Mr. Justice Stewart

delivered the opinion of the Court.

It is well settled under the Fourth and Fourteenth Amendments that a search conducted without a warrant issued upon probable cause is “per se unreasonable . . . subject only to a few specifically established and well-delineated exceptions.” Katz v. United States, 389 U. S. 347, 357; Coolidge v. New Hampshire, 403 U. S. 443, 454-455; Chambers v. Maroney, 399 U. S. 42, 51. It is equally well settled that one of the specifically established exceptions to the requirements of both a warrant and probable cause is a search that is conducted pursuant to consent. Davis v. United States, 328 U. S. 582, 593-594; Zap v. United States, 328 U. S. 624, 630. The constitutional question in the present case concerns the definition of “consent” in this Fourth and Fourteenth Amendment context.

I

The respondent was brought to trial in a California court upon a charge of possessing a check with intent to defraud.1 He moved to suppress the introduction of certain material as evidence against him on the ground that the material had been acquired through an unconstitutional search and seizure. In response to the motion, the trial judge conducted an evidentiary hearing *220where it was established that the material in question had been acquired by the State under the following circumstances:

While on routine patrol in Sunnyvale, California, at approximately 2:40 in the morning, Police Officer James Rand stopped an automobile when he observed that one headlight and its license plate light were burned out. Six men were in the vehicle. Joe Alcala and the respondent, Robert Bustamonte, were in the front seat with Joe Gonzales, the driver. Three older men were seated in the rear. When, in response to the policeman's question, Gonzales could not produce a driver’s license, Officer Rand asked if any of thé other five had any evidence of identification. Only Alcala produced a license, and he explained that the car was his brother’s. After the six occupants had stepped out of the car at the officer’s request and after two additional policemen had arrived, Officer Rand asked Alcala if he could search the car. Alcala replied, “Sure, go ahead.” Prior to the search no one was threatened with arrest and, according to Officer Rand’s uncontradicted testimony, it “was all very congenial at this time.” Gonzales testified that Alcala actually helped in the search of the car, by opening the trunk and glove compartment. In Gonzales’ words: “[T]he police officer asked Joe [Alcala], he goes, 'Does the trunk open?’ And Joe said, 'Yes.’ He went to the car and got the keys and opened up the trunk.” Wadded up under the left rear seat, the police officers found three checks that had previously been stolen from a car wash.

The trial judge denied the motion to suppress, and the checks in question were admitted in evidence ar Bustamonte’s trial. On the basis of this and other evidence he was convicted, and the California Court of Appeal for the First Appellate District affirmed the convic*221tion. 270 Cal. App. 2d 648, 76 Cal. Rptr. 17. In agreeing that the search and seizure were constitutionally valid, the appellate court applied the standard earlier formulated by the Supreme Court of California in an opinion by then Justice Traynor: “Whether in a particular case an apparent consent was in fact voluntarily given or was in submission to an express or implied assertion of authority, is a question of fact to be determined in the light of all the circumstances.” People v. Michael, 45 Cal. 2d 751, 753, 290 P. 2d 852, 854. The appellate court-found that “[i]n the instant case the prosecution met the necessary burden of showing consent . . . since there were clearly circumstances from which the trial court could ascertain that consent had been freely given without coercion or submission to authority. Not only officer Rand, but Gonzales, the driver of the automobile, testified that Alcala’s assent to the search of his brother’s automobile was freely, even casually given. At the time of the request to search the automobile the atmosphere, according to Rand, was ‘congenial’ and there had been no discussion of any crime. As noted, Gonzales said Alcala even attempted to aid in the search.” 270 Cal. App. 2d, at 652, 76 Cal. Rptr., at 20. The California Supreme Court denied review.2

Thereafter, the respondent sought a writ of habeas corpus in a federal district court. It was denied.3 On appeal, the Court of Appeals for the Ninth Circuit, relying on its prior decisions in Ciprés v. United States, 343 F. 2d 95, and Schoepflin v. United States, 391 F. 2d 390, set aside the District Court’s order. 448 F. 2d 699. The appellate court reasoned that a consent was a waiver of a person’s Fourth and Fourteenth Amendment rights, and that the State was under an obligation to demon*222strate, not only that the consent had been uncoerced, but that it had been given with an understanding that it could be freely and effectively withheld. Consent could not be found, the court held, solely from the absence of coercion and a verbal expression of assent. Since the District Court had not determined that Alcala had known that his consent could have been withheld and that he could have refused to have his vehicle searched, the Court of Appeals vacated the order denying the writ and remanded the case for further proceedings. We granted certiorari to determine whether the Fourth and Fourteenth Amendments require the showing thought necessary by the Court of Appeals. 405 U. S. 953.

II

It is important to make it clear at the outset what is not involved in this case. The respondent concedes that a search conducted pursuant to a valid consent is constitutionally permissible. In Katz v. United States, 389 U. S., at 358, and more recently in Vale v. Louisiana, 399 U. S. 30, 35, we recognized that a search authorized by consent is wholly valid. See also Davis v. United States, 328 U. S., at 593-594; Zap v. United States, 328 U. S., at 630.4 And similarly the State concedes that “[w]hen a prosecutor seeks to rely upon consent to justify the lawfulness of a search, he has the burden of proving that the consent was, in fact, freely and voluntarily given1.” Bumper v. North Carolina, 391 U. S. 543, 548. See also Johnson v. United States, 333 U. S. 10; Amos v. United States, 255 U. S. 313.

*223The precise question in this case, then, is what must the prosecution prove to demonstrate that a consent was “voluntarily” given. And upon that question there is a square conflict of views between the state and federal courts that have reviewed the search involved in the case before us. The Court of Appeals for the Ninth Circuit concluded that it is an essential part of the State’s initial burden to prove that a person knows he has a right to refuse consent. The California courts have followed the rule that voluntariness is a question of fact to be determined from the totality of all the circumstances, and that the state of a defendant’s knowledge is only one factor to be taken into account in assessing the voluntariness of a consent. See, e. g., People v. Tremayne, 20 Cal. App. 3d 1006, 98 Cal. Rptr. 193; People v. Roberts, 246 Cal. App. 2d 715, 55 Cal. Rptr. 62.

