in this case, public safety is not genuinely in jeopardy, the Fourth Amendment precludes the suspicionless search, no matter how conveniently arranged.

* * *

For the reasons stated, the judgment of the Court of Appeals for the Eleventh Circuit is

Reversed.

Chief Justice Rehnquist,

dissenting.

I fear that the novelty of this Georgia law has led the Court to distort Fourth Amendment doctrine in order to strike it down. The Court notes, impliedly turning up its nose, that “Georgia was the first, and apparently remains the only, State to condition candidacy for state office on a drug *324test.” Ante, at 309. But if we are to heed the oft-quoted words of Justice Brandéis in his dissent in New State Ice Co. v. Liebmann, 285 U. S. 262, 311 (1932) — “[i]t is one of the happy incidents of the federal system that a single courageous State may, if its citizens choose, serve as a laboratory; and try novel social and economic experiments without risk to the rest of the country” — novelty itself is not a vice. These novel experiments, of course, must comply with the United States Constitution; but their mere novelty should not be a strike against them.

Few would doubt that the use of illegal drugs and abuse of legal drugs is one of the major problems of our society. Cases before this Court involving drug use extend to numerous occupations — railway employees, Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602 (1989), Border Patrol officers, Treasury Employees v. Von Raab, 489 U. S. 656 (1989), high school students, Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), and machine operators, Paperworkers v. Misco, Inc., 484 U. S. 29 (1987). It would take a bolder person than I to say that such widespread drug usage could never extend to candidates for public office such as Governor of Georgia. The Court says that “[n]othing in the record hints that the hazards respondents broadly describe are real and not simply hypothetical for Georgia’s polity.” Ante, at 319. But surely the State need not wait for a drug addict, or one inclined to use drugs illegally, to run for or actually become Governor before it installs a prophylactic mechanism. We held as much in Von Raab:

“First, petitioners argue that the program is unjustified because it is not based on a belief that testing will reveal any drug use by covered employees. In pressing this argument, petitioners point out that the Service’s testing scheme was not implemented in response to any perceived drug problem among Customs employees ....

“Petitioners’ first contention evinces an unduly narrow view of the context in which the Service’s testing *325program was implemented. Petitioners do not dispute, nor can there be doubt, that drug abuse is one of the most serious problems confronting our society today. There is little reason to believe that American workplaces are immune from this pervasive social problem . . . .” 489 U. S., at 673-674.

The test under the Fourth Amendment, as these cases have held, is whether the search required by the Georgia statute is “reasonable.” Today’s opinion speaks of a “closely guarded” class of permissible suspicionless searches which must be justified by a “special need.” But this term, as used in Skinner and Von Raab and on which the Court now relies, was used in a quite different sense than it is used by the Court today. In Skinner and Von Raab it was used to describe a basis for a search apart from the regular needs of law enforcement, Skinner, supra, at 620; Von Raab, supra, at 669. The “special needs” inquiry as delineated there has not required especially great “importan[ce],” ante, at 318, unless one considers “the supervision of probationers,” or the “operation of a government office,” Skinner, supra, at 620, to be especially “important.” Under our precedents, if there was a proper governmental purpose other than law enforcement, there was a “special need,” and the Fourth Amendment then required the familiar balancing between that interest and the individual’s privacy interest.

Under normal Fourth Amendment analysis, the individual’s expectation of privacy is an important factor in the equation. But here, the Court perversely relies on the fact that a candidate for office gives up so much privacy — “[candidates for public office ... are subject to relentless scrutiny— by their peers, the public, and the press,” ante, at 321 — as a reason for sustaining a Fourth Amendment claim. The Court says, in effect, that the kind of drug test for candidates required by the Georgia law is unnecessary, because the scrutiny to which they are already subjected by reason of their candidacy will enable people to detect any drug use on *326their part. But this is a strange holding, indeed. One might just as easily say that the railroad employees in Skinner, or the Customs officials in Von Raab, would be subjected to the same sort of scrutiny from their fellow employees and their supervisors. But the clear teaching of those cases is that the government is not required to settle for that sort of a vague and uncanalized scrutiny; if in fact preventing persons who use illegal drugs from concealing that fact from the public is a legitimate government interest, these cases indicate that the government may require a drug test.

The privacy concerns ordinarily implicated by urinalysis drug testing are “negligible,” Vernonia, supra, at 658, when the procedures used in collecting and analyzing the urine samples are set up “to reduce the intrusiveness” of the process, Skinner, supra, at 626. Under the Georgia law, the candidate may produce the test specimen at his own doctor’s office, which must be one of the least intrusive types of urinalysis drug tests conceivable. But although the Court concedes this, it nonetheless manages to count this factor against the State, because with this kind of test the person tested will have advance notice of its being given, and will therefore be able to abstain from drug use during the necessary period of time. But one may be sure that if the test were random — and therefore apt to ensnare more users — the Court would then fault it for its intrusiveness. Cf. Von Raab, 489 U. S., at 676, and n. 4.

In Von Raab, we described as “compelling” the Government interest “in ensuring that many of these covered employees do not use drugs even off duty, for such use creates risks of bribery and blackmail against which the Government is entitled to guard.” Id., at 674 (emphasis added). The risks of bribery and blackmail for high-level officials of state government using illegal drugs would seem to be at least as significant as those for off-duty Customs officials. Even more important, however, is our treatment of the third class of tested employees in Von Raab, those who “handle[d] ‘clas-*327sifted’ materials.” The Court relegates this discussion to a footnote, ante, at 315, n. 3, and all but dismisses it. Although the lack of factual development of the record in Von Raab prevented us from determining who “handle[d] ‘classified’ material,” we did consider the weight of the proffered governmental interest:

“We readily agree that the Government has a compelling interest in protecting truly sensitive information from those who, ‘under compulsion of circumstances or for other reasons,... might compromise [such] information.’ Department of Navy v. Egan, 484 U. S. 518, 528 (1988). . . . We also agree that employees who seek promotions to positions where they would handle sensitive information can be required to submit to a urine test under the Service’s screening program, especially if the positions covered under this category require background investigations, medical examinations, or other intrusions that may be expected to diminish their expectations of privacy in respect of a urinalysis test.” 489 U. S., at 677.

Although petitioners might raise questions as to some of the other positions covered by the Georgia statute, there is no question that, at least for positions like Governor and Lieutenant Governor, identical concerns are implicated. In short, when measured through the correct lens of our precedents in this area, the Georgia urinalysis test is a “reasonable” search; it is only by distorting these precedents that the Court is able to reach the result it does.

Lest readers expect the holding of this case to be extended to any other case, the Court notes that the drug test here is not a part of a medical examination designed to provide certification of a candidate’s general health. Ante, at 323. It is all but inconceivable that a case involving that sort of requirement could be decided differently than the present case; the same sort of urinalysis would be involved. The only possible basis for distinction is to say that the State has *328a far greater interest in the candidate’s “general health” than it does with respect to his propensity to use illegal drugs. But this is the sort of policy judgment that surely must be left to legislatures, rather than being announced from on high by the Federal Judiciary.

Nothing in the Fourth Amendment or in any other part of the Constitution prevents a State from enacting a statute whose principal vice is that it may seem misguided or even silly to the Members of this Court. I would affirm the judgment of the Court of Appeals.

Justice Stevens

delivered the opinion of the Court.

In this case, we must decide whether a state hospital’s performance of a diagnostic test to obtain evidence of a patient’s criminal conduct for law enforcement purposes is an *70unreasonable search if the patient has not consented to the procedure. More narrowly, the question is whether the interest in using the threat of criminal sanctions to deter pregnant women from using cocaine can justify a departure from the general rule that an official nonconsensual search is unconstitutional if not authorized by a valid warrant.

I

In the fall of 1988, staff members at the public hospital operated in the city of Charleston by the Medical University of South Carolina (MUSC) became concerned about an apparent increase in the use of cocaine by patients who were receiving prenatal treatment.1 In response to this perceived increase, as of April 1989, MUSC began to order drug screens to be performed on urine samples from maternity patients who were suspected of using cocaine. If a patient tested positive, she was then referred by MUSC staff to the county substance abuse commission for counseling and treatment. However, despite the referrals, the incidence of cocaine use among the patients at MUSC did not appear to change.

Some four months later, Nurse Shirley Brown, the case manager for the MUSC obstetrics department, heard a news broadcast reporting that the police in Greenville, South Carolina, were arresting pregnant users of cocaine on the theory that such use harmed the fetus and was therefore child abuse.2 Nurse Brown discussed the story with MUSC’s general counsel, Joseph C. Good, Jr., who then contacted *71Charleston Solicitor Charles Condon in order to offer MUSC’s cooperation in prosecuting mothers whose children tested positive for drugs at birth.3

After receiving Good’s letter, Solicitor Condon took the first steps in developing the policy at issue in this case. He organized the initial meetings, decided who would participate, and issued the invitations, in which he described his plan to prosecute women who tested positive for cocaine while pregnant. The task force that Condon formed included representatives of MUSC, the police, the Gounty Substance Abuse Commission and the Department of Social Services. Their deliberations led to MUSC’s adoption of a 12-page document entitled “POLICY M-7,” dealing with the subject of “Management of Drug Abuse During Pregnancy.” App. to Pet. for Cert. A-53.