A

The most extensive judicial exposition of the meaning of “voluntariness” has been developed in those cases in which the Court has had to determine the “voluntariness” of a defendant’s confession for purposes of the Fourteenth Amendment. Almost 40 years ago, in Brown v. Mississippi, 297 U. S. 278, the Court held that a criminal conviction based upon a confession obtained by brutality and violence was constitutionally invalid under the Due Process Clause of the Fourteenth Amendment. In some 30 different cases decided during the era that intervened between Brown and Escobedo v. Illinois, 378 U. S. 478, the Court was faced with the necessity of determining whether in fact the confessions in issue had been “voluntarily” given.5 It is to that body *224of case law to which we turn for initial guidance on the meaning of “voluntariness” in the present context.6

Those cases yield no talismanic definition of “volun-tariness,” mechanically applicable to the host of situations where the question has arisen. “The notion of ‘voluntariness,’ ” Mr. Justice Frankfurter once wrote, “is itself an amphibian.” Culombe v. Connecticut, 367 U. S. 568, 604-605. It cannot be taken literally to mean a “knowing” choice. “Except where a person is unconscious or drugged or otherwise lacks capacity for conscious choice, all incriminating statements — even those made under brutal treatment — are ‘voluntary’ in the sense of representing a choice of alternatives. On the other hand, if ‘voluntariness’ incorporates notions of ‘but-for’ cause, the question should be whether the statement would have been made even absent inquiry or other official action. Under such a test, virtually no statement would be voluntary because very few people give incriminating statements in the absence of official action of some kind.” 7 It is thus evident that neither linguistics nor epistemology will provide a ready definition of the meaning of “voluntariness.”

Rather, “voluntariness” has reflected an accommodation of the complex of values implicated in police ques*225tioning of a suspect. At one end of the spectrum is the acknowledged need for police questioning as a tool for the effective enforcement of criminal laws. See Culombe v. Connecticut, supra, at 578-580. Without such investigation, those who were innocent might be falsely accused, those who were guilty might wholly escape prosecution, and many crimes would go unsolved. In short, the security of all would be diminished. Haynes v. Washington, 373 U. S. 503, 515. At the other end of the spectrum is the set of values reflecting society’s deeply felt belief that the criminal law cannot be used as an instrument of unfairness, and that the possibility of unfair and even brutal police tactics poses a real and serious threat to civilized notions of justice. “[I]n cases involving involuntary confessions, this Court enforces the strongly felt attitude of our society that important human values are sacrificed where an agency of the government, in the course of securing a conviction, wrings a confession out of an accused against his will.” Blackburn v. Alabama, 361 U. S. 199, 206-207. See also Culombe v. Connecticut, supra, at 581-584; Chambers v. Florida, 309 U. S. 227, 235-238.

This Court’s decisions reflect a frank recognition that the Constitution requires the sacrifice of neither security nor liberty. The Due Process Clause does not mandate that the police forgo all questioning, or that they be given carte blanche to extract what they can from a suspect. “The ultimate test remains that which has been the only clearly established test in Anglo-American courts for two hundred years: the test of voluntariness. Is the confession the product of an essentially free and unconstrained choice by its maker? If it is, if he has willed to confess, it may be used against him. If it is not, if his will has been overborne and his capacity for self-determination critically impaired, the use of his *226confession offends due process.” Culombe v. Connecticut, supra, at 602.

In determining whether a defendant’s will was overborne in a particular case, the Court has assessed the totality of all the surrounding circumstances — both the characteristics of the accused and the details of the interrogation. Some of the factors taken into account have included the youth of the accused, e. g., Haley v. Ohio, 332 U. S. 596; his lack of education, e. g., Payne v. Arkansas, 356 U. S. 560; or his low intelligence, e. g., Fikes v. Alabama, 352 U. S. 191; the lack of any advice to the accused of his constitutional rights, e. g., Davis v. North Carolina, 384 U. S. 737; the length of detention, e. g., Chambers v. Florida, supra; the repeated and prolonged nature of the questioning, e. g., Ashcraft v. Tennessee, 322 U. S. 143; and the use of physical punishment such as the deprivation of food or sleep, e. g., Reck v. Pate, 367 U. S. 433.8 In all of these cases, the Court determined the factual circumstances surrounding the confession, assessed the psychological impact on the accused, and evaluated the legal significance of how the accused reacted. Culombe v. Connecticut, supra, at 603.

The significant fact about all of these decisions is that none of them turned on the presence or absence of a single controlling criterion; each reflected a careful scrutiny of all the surrounding circumstances. See Miranda v. Arizona, 384 U. S. 436, 508 (Harlan, J., dissenting) ; id., at 534-535 (White, J., dissenting). In none of them did the Court rule that the Due Process Clause required the prosecution to prove as part of its *227initial burden that the defendant knew he had a right to refuse to answer the questions that were put. While the state of the accused's mind, and the failure of the police to advise the accused of his rights, were certainly factors to be evaluated in assessing the “voluntariness” of an accused's responses, they were not in and of themselves determinative. See, e. g., Davis v. North Carolina, supra; Haynes v. Washington, supra, at 510-511; Culombe v. Connecticut, supra, at 610; Turner v. Pennsylvania, 338 U. S. 62, 64.

B

Similar considerations lead us to agree with the courts of California that the question whether a consent to a search was in fact “voluntary” or was the product of duress or coercion, express or implied, is a question of fact to be determined from the totality of all the circumstances. While knowledge of the right to refuse consent is one factor to be taken into account, the government need not establish such knowledge as the sine qua non of an effective consent. As with police questioning, two competing concerns must be accommodated in determining the meaning of a “voluntary” consent — the legitimate need for such searches and the equally important requirement of assuring the absence of coercion.

In situations where the police have some evidence of illicit activity, but lack probable cause to arrest or search, a search authorized by a valid consent may be the only means of obtaining important and reliable evidence.9 In the present case for example, while the police had reason to stop the car for traffic violations, the State does not contend that there was probable cause to search the vehicle or that the search was incident to a valid arrest *228of any of the occupants.10 Yet, the search yielded tangible evidence that served as a basis for a prosecution, and provided some assurance that others, wholly innocent of the crime, were not mistakenly brought to trial. And in those cases where there is probable cause to arrest or search, but where the police lack a warrant, a consent search may still be valuable. If the search is conducted and proves fruitless, that in itself may convince the police that an arrest with its possible stigma and embarrassment is unnecessary, or that a far more extensive search pursuant to a warrant is not justified. In short, a search pursuant to consent may result in considerably less inconvenience for the subject of the search, and, properly conducted, is a constitutionally permissible and wholly legitimate aspect of effective police activity.