The first three pages of Policy M-7 set forth the procedure to be followed by the hospital staff to “identify/assist pregnant patients suspected of drug abuse.” Id., at A-53 to A-56. The first section, entitled the “Identification of Drug Abusers,” provided that a patient should be tested for co-eaine through a urine drug screen if she met one or more of nine criteria.4 It also stated that a chain of custody should *72be followed when obtaining and testing urine samples, presumably to make sure that the results could be used in subsequent criminal proceedings. The policy also provided for education and referral to a substance abuse clinic for patients who tested positive. Most important, it added the threat of law enforcement intervention that “provided the necessary ‘leverage’ to make the [p]oliey effective.” Brief for Respondents 8. That threat was, as respondents candidly acknowledge, essential to the program’s success in getting women into treatment and keeping them there.

The threat of law enforcement involvement was set forth in two protocols, the first dealing with the identification of drug use during pregnancy, and the seeond with identification of drug use after labor. Under the latter protocol, the police were to be notified without delay and the patient promptly arrested. Under the former, after the initial positive drug test, the police were to be notified (and the patient arrested) only if the patient tested positive for cocaine a see-ond time or if she missed an appointment with a substance abuse counselor.5 In 1990, however, the policy was modified at the behest of the solicitor’s office to give the patient who tested positive during labor, like the patient who tested positive during a prenatal care visit, an opportunity to avoid arrest by consenting to substance abuse treatment.

The last six pages of the policy contained forms for the patients to sign, as well as procedures for the police to follow when a patient was arrested. The policy also prescribed in detail the precise offenses with which a woman could be charged, depending on the stage of her pregnancy. If the pregnancy was 27 weeks or less, the patient was to be charged with simple possession. If it was 28 weeks or more, she was to be charged with possession and distribution to a person under the age of 18 — in this case, the fetus. If she *73delivered "while testing positive for illegal drugs,” she was also to be charged with unlawful neglect of a child. App. to Pet. for Cert. A-62. Under the policy, the police were instructed to interrogate the arrestee in order "to ascertain the identity of the subject who provided illegal drugs to the suspect.” Id., at A-63. Other than the provisions describing the substance abuse treatment to be offered to women who tested positive, the policy made no mention of any change in the prenatal care of such patients, nor did it prescribe any special treatment for the newborns.

HH

Petitioners are 10 women who received obstetrical care at MUSC and who were arrested after testing positive for cocaine. Four of them were arrested during the initial implementation of the policy; they were not offered the opportunity to receive drug treatment as an alternative to arrest. The others were arrested after the policy was modified in 1990; they either failed to comply with the terms of the drug treatment program or tested positive for a second time. Respondents include the city of Charleston, law enforcement officials who helped develop and enforce the policy, and representatives of MUSC.

Petitioners’ complaint challenged the validity of the policy under various theories, including the claim that warrantless and nonconsensual drug tests conducted for criminal investigatory purposes were unconstitutional searches. Respondents advanced two principal defenses to the constitutional claim: (1) that, as a matter of fact, petitioners had consented to the searches; and (2) that, as a matter of law, the searches were reasonable, even absent consent, because they were justified by special non-law-enforcement purposes. The District Court rejected the second defense because the searches in question “were not done by the medical university for independent purposes. [Instead,] the police came in and there was an agreement reached that the positive *74screens would be shared with the police.” App. 1248-1249. Accordingly, the District Court submitted the factual defense to the jury with instructions that required a verdict in favor of petitioners unless the jury found consent.6 The jury found for respondents.

Petitioners appealed, arguing that the evidence was not sufficient to support the jury’s consent finding. The Court of Appeals for the Fourth Circuit affirmed, but without reaching the question of consent. 186 F. 3d 469 (1999). Disagreeing with the District Court, the majority of the appellate panel held that the searches were reasonable as a matter of law under our line of cases recognizing that “special needs” may, in certain exceptional circumstances, justify a search policy designed to serve non-law-enforcement ends.7 *75On the understanding “that MUSC personnel conducted the urine drug screens for medical purposes wholly independent of an intent to aid law enforcement efforts,”id="ref_footnote_1_8">8 id., at 477, the majority applied the balancing test used in Treasury Employees v. Von Raab, 489 U. S. 656 (1989), and Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995), and concluded that the interest in curtailing the pregnancy complications and medical costs associated with maternal cocaine use outweighed what the majority termed a minimal intrusion on the privacy of the patients. In dissent, Judge Blake concluded that the “special needs” doctrine should not apply and *76that the evidence of consent was insufficient to sustain the jury’s verdict. 186 F. 3d, at 487-488.

We granted certiorari, 528 U.S. 1187 (2000), to review the appellate court’s holding on the “special needs” issue. Because we do not reach the question of the sufficiency of the evidence with respect to consent, we necessarily assume for purposes of our decision — as did the Court of Appeals — that the searches were conducted without the informed consent of the patients. We conclude that the judgment should be reversed and the ease remanded for a decision on the consent issue.

Ill

Because MUSO is a state hospital, the members of its staff are government actors, subject to the strictures of the Fourth Amendment. New Jersey v. T. L. O., 469 U. S. 325, 335-337 (1985). Moreover, the urine tests conducted by those staff members were indisputably searches within the meaning of the Fourth Amendment. Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 617 (1989).9 Neither the District Court nor the Court of Appeals concluded that any of the nine criteria used to identify the women to be searched provided either probable cause to believe that they were using cocaine, or even the basis for a reasonable suspicion of such use. Rather, the District Court and the Court of Appeals viewed the case as one involving MUSC’s right *77to conduct searches -without warrants or probable cause.10 Furthermore, given the posture in which the case comes to us, we must assume for purposes of our decision that the tests were performed without the informed consent of the patients.11

Because the hospital seeks to justify its authority to conduct drug tests and to turn the results over to law enforcement agents without the knowledge or consent of the patients, this case differs from the four previous cases in which we have considered whether comparable drug tests “fit within the closely guarded category of constitutionally permissible suspicionless searches.” Chandler v. Miller, 520 U. S. 305, 309 (1997). In three of those cases, we sustained drug tests for railway employees involved in train accidents, Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602 (1989), for United States Customs Service employees seeking promotion to certain sensitive positions, Treasury Employees v. Von Raab, 489 U. S. 656 (1989), and for high school students participating in interseholastic sports, Vernonia School Dist. 47J v. Acton, 515 U. S. 646 (1995). In the fourth case, we struck down such testing for candidates for designated state offices as unreasonable. Chandler v. Miller, 520 U. S. 305 (1997).

*78In each of those cases, we employed a balancing test that weighed the intrusion on the individual’s interest in privacy against the “special needs” that supported the program. As an initial matter, we note that the invasion of privacy in this case is far more substantial than in those eases. In the previous four cases, there was no misunderstanding about the purpose of the test or the potential use of the test results, and there were protections against the dissemination of the results to third parties.12 The use of an adverse test result to disqualify one from eligibility for a particular benefit, such as a promotion or an opportunity to participate in an extracurricular activity, involves a less serious intrusion on privacy than the unauthorized dissemination of such results to third parties. The reasonable expectation of privacy enjoyed by the typical patient undergoing diagnostic tests in a hospital is that the results of those tests will not be shared with nonmedical personnel without her consent. See Brief for American Medical Association as Amicus Curiae 11; Brief for American Public Health Association et al. as Amici Curiae 6,17-19.13 In none of our prior cases was there any intrusion upon that kind of expectation.14

*79The critical difference between those four drug-testing cases and this one, however, lies in the nature of the “special need” asserted as justification for the warrantless searches. In each of those earlier cases, the “special need” that was advanced as a justification for the absence of a warrant or individualized suspicion was one divorced from the State’s general interest in law enforcement.15 This point was em*80phasized both in the majority opinions sustaining the programs in the first three eases,16 as well as in the dissent in the Chandler ease.17 In this case, however, the central and indispensable feature of the policy from its inception was the use of law enforcement to coerce the patients into substance abuse treatment. This fact distinguishes this case from circumstances in which physicians or psychologists, in the *81course of ordinary medical procedures aimed at helping the patient herself, come across information that under rules of law or ethics is subject to reporting requirements, which no one has challenged here. See, e. g., Council on Ethical and Judicial Affairs, American Medical Association, Policy-Finder, Current Opinions E-5.05 (2000) (requiring reporting where “a patient threatens to inflict serious bodily harm to another person or to him or herself and there is a reasonable probability that the patient may carry out the threat”); Ark. Code Ann. § 12-12-602 (1999) (requiring reporting of intentionally inflicted knife or gunshot wounds); Ariz. Rev. Stat. Ann. § 13-3620 (Supp. 2000) (requiring “any ... person having responsibility for the care or treatment of children” to report suspected abuse or neglect to a peace officer or child protection agency).18

Respondents argue in essence that their ultimate purpose — namely, protecting the health of both mother and child — is a beneficent one. In Chandler, however, we did not simply accept the State’s invocation of a “special need.” Instead, we carried out a “close review” of the scheme at issue before concluding that the need in question was not “special,” as that term has been defined in our cases. 520 U.S., at 322. In this case, a review of the M-7 policy plainly reveals that the purpose actually served by the MUSC searches “is ultimately indistinguishable from the general interest in crime control.” Indianapolis v. Edmond, 531 U.S. 32, 44 (2000).