But the Fourth and Fourteenth Amendments require that a consent not be coerced, by explicit or implicit means, by implied threat.or covert force. For, no matter how subtly the coercion was applied, the resulting “consent” would be no more than a pretext for the unjustified police intrusion against which the Fourth Amendment is directed. In the words of the classic admonition in Boyd v. United States, 116 U. S. 616, 635:

“It may be that it is the obnoxious thing in its mildest and least repulsive form; but illegitimate and unconstitutional practices get their first footing in that way, namely, by silent approaches and slight deviations from legal modes of procedure. This can only be obviated by adhering to the rule that constitutional provisions for the security of person and property should be liberally construed. A close *229and literal construction deprives them of half their efficacy, and leads to gradual depreciation of the right, as if it consisted more in sound than in substance. It is the duty of courts to be watchful for the constitutional rights of the citizen, and against any stealthy encroachments thereon.”

The problem of reconciling the recognized legitimacy of consent searches with the requirement that they be free from any aspect of official coercion cannot be resolved by any infallible touchstone. To approve such searches without the most careful scrutiny would sanction the possibility of official coercion; to place artificial restrictions upon such searches would jeopardize their basic validity. Just as was true with confessions, the requirement of a “voluntary” consent reflects a fair accommodation of the constitutional requirements involved. In examining all the surrounding circumstances to determine if in fact the consent to search was coerced, account must be taken of subtly coercive police questions, as well as the possibly vulnerable subjective state of the person who consents. Those searches that are the product of police coercion can thus be filtered out without undermining the continuing validity of consent searches. In sum, there is no reason for us to depart in the area of consent searches, from the traditional definition of “voluntariness.”

The approach of the Court of Appeals for the Ninth Circuit finds no support in any of our decisions that have attempted to define the meaning of “voluntariness.” Its ruling, that the State must affirmatively prove that the subject of the search knew that he had a right to refuse consent, would, in practice, create serious doubt whether consent searches could continue to be conducted. There might be rare cases where it could be proved from the record that a person in fact affirmatively knew of his *230right to refuse — such as a case where he announced to the police that if he didn't sign the consent form, “you [police] are going to get a search warrant;” 11 or a case where by prior experience and training a person had clearly and convincingly demonstrated such knowledge.12 But more commonly where there was no evidence of any coercion, explicit or implicit, the prosecution would nevertheless be unable to demonstrate that the subject of the search in fact had known of his right to refuse consent.

The very object of the inquiry — the nature of a person's subjective understanding — underlines the difficulty of the prosecution's burden under the rule applied by the Court of Appeals in this case. Any defendant who was the subject of a search authorized solely by his consent could effectively frustrate the introduction into evidence of the fruits of that search by simply failing to testify that he in fact knew he could refuse to consent. And the near impossibility of meeting this prosecutorial burden suggests why this Court has never accepted any such litmus-paper test of voluntariness. It is instructive to recall the fears of then Justice Traynor of the California Supreme Court:

“[I]t is not unreasonable for officers to seek interviews with suspects or witnesses or to call upon them at their homes for such purposes. Such inquiries, although courteously made and not accompanied with any assertion of a right to enter or search or secure answers, would permit the criminal to defeat his prosecution by voluntarily revealing all of the evidence against him and then contending that he acted only in response to an implied assertion of *231unlawful authority.” People v. Michael, 45 Cal. 2d, at 754, 290 P. 2d, at 854.

One alternative that would go far toward proving that the subject of a search did know he had a right to refuse consent would be to advise him of that right before eliciting his consent. That, however, is a suggestion that has been almost universally repudiated by both federal13 and state courts,14 and, we think, rightly so. For it would be thoroughly impractical to impose on the normal consent search the detailed requirements of an effective warning. Consent searches are part of the standard investigatory techniques of law enforcement *232agencies. They normally occur on the highway, or in a person’s home or office, and under informal and unstructured conditions. The circumstances that prompt the initial request to search may develop quickly or be a logical extension of investigative police questioning. The police may seek to investigate further suspicious circumstances or to follow up leads developed in questioning persons at the scene of a crime. These situations are a far cry from the structured atmosphere of a trial where, assisted by counsel if he chooses, a defendant is informed of his trial rights. Cf. Boykin v. Alabama, 395 U. S. 238, 243. And, while surely a closer question, these situations are still immeasurably far removed from “custodial interrogation” where, in Miranda v. Arizona, supra, we found that the Constitution required certain now familiar warnings as a prerequisite to police interrogation. Indeed, in language applicable to the typical consent search, we refused to extend the need for warnings:

“Our decision is not intended to hamper the traditional function of police officers in investigating crime. . . . When an individual is in custody on probable cause, the police may, of course, seek out evidence in the field to be used at trial against him. Such investigation may include inquiry of persons not under restraint. General on-the-scene questioning as to facts surrounding a crime or other general questioning of citizens in the fact-finding process is not affected by our holding. It is an act of responsible citizenship for individuals to give whatever information they may have to aid in law enforcement.” 384 U. S., at 477-478.

Consequently, we cannot accept the position of the Court of Appeals in this case that proof of knowledge of the right to refuse consent is a necessary prerequisite *233to demonstrating a “voluntary” consent. Rather, it is only by analyzing all the circumstances of an individual consent that it can be ascertained whether in fact it was voluntary or coerced. It is this careful sifting of the unique facts and circumstances of each case that is evidenced in our prior decisions involving consent searches.