In looking to the programmatic purpose, we consider all the available evidence in order to determine the relevant primary purpose. See, e. g., id., at 45-47. In this case, as *82Judge Blake put it in her dissent below, “it ... is clear from the record that an initial and continuing focus of the policy was on the arrest and prosecution of drug-abusing mothers . . . .” 186 F. 3d, at 484. Tellingly, the document codifying the policy incorporates the police’s operational guidelines. It devotes its attention to the chain of custody, the range of possible criminal charges, and the logistics of police notification and arrests. Nowhere, however, does the document discuss different courses of medical treatment for either mother or infant, aside from treatment for the mother’s addiction.

Moreover, throughout the development and application of the policy, the Charleston prosecutors and police were extensively involved in the day-to-day administration of the policy. Police and prosecutors decided who would receive the reports of positive drug screens and what information would be included with those reports. App. 78-80,145-146,1058-1060. Law enforcement officials also helped determine the procedures to be followed when performing the screens.19 Id., at 1052-1053. See also id., at 26-27,945. In the course of the policy’s administration, they had access to Nurse Brown’s medical files on the women who tested positive, routinely attended the substance abuse team’s meetings, and regularly received copies of team documents discussing the women’s progress. Id., at 122-124, 609-610. Police took pains to coordinate the timing and circumstances of the arrests with MUSC staff, and, in particular, Nurse Brown. Id., at 1057-1058.

While the ultimate goal of the program may well have been to get the women in question into substance abuse treatment *83and off of drugs, the immediate objective of the searches was to generate evidence for law enforcement purposes20 in order to reach that goal.21 The threat of law enforcement *84may ultimately have been intended as a means to an end, but the direct and primary purpose of MUSC’s policy was to ensure the use of those means. In our opinion, this distinction is critical. Because law enforcement involvement always serves some broader social purpose or objective, under respondents’ view, virtually any nonconsensual suspicionless search could be immunized under the special needs doctrine by defining the search solely in terms of its ultimate, rather than immediate, purpose.22 Such an approach is inconsistent with the Fourth Amendment. Given the primary purpose of the Charleston program, which was to use the threat of arrest and prosecution in order to force women into treatment, and given the extensive involvement of law enforcement officials at every stage of the policy, this case simply does not fit within the closely guarded category of "special needs.”23

The fact that positive test results were turned over to the police does not merely provide a basis for distinguishing our prior cases applying the “special needs” balancing approach to the determination of drug use. It also provides an affirmative reason for enforcing the strictures of the Fourth Amendment. While state hospital employees, like other citizens, may have a duty to provide the police with evidence *85of criminal conduct that they inadvertently acquire in the course of routine treatment, when they undertake to obtain such evidence from their patients for the specific purpose of incriminating those patients, they have a special obligation to make sure that the patients are fully informed about their constitutional rights, as standards of knowing waiver require.24 Cf. Miranda v. Arizona, 384 U.S. 436 (1966).

As respondents have repeatedly insisted, their motive was benign rather than punitive. Such a motive, however, cannot justify a departure from Fourth Amendment protections, given the pervasive involvement of law enforcement with the development and application of the MUSC policy. The stark *86and unique fact that characterizes this case is that Policy M-7 was designed to obtain evidence of criminal conduct by the tested patients that would be turned over to the police and that could be admissible in subsequent criminal prosecutions. While respondents are correct that drug abuse both was and is a serious problem, “the gravity of the threat alone cannot be dispositive of questions concerning what means law enforcement officers may employ to pursue a given purpose.” Indianapolis v. Edmond, 531 U. S., at 42-43. The Fourth Amendment’s general prohibition against nonconsen-sual, warrantless, and suspicionless searches necessarily applies to such a policy. See, e. g., Chandler, 520 U. S., at 308; Skinner, 489 U. S., at 619.

Accordingly, the judgment of the Court of Appeals is reversed, and the case is remanded for further proceedings consistent with this opinion.

It is so ordered.

Justice Kennedy,

concurring in the judgment.

I agree that the search procedure in issue cannot be sustained under the Fourth Amendment. My reasons for this conclusion differ somewhat from those set forth by the Court, however, leading to this separate opinion.

I

The Court does not dispute that the search policy at some level serves special needs, beyond those of ordinary law enforcement, such as the need to protect the health of mother and child when a pregnant mother uses cocaine. Instead, the majority characterizes these special needs as the “ultimate goal[s]” of the policy, as distinguished from the policy’s “immediate purpose,” the collection of evidence of drug use, which, the Court reasons, is the appropriate inquiry for the special needs analysis. Ante, at 81-84.

The majority views its distinction between the ultimate goal and immediate purpose of the policy as critical to its *87analysis. Ante, at 83-84. The distinction the Court makes, however, lacle foundation in our special needs cases. All of our special needs cases have turned upon what the majority terms the policy’s ultimate goal. For example, in Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602 (1989), had we employed the majority’s distinction, we would have identified as the relevant need the collection of evidence of drug and alcohol use by railway employees. Instead, we identified the relevant need as “[t]he Government’s interest in regulating the conduct of railroad employees to ensure [railroad] safety.” Id., at 620. In Treasury Employees v. Von Radb, 489 U.S. 656 (1989), the majority’s distinction should have compelled us to isolate the relevant need as the gathering of evidence of drug abuse by would-be drug interdiction officers. Instead, the special needs the Court identified were the necessities “to deter drug use among those eligible for promotion to sensitive positions within the [United States Customs] Service and to prevent the promotion of drug users to those positions.” Id., at 666. In Vernonia School Dist. 17J v. Acton, 515 U. S. 646 (1995), the majority’s distinction would have required us to identify the immediate purpose of gathering evidence of drug use by student-athletes as the relevant “need” for purposes of the special needs analysis. Instead, we sustained the policy as furthering what today’s majority would have termed the policy’s ultimate goal: “[d]eterring drug use by our Nation’s schoolchildren,” and particularly by student-athletes, because “the risk of immediate physical harm to the drug user or those with whom he is playing his sport is particularly high.” Id, at 661-662.

It is unsurprising that in our prior cases we have concentrated on what the majority terms a policy’s ultimate goal, rather than its proximate purpose. By very definition, in almost every case the immediate purpose of a search policy will be to obtain evidence. The circumstance that a particular search, like all searches, is designed to collect evidence *88of some sort reveals nothing about the need it serves. Put a different way, although procuring evidence is the immediate result of a successful search, until today that procurement has not been identified as the special need which justifies the search.

II

While the majority’s reasoning seems incorrect in the respects just discussed, I agree with the Court that the search policy cannot be sustained; As the majority demonstrates and well explains, there was substantial law enforcement involvement in the policy from its inception. None of our special needs precedents has sanctioned the routine inclusion of law enforcement, both in the design of the policy and in using arrests, either threatened or real, to implement the system designed for the special needs objectives. The special needs eases we have decided do not sustain the active use of law enforcement, including arrest and prosecutions, as an integral part of a program which seeks to achieve legitimate, civil objectives. The traditional warrant and probable-cause requirements are waived in our previous cases on the explicit assumption that the evidence obtained in the search is not intended to be used for law enforcement purposes. Most of those tested for drug use under the policy at issue here were not brought into direct contact with law enforcement. This does not change the fact, however, that, as a systemic matter, law enforcement was a part of the implementation of the search policy in each of its applications. Every individual who tested positive was given a letter explaining the policy not from the hospital but from the solicitor’s office. Everyone who tested positive was told a second positive test or failure to undergo substance abuse treatment would result in arrest and prosecution. As the Court holds, the hospital acted, in some respects, as an institutional arm of law enforcement for purposes of the policy. Under these circumstances, while the policy may well have served legitimate needs unrelated to law enforcement, it had *89as well a penal character with a far greater connection to law enforcement than other searches sustained under our special needs rationale.

In my view, it is necessary and prudent to be explicit in explaining the limitations of today’s decision. The beginning point ought to be to acknowledge the legitimacy of the State’s interest in fetal life and of the grave risk to the life and health of the fetus, and later the child, caused by cocaine ingestion. Infants whose mothers abuse cocaine during pregnancy are born with a wide variety of physical and neurological abnormalities. See Chiriboga, Brust, Bateman, & Hauser, Dose-Response Effect of Fetal Cocaine Exposure on Newborn Neurologic Function, 103 Pediatrics 79 (1999) (finding that, compared with unexposed infants, cocaine-exposed infants experienced higher rates of intrauterine growth retardation, smaller head circumference, global hy-pertonia, coarse tremor, and extensor leg posture). Prenatal exposure to cocaine can also result in developmental problems which persist long after birth. See Arendt, Angelopoulos, Salvator, & Singer, Motor Development of Cocaine-exposed Children at Age Two Years, 108 Pediatrics 86 (1999) (concluding that, at two years of age, children who were exposed to cocaine in útero exhibited significantly less fine and gross motor development than those not so exposed); Chasnoff et al., Prenatal Exposure to Cocaine and Other Drugs: Outcome at Four to Six Years, 846 Annals of the New York Academy of Sciences 314, 319-320 (J. Harvey and B. Kosofsky eds. 1998) (finding that 4- to 6-year-olds who were exposed to cocaine in útero exhibit higher instances of depression, anxiety, social, thought, and attention problems, and delinquent and aggressive behaviors than their unexposed counterparts). There can be no doubt that a mother’s ingesting this drug can cause tragic injury to a fetus and a child. There should be no doubt that South Carolina can impose punishment upon an expectant mother who has so little regard for her own unborn that she risks causing him *90or her lifelong damage and suffering. The State, by taking special measures to give rehabilitation and training to expectant mothers with this tragic addiction or weakness, acts well within its powers and its civic obligations.