For example, in Davis v. United States, 328 U. S. 582, federal agents enforcing wartime gasoline-rationing regulations, arrested a filling station operator and asked to see his rationing coupons. He eventually unlocked a room where the agents discovered the coupons that formed the basis for his conviction. The District Court found that the petitioner had consented to the search — that although he had at first refused to turn the coupons over, he had soon been persuaded to do so and that force or threat of force had not been employed to persuade him. Concluding that it could not be said that this finding was erroneous, this Court, in an opinion by Mr. Justice Douglas that looked to all the circumstances surrounding the consent, affirmed the judgment of conviction: “The public character of the property, the fact that the demand was made during business hours at the place of business where the coupons were required to be kept, the existence of the right to inspect, the nature of the request, the fact that the initial refusal to turn the coupons over was soon followed by acquiescence in the demand — these circumstances all support the conclusion of the District Court.” Id., at 593-594. See also Zap v. United States, 328 U. S. 624.

Conversely, if under all the circumstances it has appeared that the consent was not given voluntarily — that it was coerced by threats or force, or granted only in submission to a claim of lawful authority — then we have found the consent invalid and the search unreasonable. See, e. g., Bumper v. North Carolina, 391 U. S., at 548-549; Johnson v. United States, 333 U. S. 10; Amos v. *234 United States, 255 U. S. 313. In Bumper, a 66-year-old Negro widow, who lived in a house located in a rural area at the end of an isolated mile-long dirt road, allowed four white law enforcement officials to search her home after they asserted they had a warrant to search the house. We held the alleged consent to be invalid, noting that “[w]hen a law enforcement officer claims authority to search a home under a warrant, he announces in effect that the occupant has no right to resist the search. The situation is instinct with coercion — albeit colorably lawful coercion. Where there is coercion there cannot be consent.” 391 U. S., at 550.

Implicit in all of these cases is the recognition that knowledge of a right to refuse is not a prerequisite of a voluntary consent. If the prosecution were required to demonstrate such knowledge, Davis and Zap could not have found consent without evidence of that knowledge. And similarly if the failure to prove such knowledge were sufficient to show an ineffective consent, the Amos, Johnson, and Bumper opinions would surely have focused upon the subjective mental state of the person who consented. Yet they did not.

In short, neither this Court’s prior cases, nor the traditional definition of “voluntariness” requires proof of knowledge of a right to refuse as the sine qua non of an effective consent to a search.15

*235c

It is said, however, that a “consent” is a “waiver” of a person’s rights under the Fourth and Fourteenth Amendments. The argument is that by allowing the police to conduct a search, a person “waives” whatever right he had to prevent the police from searching. It is argued that under the doctrine of Johnson v. Zerbst, 304 U. S. 458, 464, to establish such a “waiver” the State must demonstrate “an intentional relinquishment or abandonment of a known right or privilege.”

But these standards were enunciated in Johnson in the context of the safeguards of a fair criminal trial. Our cases do not reflect an uncritical demand for a knowing and intelligent waiver in every situation where a person has failed to invoke a constitutional protection. As Mr. Justice Black once observed for the Court: “ 'Waiver’ is a vague term used for a great variety of purposes, good and bad, in the law.” Green v. United States, 355 U. S. 184, 191. With respect to procedural due process, for example, the Court has acknowledged that waiver is possible, while explicitly leaving open the question whether a “knowing and intelligent” waiver need be shown.16 See D. H. Overmyer Co. v. Frick Co., *236405 U. S. 174, 185-186; Fuentes v. Shevin, 407 TJ. S. 67, 9A-96.17

The requirement of a “knowing” and “intelligent” waiver was articulated in a case involving the validity of a defendant’s decision to forgo a right constitutionally guaranteed to protect a fair trial and the reliability of the truth-determining process. Johnson v. Zerbst, supra, dealt with the denial of counsel in a federal criminal trial. There the Court held that under the Sixth Amendment a criminal defendant is entitled to the assistance of counsel, and that if he lacks sufficient funds to retain counsel, it is the Government’s obligation to furnish him with a lawyer. As Mr. Justice Black wrote for the Court: “The Sixth Amendment stands as a constant admonition that if the constitutional safeguards it provides be lost, justice will not ‘still be done.’ It embodies a realistic recognition of the obvious truth that the average defendant does not have the professional legal skill to protect himself when brought before a tribunal with power to take his life or liberty, wherein the prosecution is presented by experienced and learned counsel. That which is simple, orderly and necessary to the lawyer, to the untrained layman may appear intricate, complex and mysterious.” 304 TJ. S., at 462-463 (footnote omitted). To preserve the fairness of the trial process the Court established an appropriately heavy burden on the Government before waiver could be found — “an in*237tentional relinquishment or abandonment of a known right or privilege.” Id., at 464.

Almost without exception, the requirement of a knowing and intelligent waiver has been applied only to those rights which the Constitution guarantees to a criminal defendant in order to preserve a fair trial.18 Hence, and hardly surprisingly in view of the facts of Johnson itself, the standard of a knowing and intelligent waiver has most often been applied to test the validity of a waiver of counsel, either at trial,19 or upon a guilty plea.20 And the Court has also applied the Johnson criteria to assess the effectiveness of a waiver of other trial rights such as the right to confrontation,21 to a jury trial,22 and to a speedy trial,23 and the right to be free from *238twice being placed in jeopardy.24 Guilty pleas have been carefully scrutinized to determine whether the accused knew and understood all the rights to which he would be entitled at trial, and that he had intentionally chosen to forgo them.25 And the Court has evaluated the knowing and intelligent nature of the waiver of trial rights in trial-type situations, such as the waiver of the privilege against compulsory self-incrimination before an administrative agency26 or a congressional committee,27 or the waiver of counsel in a juvenile proceeding.28

The guarantees afforded a criminal defendant at trial also protect him at certain stages before the actual trial, and any alleged waiver must meet the strict standard of an intentional relinquishment of a “known” right. But the “trial” guarantees that have been applied to the “pre*239trial” stage of the criminal process are similarly designed to protect the fairness of the trial itself.

Hence, in United States v. Wade, 388 U. S. 218, and Gilbert v. California, 388 U. S. 263, the Court held “that a post-indictment pretrial lineup at which the accused is exhibited to identifying witnesses is a critical stage of the criminal prosecution; that police conduct of such a lineup without notice to and in the absence of his counsel denies the accused his Sixth [and Fourteenth] Amendment right to counsel . . . Id., at 272. Accordingly, the Court indicated that the standard of a knowing and intelligent waiver must be applied to test the waiver of counsel at such a lineup. See United States v. Wade, supra, at 237. The Court stressed the necessary interrelationship between the presence of counsel at a post-indictment lineup before trial and the protection of the trial process itself:

“Insofar as the accused's conviction may rest on a courtroom identification in fact the fruit of a suspect pretrial identification which the accused is helpless to subject to effective scrutiny at trial, the accused is deprived of that right of cross-examination which is an essential safeguard to his right to confront the witnesses against him. Pointer v. Texas, 380 U. S. 400. And even though cross-examination is a precious safeguard to a fair trial, it cannot be viewed as an absolute assurance of accuracy and reliability. Thus in the present context, where so many variables and pitfalls exist, the first line of defense must be the prevention of unfairness and the lessening of the hazards of eyewitness identification at the lineup itself. The trial which might determine the accused’s fate may well not be that in the courtroom but that at the pretrial confrontation, with the State aligned against the accused, the *240witness the sole jury, and the accused unprotected against the overreaching, intentional or unintentional, and with little or no effective appeal from the judgment there rendered by the witness — ‘that's the man.’ ” Id., at 235-236.

And in Miranda v. Arizona, 384 U. S. 436, the Court found that custodial interrogation by the police was inherently coercive, and consequently held that detailed warnings were required to protect the privilege against compulsory self-incrimination. The Court made it clear that the basis for decision was the need to protect the fairness of the trial itself:

“That counsel is present when statements are taken from an individual during interrogation obviously enhances the integrity of the fact-finding processes in court. The presence of an attorney, and the warnings delivered to the individual, enable the defendant under otherwise compelling circumstances to tell his story without fear, effectively, and in a way that eliminates the evils in the interrogation process. Without the protections flowing from adequate warnings and the rights of counsel, ‘all the careful safeguards erected around the giving of testimony, whether by an accused or any other witness, would become empty formalities in a procedure where the most compelling possible evidence of guilt, a confession, would have already been obtained at the unsupervised pleasure of the police.’ ” Id., at 466.

The standards of Johnson were, therefore, found to be a necessary prerequisite to a finding of a valid waiver. See 384 U. S., at 475-479. Cf. Escobedo v. Illinois, 378 U. S., at 490 n. 14.29

*241There is a vast difference between those rights that protect a fair criminal trial and the rights guaranteed under the Fourth Amendment. Nothing, either in the purposes behind requiring a “knowing” and “intelligent” waiver of trial rights, or in the practical application of such a requirement suggests that it ought to be extended to the constitutional guarantee against unreasonable searches and seizures.

A strict standard of waiver has been applied to those rights guaranteed to a criminal defendant to insure that he will be accorded the greatest possible opportunity to utilize every facet of the constitutional model of a fair criminal trial. Any trial conducted in derogation of that model leaves open the possibility that the trial reached an unfair result precisely because all the protections specified in the Constitution were not provided. A prime example is the right to counsel. For without that right, a wholly innocent accused faces the real and substantial danger that simply because of his lack of legal expertise he may be convicted. As Mr. Justice Harlan once wrote: “The sound reason why [the right to counsel] is so freely extended for a criminal trial is the severe injustice risked by confronting an untrained defendant with a range of technical points of law, evidence, and tactics familiar to the prosecutor but not to *242himself.” Miranda v. Arizona, supra, at 514 (dissenting opinion). The Constitution requires that every effort be made to see to it that a defendant in a criminal case has not unknowingly relinquished the basic protections that the Framers thought indispensable to a fair trial.30

The protections of the Fourth Amendment are of a wholly different order, and have nothing whatever to do with promoting the fair ascertainment of truth at a criminal trial. Rather, as Mr. Justice Frankfurter’s opinion for the Court put it in Wolf v. Colorado,, 338 U. S. 25, 27, the Fourth Amendment protects the “security of one’s privacy against arbitrary intrusion by the police . . . .” In declining to apply the exclusionary rule of Mapp v. Ohio, 367 U. S. 643, to convictions that had become final before rendition of that decision, the Court emphasized that “there is no likelihood of unreliability or coercion present in a search-and-seizure case,” Linkletter v. Walker, 381 U. S. 618, 638. In Link-letter, the Court indicated that those cases that had been given retroactive effect went to “the fairness of the trial — the very integrity of the fact-finding process. Here . . . the fairness of the trial is not under attack.” Id., at 639. The Fourth Amendment “is not an adjunct to the ascertainment of truth.” The guarantees of the Fourth Amendment stand “as a protection of quite different constitutional values — values reflecting the concern of our society for the right of each individual to be let alone. To recognize this is no more than to accord those values undiluted respect.” Tehan v. United States ex rel. Shott, 382 U. S. 406, 416.

Nor can it even be said that a search, as opposed to an eventual trial, is somehow “unfair” if a person consents to a search. While the Fourth and Fourteenth *243Amendments limit the circumstances under which the police can conduct a search, there is nothing constitutionally suspect in a person’s voluntarily allowing a search. The actual conduct of the search may be precisely the same as if the police had obtained a warrant. And, unlike those constitutional guarantees that protect a defendant at trial, it cannot be said every reasonable presumption ought to be indulged against voluntary relinquishment. We have only recently stated: “[I]t is no part of the policy underlying the Fourth and Fourteenth Amendments to discourage citizens from aiding to the utmost of their ability in the apprehension of criminals.” Coolidge v. New Hampshire, 403 U. S., at 488. Rather, the community has a real interest in encouraging consent, for the resulting search may yield necessary evidence for the solution and prosecution of crime, evidence that may insure that a wholly innocent person is not wrongly charged with a criminal offense.