The holding of the Court, furthermore, does not call into question the validity of mandatory reporting laws such as child abuse laws which require teachers to report evidence of child abuse to the proper authorities, even if arrest and prosecution is the likely result. That in turn highlights the real difficulty. As this case comes to us, and as reputable sources confirm, see K. Farkas, Training Health Care and Human Services Personnel in Perinatal Substance Abuse, in Drug & Alcohol Abuse Reviews, Substance Abuse During Pregnancy and Childhood 13, 27-28 (R. Watson ed. 1995); U. S. Dept, of Health and Human Services, Substance Abuse and Mental Health Services Administration, Pregnant, Substance-Using Women 48 (1993), we must accept the premise that the medical profession can adopt acceptable criteria for testing expectant mothers for cocaine use in order to provide prompt and effective counseling to the mother and to take proper medical steps to protect the child. If prosecuting authorities then adopt legitimate procedures to discover this information and prosecution follows, that ought not to invalidate the testing. One of the ironies of the ease, then, may be that the program now under review, which gives the cocaine user a second and third chance, might be replaced by some more rigorous system. We must, however, take the case as it comes to us; and the use of handcuffs, arrests, prosecutions, and police assistance in designing and implementing the testing and rehabilitation policy cannot be sustained under our previous cases concerning mandatory testing.

Ill

An essential, distinguishing feature of the special needs cases is that the person searched has consented, though the usual voluntariness analysis is altered because adverse con*91sequences (e. g., dismissal from employment or disqualification from playing on a high school sports team) will follow from refusal. The person searched has given consent, as defined to take into account that the consent was not voluntary in the full sense of the word. See Skinner, 489 U. S., at 615; Von Raab, 489 U. S., at 660-661; Acton, 515 U. S., at 650-651. The consent, and the circumstances in which it was given, bear upon the reasonableness of the whole special needs program.

Here, on the other hand, the question of consent, even with the special connotation used in the special needs cases, has yet to be decided. Indeed, the Court finds it necessary to take the unreal step of assuming there was no voluntary consent at all. Thus, we have erected a strange world for deciding the case.

My discussion has endeavored to address the permissibility of a law enforcement purpose in this artificial context. The role played by consent might have affected our assessment of the issues. My concurrence in the judgment, furthermore, should not be interpreted as having considered or resolved the important questions raised by Justice Scaiia with reference to whether limits might be imposed on the use of the evidence if in fact it were obtained with the patient’s consent and in the context of the special needs program. Had we the prerogative to discuss the role played by consent, the case might have been quite a different one. All are in agreement, of course, that the Court of Appeals will address these issues in further proceedings on remand.

With these remarks, I concur in the judgment.

Justice Scalia,

with whom The Chief Justice and Justice Thomas join as to Part II,

dissenting.

There is always an unappealing aspect to the use of doctors and nurses, ministers of mercy, to obtain incriminating evidence against the supposed objects of their ministration— although here, it is correctly pointed out, the doctors and *92nurses were ministering not just to the mothers but also to the children whom their cooperation with the police was meant to protect. But whatever may be the correct social judgment concerning the desirability of what occurred here, that is not the issue in the present case. The Constitution does not resolve all difficult social questions, but leaves the vast majority of them to resolution by debate and the democratic process — which would produce a decision by the citizens of Charleston, through their elected representatives, to forbid or permit the police action at issue here. The question before us is a narrower one: whether, whatever the desirability of this police conduct, it violates the Fourth Amendment’s prohibition of unreasonable searches and seizures. In my view, it plainly does not.

I

The first step in Fourth Amendment analysis is to identify the search or seizure at issue. What petitioners, the Court, and to a lesser extent the concurrence really object to is not the urine testing, but the hospital’s reporting of positive drug-test results to police. But the latter is obviously not a search. At most it may be a “derivative use of the product of a past unlawful search,” which, of course, “work[s] no new Fourth Amendment wrong” and “presents a question, not of rights, but of remedies.” United States v. Calandra, 414 U. S. 338, 354 (1974). There is only one act that could conceivably be regarded as a search of petitioners in the present case: the taking of the urine sample. I suppose the testing of that urine for traces of unlawful drugs could be considered a search of sorts, but the Fourth Amendment protects only against searches of citizens’ “persons, houses, papers, and effects”; and it is entirely unrealistic to regard urine as one of the “effects” (i. e., part of the property) of the person who has passed and abandoned it. Cf. California v. Greenwood, 486 U. S. 35 (1988) (garbage left at curb is not property protected by the Fourth Amendment). Some would argue, *93I suppose, that testing of the urine is prohibited by some generalized privacy right “emanating” from the “penumbras” of the Constitution (a question that is not before us); but it is not even arguable that the testing of urine that has been lawfully obtained is a Fourth Amendment search. (I may add that, even if it were, the factors legitimizing the talcing of the sample, which I discuss below, would likewise legitimize the testing of it.)

It is rudimentary Fourth Amendment law that a search which has been consented to is not unreasonable. There is no contention in the present case that the urine samples were extracted forcibly. The only conceivable bases for saying that they were obtained without consent are the contentions (1) that the consent was coerced by the patients’ need for medical treatment, (2) that the consent was uninformed because the patients were not told that the tests would include testing for drugs, and (3) that the consent was uninformed because the patients were not told that the results of the tests would be provided to the police.1 (When the court below said that it was reserving the factual issue of consent, see 186 F. 8d 469, 476 (CA4 1999), it was referring at most to these three — and perhaps just to the last two.)

*94Under our established Fourth Amendment law, the last two contentions would not suffice, even without reference to the special-needs doctrine. The Court's analogizing of this case to Miranda v. Arizona, 384 U. S. 436 (1966), and its claim that “standards of knowing waiver" apply, ante, at 85, are flatly contradicted by our jurisprudence, which shows that using lawfully (but deceivingly) obtained material for purposes other than those represented, and giving that material or information derived from it to the police, is not unconstitutional. In Hoffa v. United States, 385 U. S. 293 (1966), “[t]he argument [was] that [the informant’s] failure to disclose his role as a government informant vitiated the consent that the petitioner gave” for the agent's access to evidence of criminal wrongdoing, id., at 300. We rejected that argument, because “the Fourth Amendment [does not protect] a wrongdoer’s misplaced belief that a person to whom he voluntarily confides his wrongdoing will not reveal it.” Id., at 302. Because the defendant had voluntarily provided access to the evidence, there was no reasonable expectation of privacy to invade. Abuse of trust is surely a sneaky and ungentlemanly thing, and perhaps there should be (as there are) laws against such conduct by the government. See, e. g., 50 U. S. C. §403-7 (1994 ed., Supp. IV) (prohibiting the “Intelligence Community['s]” use of journalists as agents). That, however, is immaterial for Fourth Amendment purposes, for “however strongly a defendant may trust an apparent colleague, his expectations in this respect are not protected by the Fourth Amendment when it turns out that the colleague is a government agent regularly communicating with the authorities.” United States v. White, 401U. S. 745, 749 (1971) (emphasis added). The Hoffa line of eases, I may note, does not distinguish between operations meant to catch a criminal in the act, and those meant only to gather evidence of prior wrongdoing. See, e.g., United States v. Miller, 425 U. S. 435, 440-443 (1976); cf. Illinois v. Perkins, 496 U. S. 292, 298 (1990) (relying on Hoffa in holding the *95 Miranda rule did not require suppression of an inmate confession given an agent posing as a fellow prisoner).

Until today, we have never held — or even suggested — that material which a person voluntarily entrusts to someone else cannot be given by that person to the police, and used for whatever evidence it may contain.2 Without so much as discussing the point, the Court today opens a hole in our Fourth Amendment jurisprudence, the size and shape of which is entirely indeterminate. Today’s holding would be remarkable enough if the confidential relationship violated by the police conduct were at least one protected by state law. It would be surprising to learn, for example, that in a State which recognizes a spousal evidentiary privilege the police cannot use evidence obtained from a cooperating husband or wife. But today’s holding goes even beyond that, since there does not exist any physician-patient privilege in South Carolina. See, e. g., Peagler v. Atlantic Coast R. R. Co., 232 S. C. 274, 101 S. E. 2d 821 (1958). Since the Court declines even to discuss the issue, it leaves law enforcement officials entirely in the dark as to when they can use incriminating evidence obtained from “trusted” sources.3 Presumably the *96lines will be drawn in the ease-by-ease development of a whole new branch of Fourth Amendment jurisprudence, taking yet another social judgment (which confidential relationships ought not be invaded by the police) out of democratic control, and confiding it to the uncontrolled judgment of this Court — uncontrolled because there is no common-law precedent to guide it. I would adhere to our established law, which says that information obtained through violation of a relationship of trust is obtained eonsensually, and is hence not a search.4

*97There remains to be considered the first possible basis for invalidating this search, which is that the patients were coerced to produce their urine samples by their necessitous circumstances, to wit, their need for medieal treatment of their pregnancy. If that was coercion, it was not coercion applied by the government — and if such nongovernmental coercion sufficed, the police would never be permitted to use the ballistic evidence obtained from treatment of a patient with a bullet wound. And the Fourth Amendment would invalidate those many state laws that require physicians to report gunshot wounds,5 evidence of spousal abuse,6 and (like the South Carolina law relevant here, see S. C. Code Ann. §20-7-510 (2000)) evidence of child abuse.7

*98II

I think it clear, therefore, that there is no basis for saying that obtaining of the urine sample was unconstitutional. The special-needs doctrine is thus quite irrelevant, since it operates only to validate searches and seizures that are otherwise unlawful. In the ensuing discussion, however, I shall assume (contrary to legal precedent) that the taking of the urine sample was (either because of the patients’ necessitous circumstances, or because of failure to disclose that the urine would be tested for drugs, or because of failure to disclose that the results of the test would be given to the police) coerced. Indeed, I shall even assume (contrary to common sense) that the testing of the urine constituted an uneon-sented search of the patients’ effects. On those assumptions, the special-needs doctrine would become relevant; and, properly applied, would validate what was done here.