Those cases that have dealt with the application of the Johnson v. Zerbst rule make clear that it would be next to impossible to apply to a consent search the standard of “an intentional relinquishment or abandonment of a known right or privilege.” 31 To be true to Johnson *244and its progeny, there must be examination into the knowing and understanding nature of the waiver, an examination that was designed for a trial judge in the structured atmosphere of a courtroom. As the Court expressed it in Johnson:

"The constitutional right of an accused to be represented by counsel invokes, of itself, the protection of a trial court, in which the accused — whose life or liberty is at stake — is without counsel. This protecting duty imposes the serious and weighty responsibility upon the trial judge of determining whether there is an intelligent and competent waiver by the accused. While an accused may waive the right to counsel, whether there is a proper waiver should be clearly determined by the trial court, and it would be fitting and appropriate for that determination to appear upon the record.” 304 U. S., at 465.32

*245It would be unrealistic to expect that in the informal, unstructured context of a consent search, a policeman, upon pain of tainting the evidence obtained, could make the detailed type of examination demanded by Johnson. And, if for this reason a diluted form of “waiver” were found acceptable, that would itself be ample recognition of the fact that there is no universal standard that must be applied in every situation where a person forgoes a constitutional right.33

Similarly, a “waiver” approach to consent searches would be thoroughly inconsistent with our decisions that have approved “third party consents.” In Coolidge v. New Hampshire, 403 U. S., at 487-490, where a wife surrendered to the police guns and clothing belonging to her husband, we found nothing constitutionally impermissible in the admission of that evidence at trial since the wife had not been coerced. Frazier v. Cupp, 394 U. S. 731, 740, held that evidence seized from the defendant's duffel bag in a search authorized by his cousin’s consent was admissible at trial. We found that the defendant had assumed the risk that his cousin, with whom he shared the bag, would allow the police to search it. See also Abel v. United States, 362 U. S. 217. And *246in Hill v. California, 401 U. S. 797, 802-805, we held that the police had validly seized evidence from the petitioner’s apartment incident to the arrest of a third party, since the police had probable cause to arrest the petitioner and reasonably, though mistakenly, believed the man they had arrested was he. Yet it is inconceivable that the Constitution could countenance the waiver of a defendant’s right to counsel by a third party, or that a waiver could be found because a trial judge reasonably, though mistakenly, believed a defendant had waived his right to plead not guilty.34

In short, there is nothing in the purposes or application of the waiver requirements of Johnson v. Zerbst that justifies, much less compels, the easy equation of a knowing waiver with a consent search. To make such an equation is to generalize from the broad rhetoric of some of our decisions, and to ignore the substance of the differing constitutional guarantees. We decline to follow what one judicial scholar has termed “the domino method of constitutional adjudication . . . wherein every explanatory statement in a previous opinion is made the basis for extension to a wholly different situation.” 35

D

Much of what has already been said disposes of the argument that the Court’s decision in the Miranda case requires the conclusion that knowledge of a right to refuse is an indispensable element of a valid consent. The considerations that informed the Court’s holding in Miranda are simply inapplicable in the present case. *247In Miranda the Court found that the techniques of police questioning and the nature of custodial surroundings produce an inherently coercive situation. The Court concluded that “[ujnless adequate protective devices are employed to dispel the compulsion inherent in custodial surroundings, no statement obtained from the defendant can truly be the product of his free choice.” 384 U. S., at 458. And at another point the Court noted that “without proper safeguards the process of in-custody interrogation of persons suspected or accused of crime contains inherently compelling pressures which work to undermine the individual’s will to resist and to compel him to speak where he would not otherwise do so freely.” Id., at 467.

In this case, there is no evidence of any inherently coercive tactics — either from the nature of the police questioning or the environment in which it took place. Indeed, since consent searches will normally occur on a person’s own familiar territory, the specter of incommunicado police interrogation in some remote station house is simply inapposite.36 There is no reason to believe, under circumstances such as are present here, that the response to a policeman’s question is presumptively coerced; and there is, therefore, no reason to reject the traditional test for determining the voluntariness of a person’s response. Miranda, of course, did not reach investigative questioning of a person not in custody, which is most directly analogous to the situation of a consent search, and it assuredly did not indicate that such questioning ought to be deemed inherently coercive. See su-pra, at 232.

It is also argued that the failure to require the Government to establish knowledge as a prerequisite to a valid *248consent, will relegate the Fourth Amendment to the special province of “the sophisticated, the knowledgeable and the privileged.” We cannot agree. The traditional definition of voluntariness we accept today has always taken into account evidence of minimal schooling, low intelligence, and the lack of any effective warnings to a person of his,rights; and the voluntariness of any statement taken under those conditions has been carefully scrutinized to determine whether it was in fact voluntarily given.37

E

Our decision today is a narrow one. We hold only that when the subject of a search is not in custody and the State attempts to justify a search on the basis of his consent, the Fourth and Fourteenth Amendments require that it demonstrate that the consent was in fact voluntarily given, and not the result of duress or coercion, express or implied. Voluntariness is a question of fact *249to be determined from all the circumstances, and while the subject’s knowledge of a right to refuse is a factor to be taken into account, the prosecution is not required to demonstrate such knowledge as a prerequisite to establishing a voluntary consent.38 Because the California court followed these principles in affirming the respondent’s conviction, and because the Court of Appeals for the Ninth Circuit in remanding for an evidentiary hearing required more, its judgment must be reversed.

It is so ordered.

Mr. Justice Blackmun,

concurring.

I join the Court’s opinion and its judgment.

At the time Kaufman v. United States, 394 U. S. 217 (1969), was decided, I, as a member of the Court of Appeals (but not of its panel) whose order was there reversed, found myself in agreement with the views expressed by Mr. Justice Harlan, writing for himself and my Brother Stewart in dissent. Id., at 242. My attitude has not changed in the four years that have passed since Kaufman was decided.

Although I agree with nearly all that Mr. Justice Powell has to say in his detailed and persuasive concurring opinion, post, p. 250, I refrain from joining it at this time because, as Mr. Justice Stewart’s opinion reveals, it is not necessary to reconsider Kaufman in order to decide the present case.

*250Mr. Justice Powell,

with whom The Chief Justice and Mr. Justice Rehnquist join, concurring.

While I join the opinion of the Court, it does not address what seems to me the overriding issue briefed and argued in this case: the extent to which federal habeas corpus should be available to a state prisoner seeking to exclude evidence from an allegedly unlawful search and seizure. I would hold that federal collateral review of a state prisoner’s Fourth Amendment claims — claims which rarely bear on innocence — should be confined solely to the question of,whether the petitioner was provided a fair opportunity to raise and have adjudicated the question in state courts. In view of the importance of this issue to our system of criminal justice, I think it appropriate to express my views.