The conclusion of the Court that the special-needs doctrine is inapplicable rests upon its contention that respondents “undert[ook] to obtain [drug] evidence from their patients” not for any medical purpose, but “for the specific purpose of incriminating those patients.” Ante, at 85 (emphasis in original). In other words, the purported medical rationale was merely a pretext; there was no special need. See Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 621, n. 5 (1989). This contention contradicts the District Court’s finding of fact that the goal of the testing policy “was not to arrest patients but to facilitate their treatment and protect both the mother and unborn child.” App. to Pet. for Cert. A-38.8 This finding is binding upon us unless clearly erro*99neous, see Fed. Rule Civ. Proe. 52(a). Not only do I find it supportable; I think any other finding would have to be overturned.

The cocaine tests started in April 1989, neither at police suggestion nor with police involvement. Expectant mothers who tested positive were referred by hospital staff for substance-abuse treatment, ante, at 70 (opinion of the Court) — an obvious health benefit to both mother and child. See App. 48 (testimony that a single use of cocaine can cause fetal damage). And, since “[ijnfants whose mothers abuse cocaine during pregnancy are born with a wide variety of physical and neurological abnormalities,” ante, at 89 (Kennedy, J., concurring in judgment), whieh require medical attention, see Brief in Opposition A76-A77, the tests were of additional medical benefit in predicting needed postnatal treatment for the child. Thus, in their origin — before the police were in any way involved — the tests had an immediate, not merely an "ultimate,” ante, at 82 (opinion of the Court), purpose of improving maternal and infant health. Several months after the testing had been initiated, a nurse discovered that local police were arresting pregnant users of eocaine for child abuse, the hospital’s general counsel wrote the county solicitor to ask "what, if anything, our Medical Center needs to do to assist you in this matter,” App. 499 (South Carolina law requires child abuse to be reported, see S. C. Code Ann. §20-7-510), the police suggested ways to avoid tainting evidence, and the hospital and police in conjunction used the testing program as a means of securing what the Court calls the "ultimate” health benefit of coercing drug-abusing mothers into drug treatment. See ante, at 70-73,82. Why would there be any reason to believe that, once *100this policy of using the drug tests for their "ultimate” health benefits had been adopted, use of them for their original, immediate, benefits somehow disappeared, and testing somehow became in its entirety nothing more than a “pretext” for obtaining grounds for arrest? On the face of it, this is incredible. The only evidence of the exclusively arrest-related purpose of the testing adduced by the Court is that the police-cooperation policy itself does not describe how to care for cocaine-exposed infants. See ante, at 73, 82. But of course it does not, since that policy, adopted months after the cocaine testing was initiated, had as its only health object the “ultimate” goal of inducing drug treatment through threat of arrest. Does the Court really believe (or even hope) that, once invalidation of the program challenged here has been decreed, drug testing will cease?

In sum, there can be no basis for the Court’s purported ability to “distinguislh.] this case from circumstances in which physicians or psychologists, in the course of ordinary medical procedures aimed at helping the patient herself, come across information that... is subject to reporting requirements,” ante, at 80-81, unless it is this: That the addition of a law-enforcement-related purpose to a legitimate medical purpose destroys applicability of the “special-needs” doctrine. But that is quite impossible, since the special-needs doctrine was developed, and is ordinarily employed, precisely to enable searches by law enforcement officials who, of course, ordinarily have a law enforcement objective. Thus, in Griffin v. Wisconsin, 483 U. S. 868 (1987), a probation officer received a tip from a detective that petitioner, a felon on probation, possessed a firearm. Accompanied by police, he conducted a warrantless search of petitioner’s home. The weapon was found and used as evidence in the probationer’s trial for unlawful possession of a firearm. See id., at 870-872. Affirming denial of a motion to suppress, we concluded that the “special need” of assuring compliance with terms of release *101justified a warrantless search of petitioner’s home. Notably, we observed that a probation officer is not

“the police officer who normally conducts searches against the ordinary citizen. He is an employee of the State Department of Health and Social Services who, while assuredly charged with protecting the public interest, is also supposed to have in mind the welfare of the probationer .... In such a setting, we think it reasonable to dispense with the warrant requirement.” Id., at 876-877.

Like the probation officer, the doctors here do not “ordinarily condue[t] searches against the ordinary citizen,” and they are “supposed to have in mind the welfare of the [mother and child].” That they have in mind in addition the provision of evidence to the police should make no difference. The Court suggests that if police involvement in this case was in some way incidental and after-the-fact, that would make a difference in the outcome. See ante, at 80-84. But in Griffin, even more than here, police were involved in the search from the very beginning; indeed, the initial tip about the gun came from a detective. Under the factors relied upon by the Court, the use of evidence approved in Griffin would have been permitted only if the parole officer had been untrained in ehain-of-eustody procedures, had not known of the possibility a gun was present, and had been unaccompanied by police when he simply happened upon the weapon. Why any or all of these is constitutionally significant is baffling.

Petitioners seek to distinguish Griffin by observing that probationers enjoy a lesser expectation of privacy than does the general public. That is irrelevant to the point I make here, which is that the presence of a law enforcement purpose does not render the special-needs doctrine inapplicable. In any event, I doubt whether Griffin’s reasonable expectation of privacy in his home was any less than petitioners’ reasonable expectation of privacy in their urine taken, *102or in the urine tests performed, in a hospital — especially in a State such as South Carolina, which recognizes no physician-patient testimonial privilege and requires the physician’s duty of confidentiality to yield to public policy, see McCormick v. England, 328 S. C. 627, 633, 640-642, 494 S. E. 2d 431, 434, 438-439 (App. 1997); and which requires medical conditions that indicate a violation of the law to be reported to authorities, see, e.g., S. C. Code Ann. §20-7-510 (2000) (child abuse). Cf. Whalen v. Roe, 429 U. S. 589, 597-598 (1977) (privacy interest does not forbid government to require hospitals to provide, for law enforcement purposes, names of patients receiving prescriptions of frequently abused drugs).

The concurrence makes essentially the same basic error as the Court, though it puts the point somewhat differently: “The special needs cases we have decided,” it says, “do not sustain the active use of law enforcement... as an integral part of a program which seeks to achieve legitimate, civil objectives.” Ante, at 88. Griffin shows that is not true. Indeed, Griffin shows that there is not even any truth in the more limited proposition that our cases do not support application of the special-needs exception where the “legitimate, civil objectives” are sought only through the use of law enforcement means. (Surely the parole officer in Griffin was using threat of reincareeration to assure compliance with parole.) But even if this latter proposition were true, it would invalidate what occurred here only if the drug testing sought exclusively the “ultimate” health benefits achieved by coercing the mothers into drug treatment through threat of prosecution. But in fact the drug testing sought, independently of law enforcement involvement, the “immediate” health benefits of identifying drug-impaired mother and child for necessary medical treatment. The concurrence concedes that if the testing is conducted for medical reasons, the fact that “prosecuting authorities then adopt legitimate procedures to discover this information and prosecution follows *103... ought not to invalidate the testing.” Ante, at 90 (emphasis added). But here the police involvement in each case did take place after the testing was conducted for independent reasons. Surely the concurrence cannot mean that no police-suggested procedures (such as preserving the chain of custody of the urine sample) can be applied until after the testing; or that the police-suggested procedures must have been designed after the testing. The facts in Griffin (and common sense) show that this cannot be so. It seems to me that the only real distinction between what the concurrence must reasonably be thought to be approving, and what we have here, is that here the police took the lesser step of initially threatening prosecution rather than bringing it.

* * *

As I indicated at the outset, it is not the function of this Court — at least not in Fourth Amendment cases — to weigh petitioners’ privacy interest against the State’s interest in meeting the crisis of “crack babies” that developed in the late 1980’s. I cannot refrain from observing, however, that the outcome of a wise weighing of those interests is by no means clear. The initial goal of the doctors and nurses who conducted cocaine testing in this case was to refer pregnant drug addicts to treatment centers, and to prepare for necessary treatment of their possibly affected children. When the doctors and nurses agreed to the program providing test results to the police, they did so because (in addition to the fact that child abuse was required by law to be reported) they wanted to use the sanction of arrest as a strong incentive for their addicted patients to undertake drug-addiction treatment. . And the police themselves used it for that benign purpose, as is shown by the fact that only 30 of 253 women testing positive for cocaine were ever arrested, and only 2 of those prosecuted. See App. 1125-1126. It would not be unreasonable to conclude that today’s judgment, authorizing the assessment of damages against the county *104solicitor and individual doctors and nurses who participated in the program, proves once again that no good deed goes unpunished.