I

Although petitions for federal habeas corpus assert a wide variety of constitutional questions, we are concerned in this case only with a Fourth Amendment claim that an unlawful search occurred and that the state court erred in failing to exclude the evidence obtained therefrom. A divided court in Kaufman v. United States, 394 U. S. 217 (1969), held that collateral review of search-and-seizure claims was appropriate on motions filed by federal prisoners under 28 U. S. C. § 2255. Until Kaufman, a substantial majority of the federal courts of appeals had considered that claims of unlawful search and seizure “ 'are not proper matters to be presented by a motion to vacate sentence under § 2255 ....’” Id., at 220. The rationale of this view was fairly summarized by the Court:

“The denial of Fourth Amendment protection against unreasonable searches and seizures, the Gov*251ernment’s argument runs, is of a different nature from denials of other constitutional rights which we have held subject to collateral attack by federal prisoners. For unlike a claim of denial of effective counsel or of violation of the privilege against self incrimination, as examples, a claim of illegal search and seizure does not impugn the integrity of the fact-finding process or challenge evidence as inherently unreliable; rather, the exclusion of illegally seized evidence is simply a prophylactic device intended generally to deter Fourth Amendment violations by law enforcement officers.” Id., at 224.

In rejecting this rationale, the Court noted that under prior decisions “the federal habeas remedy extends to state prisoners alleging that unconstitutionally obtained evidence was admitted against them at trial,”1 and concluded that there was no basis for restricting “access by federal prisoners with illegal search-and-seizure claims to federal collateral remedies, while placing no similar restriction on access by state prisoners.” Id., at 225-226. In short, on petition for habeas corpus or collateral review filed in a federal district court, whether by state prisoners under 28 U. S. C. § 2254 or federal prisoners under § 2255, the present rule is that Fourth Amendment claims may be asserted and the exclusionary rule must be applied in precisely the same manner as on direct review. Neither the history or purpose of habeas corpus, the desired prophylactic utility of the exclusionary rule as applied to Fourth Amendment claims, nor any sound reason relevant to the administration of criminal justice in our federal system justifies such a power.

*252II

The federal review involved in this Fourth Amendment case goes well beyond the traditional purpose of the writ of habeas corpus. Much of the present perception of habeas corpus stems from a revisionist view of the historic function that writ was meant to perform. The critical historical argument has focused on the nature of the writ at the time of its incorporation in our Constitution and at the time of the Habeas Corpus Act of 1867, the direct ancestor of contemporary habeas corpus statutes.2 In Fay v. Nota, 372 U. S. 391, 426 (1963), the Court interpreted the writ’s historic position as follows:

"At the time the privilege of the writ was written into the Federal Constitution it was settled that the writ lay to test any restraint contrary to fundamental law, which in England stemmed ultimately from Magna Charta but in this country was embodied in the written Constitution. Congress in 1867 sought to provide a federal forum for state prisoners having constitutional defenses by extending the habeas corpus powers of the federal courts to their constitutional maximum. Obedient to this purpose, we have consistently held that federal court *253jurisdiction is conferred by the allegation of an unconstitutional restraint and is not defeated by anything that may occur in the state court proceedings.”

If this were a correct interpretation of the relevant history, the present wide scope accorded the writ would have arguable support, despite the impressive reasons to the contrary. But recent scholarship has cast grave doubt on Fay’s version of the writ’s historic function.

It has been established that both the Framers of the Constitution and the authors of the 1867 Act expected that the scope of habeas corpus would be determined with reference to the writ’s historic, common-law development.3 Mr. Chief Justice Marshall early referred to the common-law conception of the writ in determining its constitutional and statutory scope, Ex parte Bollman, 4 Cranch 75, 93-94 (1807); Ex parte Watkins, 3 Pet. 193, 201-202 (1830), and Professor Oaks has noted that “when the 1867 Congress provided that persons restrained of their liberty in violation of the Constitution could obtain a writ of habeas corpus from a federal court, it undoubtedly intended — except to the extent the legislation provided otherwise — to incorporate the common-law uses and functions of this remedy.” 4

It thus becomes important to understand exactly what was the common-law scope of the writ both when embraced by our Constitution and incorporated into the Habeas Corpus Act of 1867. Two respected scholars have recently explored precisely these questions.5 Their efforts *254have been both meticulous and revealing. Their conclusions differ significantly from those of the Court in Fay v. Noia, that habeas corpus traditionally has been available “to remedy any kind of governmental restraint contrary to fundamental law.” 372 U. S., at 405.

The considerable evidence marshaled by these scholars need not be restated here. Professor Oaks makes a convincing case that under the common law of habeas corpus at the time of the adoption of the Constitution, “once a person had been convicted by a superior court of general jurisdiction, a court disposing of a habeas corpus petition could not go behind the conviction for any purpose other than to verify the formal jurisdiction of the committing court.” 6 Certainly that was what Mr. Chief Justice Marshall understood when he stated:

“This writ {habeas corpus] is, as has been said, in the nature of a writ of error which brings up the body of the prisoner with the cause of commitment. The court can undoubtedly inquire into the sufficiency of that cause; but if it be the judgment of a court of competent jurisdiction, especially a judgment withdrawn by law from the revision of this court, is not that judgment in itself sufficient cause? Can the court, upon this writ, look beyond the judgment, and re-examine the charges on which it was rendered. A judgment, in its nature, concludes the subject on which it is rendered, and pronounces the law of the case. The judgment of a court of record whose jurisdiction is final, is as conclusive on all the world as the judgment of this court would be. It is as conclusive on this court as it is on other courts. It puts an end to inquiry concerning the fact, by deciding it.” Ex parte Watkins, 3 Pet., at 202-203.