But as far as the Fourth Amendment is concerned: There was no unconsented search in this case. And if there was, it would have been validated by the special-needs doctrine. For these reasons, I respectfully dissent.

*870Justice Scalia

delivered the opinion of the Court.

Petitioner Joseph Griffin, who was on probation, had his home searched by probation officers acting without a warrant. The officers found a gun that later served as the basis of Griffin’s conviction of a state-law weapons offense. We granted certiorari, 479 U. S. 1005 (1986), to consider whether this search violated the Fourth Amendment.

I

On September 4, 1980, Griffin, who had previously been convicted of a felony, was convicted in Wisconsin state court of resisting arrest, disorderly conduct, and obstructing an officer. He was placed on probation.

Wisconsin law puts probationers in the legal custody of the State Department of Health and Social Services and renders them “subject . . . to . . . conditions set by the court and rules and regulations established by the department.” Wis. Stat. § 973.10(1) (1985-1986). One of the Department’s regulations permits any probation officer to search a proba*871tioner’s home without a warrant as long as his supervisor approves and as long as there are “reasonable grounds” to believe the presence of contraband — including any item that the probationer cannot possess under the probation conditions. Wis. Admin. Code HSS §§ 328.21(4), 328.16(1) (1981).1 The rule provides that an officer should consider a variety of factors in determining whether “reasonable grounds” exist, among which are information provided by an informant, the reliability and specificity of that information, the reliability of the informant (including whether the informant has any incentive to supply inaccurate information), the officer’s own experience with the probationer, and the “need to verify compliance with rules of supervision and state and federal law.” HSS §328.21(7). Another regulation makes it a violation of the terms of probation to refuse to consent to a home search. HSS § 328.04(3)(k). And still another forbids a probationer to possess a firearm without advance approval from a probation officer. HSS § 328.04(3)(j).

On April 5, 1983, while Griffin was still on probation, Michael Lew, the supervisor of Griffin’s probation officer, received information from a detective on the Beloit Police Department that there were or might be guns in Griffin’s apartment. Unable to secure the assistance of Griffin’s own probation officer, Lew, accompanied by another probation officer and three plainclothes policemen, went to the apartment. When Griffin answered the door, Lew told him who they were and informed him that they were going to search his home. During the subsequent search — carried out entirely by the probation officers under the authority of Wisconsin’s probation regulation — they found a handgun.

*872Griffin was charged with possession of a firearm by a convicted felon, which is itself a felony. Wis. Stat. §941.29(2) (1985-1986). He moved to suppress the evidence seized during the search. The trial court denied the motion, concluding that no warrant was necessary and that the search was reasonable. A jury convicted Griffin of the firearms violation, and he was sentenced to two years’ imprisonment. The conviction was affirmed by the Wisconsin Court of Appeals, 126 Wis. 2d 183, 376 N. W. 2d 62 (1985).

On further appeal, the Wisconsin Supreme Court also affirmed. It found denial of the suppression motion proper because probation diminishes a probationer’s reasonable expectation of privacy — so that a probation officer may, consistent with the Fourth Amendment, search a probationer’s home without a warrant, and with only “reasonable grounds” (not probable cause) to believe that contraband is present. It held that the “reasonable grounds” standard of Wisconsin’s search regulation satisfied this “reasonable grounds” standard of the Federal Constitution, and that the detective’s tip established “reasonable grounds” within the meaning of the regulation, since it came from someone who had no reason to supply inaccurate information, specifically identified Griffin, and suggested a need to verify Griffin’s compliance with state law. 131 Wis. 2d 41, 52-64, 388 N. W. 2d 535, 539-544 (1986).

II

We think the Wisconsin Supreme Court correctly concluded that this warrantless search did not violate the Fourth Amendment. To reach that result, however, we find it unnecessary to embrace a new principle of law, as the Wisconsin court evidently did, that any search of a probationer’s home by a probation officer satisfies the Fourth Amendment as long as the information possessed by the officer satisfies a federal “reasonable grounds” standard. As his sentence for the commission of a crime, Griffin was committed to the legal custody of the Wisconsin State Department of Health and *873Social Services, and thereby made subject to that Department’s rules and regulations. The search of Griffin’s home satisfied the demands of the Fourth Amendment because it was carried out pursuant to a regulation that itself satisfies the Fourth Amendment’s reasonableness requirement under well-established principles.

A

A probationer’s home, like anyone else’s, is protected by the Fourth Amendment’s requirement that searches be “reasonable.” Although we usually require that a search be undertaken only pursuant to a warrant (and thus supported by probable cause, as the Constitution says warrants must be), see, e. g., Payton v. New York, 445 U. S. 573, 586 (1980), we have permitted exceptions when “special needs, beyond the normal need for law enforcement, make the warrant and probable-cause requirement impracticable.” New Jersey v. T. L. O., 469 U. S. 325, 351 (1985) (Blackmun, J., concurring in judgment). Thus, we have held that government employers and supervisors may conduct warrantless, work-related searches of employees’ desks and offices without probable cause, O’Connor v. Ortega, 480 U. S. 709 (1987), and that school officials may conduct warrantless searches of some student property, also without probable cause, New Jersey v. T. L. O., swpra. We have also held, for similar reasons, that in certain circumstances government investigators conducting searches pursuant to a regulatory scheme need not adhere to the usual warrant or probable-cause requirements as long as their searches meet “reasonable legislative or administrative standards.” Camara v. Municipal Court, 387 U. S. 523, 538 (1967). See New York v. Burger, 482 U. S. 691, 702-703 (1987); Donovan v. Dewey, 452 U. S. 594, 602 (1981); United States v. Biswell, 406 XJ. S. 311, 316 (1972).

A State’s operation of a probation system, like its operation of a school, government office or prison, or its supervision of a regulated industry, likewise presents “special *874needs” beyond normal law enforcement that may justify departures from the usual warrant and probable-cause requirements. Probation, like incarceration, is “a form of criminal sanction imposed by a court upon an offender after verdict, finding, or plea of guilty.” G. Killinger, H. Kerper, & P. Cromwell, Probation and Parole in the Criminal Justice System 14 (1976); see also 18 U. S. C. § 3651 (1982 ed. and Supp. III) (probation imposed instead of imprisonment); Wis. Stat. § 973.09 (1985-1986) (same).2 Probation is simply one point (or, more accurately, one set of points) on a continuum of possible punishments ranging from solitary confinement in a maximum-security facility to a few hours of mandatory community service. A number of different options lie between those extremes, including confinement in a medium- or minimum-security facility, work-release programs, “halfway houses,” and probation — which can itself be more or less confining depending upon the number and severity of restrictions imposed. See, e. g., 18 U. S. C. §3563 (1982 ed., Supp. III) (effective Nov. 1, 1987) (probation conditions authorized in federal system include requiring probationers to avoid commission of other crimes; to pursue employment; to avoid certain occupations, places, and people; to spend evenings or weekends in prison; and to avoid narcotics or excessive use of alcohol). To a greater or lesser degree, it is always true of probationers (as we have said it to be true of parolees) that they do not enjoy “the absolute liberty to which every citizen is entitled, but only . . . conditional liberty properly dependent on observance of special [probation] restrictions.” Morrissey v. Brewer, 408 U. S. 471, 480 (1972).

*875These restrictions are meant to assure that the probation serves as a period of genuine rehabilitation and that the community is not harmed by the probationer’s being at large. See State v. Tarrell, 74 Wis. 2d 647, 652-653, 247 N. W. 2d 696, 700 (1976). These same goals require and justify the exercise of supervision to assure that the restrictions are in fact observed. Recent research suggests that more intensive supervision can reduce recidivism, see Petersilia, Probation and Felony Offenders, 49 Fed. Probation 9 (June 1985), and the importance of supervision has grown as probation has become an increasingly common sentence for those convicted of serious crimes, see id., at 4. Supervision, then, is a “special need” of the State permitting a degree of impingement upon privacy that would not be constitutional if applied to the public at large. That permissible degree is not unlimited, however, so we next turn to whether it has been exceeded here.

B

In determining whether the “special needs” of its probation system justify Wisconsin’s search regulation, we must take that regulation as it has been interpreted by state corrections officials and state courts. As already noted, the Wisconsin Supreme Court — the ultimate authority on issues of Wisconsin law — has held that a tip from a police detective that Griffin “had” or “may have had” an illegal weapon at his home constituted the requisite “reasonable grounds.” See 131 Wis. 2d, at 64, 388 N. W. 2d, at 544. Whether or not we would choose to interpret a similarly worded federal regulation in that fashion, we are bound by the state court’s interpretation, which is relevant to our constitutional analysis only insofar as it fixes the meaning of the regulation.3 We *876think it clear that the special needs of Wisconsin’s probation system make the warrant requirement impracticable and justify replacement of the standard of probable cause by “reasonable grounds,” as defined by the Wisconsin Supreme Court.

A warrant requirement would interfere to an appreciable degree with the probation system, setting up a magistrate rather than the probation officer as the judge of how close a supervision the probationer requires. Moreover, the delay inherent in obtaining a warrant would make it more difficult for probation officials to respond quickly to evidence of misconduct, see New Jersey v. T. L. O., 469 U. S., at 340, and would reduce the deterrent effect that the possibility of expeditious searches would otherwise create, see New York v. Burger, 482 U. S., at 710; United States v. Biswell, 406 U. S., at 316. By way of analogy, one might contemplate how parental custodial authority would be impaired by requiring judicial approval for search of a minor child’s room. And on the other side of the equation — the effect of dispensing with a warrant upon the probationer: Although a probation officer is not an impartial magistrate, neither is he the police officer who normally conducts searches against the ordinary citizen. He is an employee of the State Department of Health and Social Services who, while assuredly charged with protecting the public interest, is also supposed to have in mind the welfare of the probationer (who in the regulations is called a “client,” HSS § 328.03(5)). The applicable regulations require him, for example, to “[p]rovid[e] individualized counseling designed to foster growth and development of the client as necessary,” HSS § 328.04(2)(i), and “[m]onito[r] the *877client’s progress where services are provided by another agency and evaluate] the need for continuation of the services,” HSS §328.04(2)(o). In such a setting, we think it reasonable to dispense with the warrant requirement.

Justice Blackmun’s dissent would retain a judicial warrant requirement, though agreeing with our subsequent conclusion that reasonableness of the search does not require probable cause. This, however, is a combination that neither the text of the Constitution nor any of our prior decisions permits. While it is possible to say that Fourth Amendment reasonableness demands probable cause without a judicial warrant, the reverse runs up against the constitutional provision that “no Warrants shall issue, but upon probable cause.” Arndt. 4. The Constitution prescribes, in other words, that where the matter is of such a nature as to require a judicial warrant, it is also of such a nature as to require probable cause. Although we have arguably come to permit an exception to that prescription for administrative search warrants,4 which may but do not necessarily have to be issued by courts,8 we have never done so for constitutionally mandated judicial *878warrants. There it remains true that “[i]f a search warrant be constitutionally required, the requirement cannot be flexibly interpreted to dispense with the rigorous constitutional restrictions for its issue.” Frank v. Maryland, 359 U. S. 360, 373 (1959). Justice Blackmun neither gives a justification for departure from that principle nor considers its implications for the body of Fourth Amendment law.

We think that the probation regime would also be unduly disrupted by a requirement of probable cause. To take the facts of the present case, it is most unlikely that the unauthenticated tip of a police officer — bearing, as far as the record shows, no indication whether its basis was firsthand knowledge or, if not, whether the firsthand source was reliable, and merely stating that Griffin “had or might have” guns in his residence, not that he certainly had them — would meet the ordinary requirement of probable cause. But this is different from the ordinary case in two related respects: First, even more than the requirement of a warrant, a probable-cause requirement would reduce the deterrent effect of the supervisory arrangement. The probationer would be assured that so long as his illegal (and perhaps socially dangerous) activities were sufficiently concealed as to give rise to no more than reasonable suspicion, they would go undetected and uncorrected. The second difference is well reflected in the regulation specifying what is to be considered “[i]n deciding whether there are reasonable grounds to believe ... a client’s living quarters or property contain contraband,” HSS §328.21(7). The factors include not only the usual elements that a police officer or magistrate would consider, such as the detail and consistency of the information suggesting the presence of contraband and the reliability and motivation to dissemble of the informant, HSS §§328.21(7) (c), (d), but also “[ijnformation provided by the client which is relevant to whether the client possesses contraband,” and “[t]he experience of a staff member with that client or in a *879similar circumstance.” HSS §§ 328.21(7)(f), (g). As was true, then, in O’Connor v. Ortega, 480 U. S. 709 (1987), and New Jersey v. T. L. O., 469 U. S. 325 (1985), we deal with a situation in which there is an ongoing supervisory relationship —and one that is not, or at least not entirely, adversarial— between the object of the search and the decisionmaker.6

In such circumstances it is both unrealistic and destructive of the whole object of the continuing probation relationship to insist upon the same degree of demonstrable reliability of particular items of supporting data, and upon the same degree of certainty of violation, as is required in other contexts. In some cases — especially those involving drugs or illegal weapons — the probation agency must be able to act based upon a lesser degree of certainty than the Fourth Amendment would otherwise require in order to intervene before a probationer does damage to himself or society. The agency, moreover, must be able to proceed on the basis of its entire experience with the probationer, and to assess probabilities in the light of its knowledge of his life, character, and circumstances.

To allow adequate play for such factors, we think it reasonable to permit information provided by a police officer,7 *880whether or not on the basis of firsthand knowledge, to support a probationer search. The same conclusion is suggested by the fact that the police máy be unwilling to disclose their confidential sources to probation personnel. For the same reason, and also because it is the very assumption of the institution of probation that the probationer is in need of rehabilitation and is more likely than the ordinary citizen to violate the law, we think it enough if the information provided indicates, as it did here, only the likelihood (“had or might have guns”) of facts justifying the search.8

The search of Griffin’s residence was “reasonable” within the meaning of the Fourth Amendment because it was conducted pursuant to a valid regulation governing probationers. This conclusion makes it unnecessary to consider whether, as the court below held and the State urges, any search of a probationer’s home by a probation officer is lawful when there are “reasonable grounds” to believe contraband is present. For the foregoing reasons, the judgment of the Wisconsin Supreme Court is

Affirmed.

*881Justice Blackmun,

with whom

Justice Marshall joins and, as to Parts I-B and I-C, Justice Brennan joins and, as to Part I-C, Justice Stevens joins, dissenting.

In ruling that the home of a probationer may be searched by a probation officer without a warrant, the Court today takes another step that diminishes the protection given by the Fourth Amendment to the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” In my view, petitioner’s probationary status provides no reason to abandon the warrant requirement. The probation system’s special law enforcement needs may justify a search by a probation officer on the basis of “reasonable suspicion,” but even that standard was not met in this case.

I

The need for supervision in probation presents one of the “exceptional circumstances in which special needs, beyond the normal need for law enforcement,” New Jersey v. T. L. O., 469 U. S. 325, 351 (1985) (opinion concurring in judgment), justify an application of the Court’s balancing test and an examination of the practicality of the warrant and probable-cause requirements. The Court, however, fails to recognize that this is a threshold determination of special law enforcement needs. The warrant and probable-cause requirements provide the normal standard for “reasonable” searches. “[0]nly when the practical realities of a particular situation suggest that a government official cannot obtain a warrant based upon probable cause without sacrificing the ultimate goals to which a search would contribute, does the Court turn to a ‘balancing’ test to formulate a standard of reasonableness for this context.” O’Connor v. Ortega, 480 U. S. 709, 741 (1987) (dissenting opinion). The presence of special law enforcement needs justifies resort to the balancing test, but it does not preordain the necessity of recognizing exceptions to the warrant and probable-cause requirements.

*882My application of the balancing test leads me to conclude that special law enforcement needs justify a search by a probation agent of the home of a probationer on the basis of a reduced level of suspicion. The acknowledged need for supervision, however, does not also justify an exception to the warrant requirement, and I would retain this means of protecting a probationer’s privacy.1 Moreover, the necessity for the neutral check provided by the warrant requirement is demonstrated by this case, in which the search was conducted on the basis of information that did not begin to approach the level of “reasonable grounds.”

A

The probation officer is not dealing with an average citizen, but with a person who has been convicted of a crime.2 This presence of an offender in the community creates the need for special supervision. I therefore agree that a probation agent must have latitude in observing a probationer if the agent is to carry out his supervisory responsibilities effectively. Re*883cidivism among probationers is a major problem, and supervision is one means of combating that threat. See ante, at 875. Supervision also provides a crucial means of advancing rehabilitation by allowing a probation agent to intervene at the first sign of trouble.

One important aspect of supervision is the monitoring of a probationer’s compliance with the conditions of his probation. In order to ensure compliance with those conditions, a probation agent may need to search a probationer’s home to check for violations. While extensive inquiry may be required to gather the information necessary to establish probable cause that a violation has occurred, a “reasonable grounds” standard allows a probation agent to avoid this delay and to intervene at an earlier stage of suspicion. This standard is thus consistent with the level of supervision necessary to protect the public and to aid rehabilitation. At the same time, if properly applied, the standard of reasonable suspicion will protect a probationer from unwarranted intrusions into his privacy.

B

I do not think, however, that special law enforcement needs justify a modification of the protection afforded a probationer’s privacy by the warrant requirement. The search in this case was conducted in petitioner’s home, the place that traditionally has been regarded as the center of a person’s private life, the bastion in which one has a legitimate expectation of privacy protected by the Fourth Amendment. See Silverman v. United States, 365 U. S. 505, 511 (1961) (“At the very core [of the Fourth Amendment] stands the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion”). The Court consistently has held that warrantless searches and seizures in a home violate the Fourth Amendment absent consent or exigent circumstances. See, e. g., United States v. Karo, 468 U. S. 705, 714-715 (1984); Steagald v. United States, 451 U. S. 204 (1981) (arrest warrant inadequate for *884search of home of a third party); Payton v. New York, 445 U. S. 573 (1980) (warrantless arrest of suspect in his home unconstitutional).

“It is axiomatic that the ‘physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed.’ United States v. United States District Court, 407 U. S. 297, 313 (1972). And a principal protection against unnecessary intrusions into private dwellings is the warrant requirement imposed by the Fourth Amendment on agents of the government who seek to enter the home for purposes of search or arrest. It is not surprising, therefore, that the Court has recognized, as ‘a “basic principle of Fourth Amendment law[,]” that searches and seizures inside a home without a warrant are presumptively unreasonable.’ Payton v. New York, 445 U. S., at 586.” Welsh v. Wisconsin, 466 U. S. 740, 748-749 (1984) (footnote and citation omitted).

The administrative-inspection cases are inapposite to a search of a home. Each of the cases that this Court has found to fall within the exception to the administrative-warrant requirement has concerned the lesser expectation of privacy attached to a “closely regulated” business. See, e. g., New York v. Burger, 482 U. S. 691 (1987) (vehicle dismantlers); Donovan v. Dewey, 452 U. S. 594 (1981) (mines); United States v. Biswell, 406 U. S. 311 (1972) (gun dealers). The reasoning that may justify an administrative inspection without a warrant in the case of a business enterprise simply does not extend to the invasion of the special privacy the Court has recognized for the home.

A probationer usually lives at home, and often, as in this case, with a family. He retains a legitimate privacy interest in the home that must be respected to the degree that it is not incompatible with substantial governmental needs. The Court in New Jersey v. T. L. O. acknowledged that the Fourth Amendment issue needs to be resolved in such a way *885as to “ensure that the [privacy] interests of students will be invaded no more than is necessary to achieve the legitimate end of preserving order in the schools.” 469 U. S., at 343. The privacy interests of probationers should be protected by a similar standard, and invaded no more than is necessary to satisfy probation’s dual goals of protecting the public safety and encouraging the rehabilitation of the probationer.

The search in this case was not the result of an ordinary home visit by petitioner’s probation agent for which no warrant is required. Cf. Wyman v. James, 400 U. S. 309 (1971). It was a search pursuant to a tip, ostensibly from the police, for the purpose of uncovering evidence of a criminal violation. There is nothing about the status of probation that justifies a special exception to the warrant requirement under these circumstances. If in a particular case there is a compelling need to search the home of a probationer without delay, then it is possible for a search to be conducted immediately under the established exception for exigent circumstances. There is no need to create a separate warrant exception for probationers. The existing exception provides a probation agent with all the flexibility the agent needs.

The circumstances of this case illustrate the fact that the warrant requirement does not create any special impediment to the achievement of the goals of probation. The probation supervisor, Michael T. Lew, waited “[t]wo or three hours” after receiving the telephone tip before he proceeded to petitioner’s home to conduct the search. App. 16. He testified that he was waiting for the return of petitioner’s official agent who was attending a legal proceeding, and that eventually he requested another probation agent to initiate the search. Id., at 16, 51. Mr. Lew thus had plenty of time to obtain a search warrant. If the police themselves had investigated the report of a gun at petitioner’s residence, they would have been required to obtain a warrant. There simply was no compelling reason to abandon the safeguards provided by neutral review.

*886The Court appears to hold the curious assumption that the probationer will benefit by dispensing with the warrant requirement. It notes that a probation officer does not normally conduct searches, as does a police officer, and, moreover, the officer is “supposed to have in mind the welfare of the probationer.” Ante, at 876. The implication is that a probation agent will be less likely to initiate an inappropriate search than a law-enforcement officer, and is thus less in need of neutral review. Even if there were data to support this notion, a reduced need for review does not justify a complete removal of the warrant requirement. Furthermore, the benefit that a probationer is supposed to gain from probation is rehabilitation. I fail to see how the role of the probation agent in “ 'fosterling] growth and development of the client,’” ibid., quoting Wis. Admin. Code HSS §328.04 (2)(i) (1981), is enhanced the slightest bit by the ability to conduct a search without the checks provided by prior neutral review. If anything, the power to decide to search will prove a barrier to establishing any degree of trust between agent and “client.”

The Court also justifies the exception to the warrant requirement that it would find in the Wisconsin regulations by stressing the need to have a probation agent, rather than a judge, decide how closely supervised a particular probationer should be. See ante, at 876. This argument mistakes the nature of the search at issue. The probation agent retains discretion over the terms of a probationer’s supervision — the warrant requirement introduces a judge or a magistrate into the decision only when a full-blown search for evidence of a criminal violation is at stake. The Court’s justification for the conclusion that the warrant requirement would interfere with the probation system by way of an analogy to the authority possessed by parents over their children is completely unfounded. The difference between the two situations is too obvious to belabor. Unlike the private nature of a parent’s interaction with his or her child, the probation system is a *887governmental operation, with explicit standards. Experience has shown that a neutral judge can best determine if those standards are met and a search is justified. This case provides an excellent illustration of the need for neutral review of a probation officer’s decision to conduct a search, for it is obvious that the search was not justified even by a reduced standard of reasonable suspicion.

C

The Court concludes that the search of petitioner’s home satisfied the requirements of the Fourth Amendment “because it was carried out pursuant to a regulation that itself satisfies the Fourth Amendment’s reasonableness requirement under well-established principles.” Ante, at 873. In the Court’s view, it seems that only the single regulation requiring “reasonable grounds” for a search is relevant to its decision. Ante, at 880, n. 8. When faced with the patent failure of the probation agents to comply with the Wisconsin regulations, the Court concludes that it “is irrelevant to the case before us” that the probation agents “may have violated Wisconsin state regulations.” Ibid. All of these other regulations, which happen to define the steps necessary to ensure that reasonable grounds are present, can be ignored. This conclusion that the existence of a facial requirement for “reasonable grounds” automatically satisfies the constitutional protection that a search be reasonable can only be termed tautological. The content of a standard is found in its application and, in this case, I cannot discern the application of any standard whatsoever.

The suspicion in this case was based on an unverified tip from an unknown source. With or without the Wisconsin regulation, such information cannot constitutionally justify a search. Mr. Lew testified that he could not recall which police officer called him with the information about the gun, although he thought it “probably” was Officer Pittner. App. 16. Officer Pittner, however, did not remember making any *888such telephone call. Id., at 39. From all that the record reveals, the call could have been placed by anyone. It is even plausible that the information did not come from the police at all, but from someone impersonating an officer.

Even assuming that a police officer spoke to Mr. Lew, there was little to demonstrate the reliability of the information he received from that unknown officer. The record does not reveal even the precise content of the tip. The unknown officer actually may have reported that petitioner “had” contraband in his possession, id., at 51, or he merely may have suggested that petitioner “may have had guns in his apartment.” Id., at 14. Mr. Lew testified to both at different stages of the proceedings. Nor do we know anything about the ultimate source of the information. The unknown officer’s belief may have been founded on a hunch, a rumor, or an informant’s tip. Without knowing more about the basis of the tip, it is impossible to form a conclusion, let alone a reasonable conclusion, that there were “reasonable grounds” to justify a search.

Mr. Lew failed completely to make the most rudimentary effort to confirm the information he had received or to evaluate whether reasonable suspicion justified a search. Conspicuously absent was any attempt to comply with the Wisconsin regulations that governed the content of the “reasonable grounds” standard. Wis. Admin. Code HSS § 328.21(7) (1981).3 No observations of a staff member could *889have been considered, as required by subsection (7)(a), for Mr. Lew did not consult the agent who had personal knowledge of petitioner’s case. When information was provided by an informant, subsections (7)(c) and (d) required evaluation of the reliability of the information relied upon and the reliability of the informant. Mr. Lew proceeded in violation of these basic requirements. Subsection (7)(f) referred to “information provided by the client” and the explanatory notes stated that “the client should be talked to before the search. Sometimes, this will elicit information helpful in determining whether a search should be made.” § 328.21 App., p. 250. This requirement, too, was ignored. Nor do any of the other considerations support a finding of reasonable grounds to conduct the search. There is no indication that there had been prior seizures of contraband from petitioner, or that his case presented any special need to verify compliance with the law. See §§ 328.21(7)(h) and (i).

The majority acknowledges that it is “most unlikely” that the suspicion in this case would have met the normal “probable cause” standard. Ante, at 878. It concludes, however, that this is not an “ordinary” case because of the need for supervision and the continuing relationship between the probationer and the probation agency. Ibid. In view of this con-*890timing relationship, the regulations mandated consideration of factors that go beyond those normally considered in determining probable cause to include information provided by the probationer and the experience of the staff member with the probationer. But unless the agency adheres to the regulations, it is sophistic to rely on them as a justification for conducting a search on a lesser degree of suspicion. Mr. Lew drew on no special knowledge of petitioner in deciding to search his house. He had no contact with the agent familiar with petitioner’s case before commencing the search. Nor, as discussed above, was there the slightest attempt to obtain information from petitioner. In this case, the continuing relationship between petitioner and the agency did not supply support for any suspicion, reasonable or otherwise, that would justify a search of petitioner’s home.

II

There are many probationers in this country, and they have committed crimes that range widely in seriousness. The Court has determined that all of them may be subjected to such searches in the absence of a warrant. Moreover, in authorizing these searches on the basis of a reduced level of suspicion, the Court overlooks the feeble justification for the search in this case.

I respectfully dissent.

Justice Stevens,

with whom

Justice Marshall joins, dissenting.

Mere speculation by a police officer that a probationer “may have had” contraband in his possession is not a constitutionally sufficient basis for a warrantless, nonconsensual search of a private home. I simply do not understand how five Members of this Court can reach a contrary conclusion. Accordingly, I respectfully dissent.