*255The respect shown under common law for the finality of the judgment of a committing court at the time of the Constitution and in the early 19th century did not, of course, explicitly contemplate the operation of habeas corpus in the context of federal-state relations. Federal habeas review for state prisoners was not available until passage of the Habeas Corpus Act of 1867. Yet there is no evidence that Congress intended that Act to jettison the respect theretofore shown by a reviewing court for prior judgments by a court of proper jurisdiction. The Act “received only the most perfunctory attention and consideration in the Congress; indeed, there were complaints that its effects could not be understood at all.” 7 In fact, as Professor Bator notes, it would require overwhelming evidence, which simply is not present, to conclude that the 1867 Congress intended “to tear habeas corpus entirely out of the context of its historical meaning and scope and convert it into an ordinary writ of error with respect to all federal questions in all criminal cases.” 8 Rather, the House Judiciary Committee when it reviewed the Act in 1884 understood that it was not “contemplated by its framers or . . . properly . . . construed to authorize the overthrow of the final judgments of the State courts of general jurisdiction, by the inferior Federal judges. ...”9

Much, of course, has transpired since that first Habeas Corpus Act. See Fay v. Noia, 372 U. S., at 449-463 (Harlan, J., dissenting). The scope of federal habeas corpus for state prisoners has evolved from a quite limited inquiry into whether the committing state court had jurisdiction, Andrews v. Swartz, 156 U. S. 272 (1895); In re *256 Moran, 203 U. S. 96 (1906), to whether the applicant had been given an adequate opportunity in state court to raise his constitutional claims, Frank v. Mangum, 237 U. S. 309 (1915); and finally to actual redetermination in federal court of state court rulings on a wide variety of constitutional contentions, Brown v. Allen, 344 U. S. 443 (1953). No one would now suggest that this Court be imprisoned by every particular of habeas corpus as it existed in the late 18th and 19th centuries. But recognition of that reality does not liberate us from all historical restraint. The historical evidence demonstrates that the purposes of the writ, at the time of the adoption of the Constitution, were tempered by a due regard for the finality of the judgment of the committing court. This regard was maintained substantially intact when Congress, in the Habeas Corpus Act of 1867, first extended federal habeas review to the delicate interrelations of our dual court systems.

Ill

Recent decisions, however, have tended to depreciate the importance of the finality of prior judgments in criminal cases. Kaufman, 394 U. S., at 228; Sanders v. United States, 373 U. S. 1, 8 (1963); Fay, supra, at 424. This trend may be a justifiable evolution of the use of habeas corpus where the one in state custody raises a constitutional claim bearing on his innocence. But the justification for disregarding the historic scope and function of the writ is measurably less apparent in the typical Fourth Amendment claim asserted on collateral attack. In this latter case, a convicted defendant is most often asking society to redetermine a matter with no bearing at all on the basic justice of his incarceration.

Habeas corpus indeed should provide the added assurance for a free society that no innocent man suffers an unconstitutional loss of liberty. The Court in Fay described *257habeas corpus as a remedy for “whatever society deems to be intolerable restraints,” and recognized that those to whom the writ should be granted “are persons whom society has grievously wronged and for whom belated liberation is little enough compensation.” Id., at 401-402, 441. The Court there acknowledged that the central reason for the writ lay in remedying injustice to the individual. Recent commentators have recognized the same core concept, one noting that “where person-al liberty is involved, a democratic society . . . insists that it is less important to reach an unshakable decision than to do justice (emphasis added),”10 and another extolling the use of the writ in Leyra v. Denno, 347 U. S. 556 (1954), with the assertion that “[b]ut for federal habeas corpus, these two men would have gone to their deaths for crimes of which they were found not guilty.” 11

I am aware that history reveals no exact tie of the writ of habeas corpus to a constitutional claim relating to innocence or guilt. Traditionally, the writ was unavailable even for many constitutional pleas grounded on a claimant’s innocence, while many contemporary proponents of expanded employment of the writ would permit its issuance for one whose deserved confinement was never in doubt. We are now faced, however, with the task of accommodating the historic respect for the finality of the judgment of a committing court with recent Court expansions of the role of the writ. This accommodation can best be achieved, with due regard to all of the values implicated, by recourse to the central reason for habeas corpus: the affording of means, *258through an extraordinary writ, of redressing an unjust incarceration.

Federal habeas review of search and seizure claims is rarely relevant to this reason. Prisoners raising Fourth Amendment claims collaterally usually are quite justly detained. The evidence obtained from searches and seizures is often “the clearest proof of guilt” with a very high content of reliability.12 Rarely is there any contention that the search rendered the evidence unreliable or that its means cast doubt upon the prisoner’s guilt. The words of Mr. Justice Black drive home the point:

“A claim of illegal search and seizure under the Fourth Amendment is crucially different from many other constitutional rights; ordinarily the evidence seized can in no way have been rendered untrustworthy by the means of its seizure and indeed often this evidence alone establishes beyond virtually any shadow of a doubt that the defendant is guilty.” Kaufman v. United States, 394 U. S., at 237 (1969) (dissenting opinion).

Habeas corpus review of search and seizure claims thus brings a deficiency of our system of criminal justice into sharp focus: a convicted defendant asserting no constitutional claim bearing on innocence and relying solely on an alleged unlawful search, is now entitled to federal habeas review of state conviction and the likelihood of release if the reviewing court concludes that the search was unlawful. That federal courts would actually redetermine constitutional claims bearing no relation to the prisoner’s innocence with the possibility of releasing him from custody if the search is held unlawful not only defeats our societal interest in a rational legal system but serves no compensating ends of personal justice.

*259IV

This unprecedented extension of habeas corpus far beyond its historic bounds and in disregard of the writ’s central purpose is an anomaly in our system sought to be justified only by extrinsic reasons which will be addressed in Part Y of this opinion. But first let us look at the costs of this anomaly — costs in terms of serious intrusions on other societal values. It is these other values that have been subordinated — not to further justice on behalf of arguably innocent persons but all too often to serve mechanistic rules quite unrelated to justice in a particular case. Nor are these neglected values unimportant to justice in the broadest sense or to our system of Government. They include (i) the most effective utilization of limited judicial resources, (ii) the necessity of finality in criminal trials, (iii) the minimization of friction between our federal and state systems of justice, and (iv) the maintenance of the constitutional balance upon which the doctrine of federalism is founded.

When raised on federal habeas, a claim generally has been considered by two or more tiers of state courts. It is the solemn duty of these courts, no less than federal ones, to safeguard personal liberties and consider federal claims in accord with federal law. The task which federal courts are asked to perform on habeas is thus most often one that has or should have been done before. The presumption that “if a job can be well done once, it should not be done twice” is sound and one calculated to utilize best “the intellectual, moral, and political resources involved in the legal system.” 13

*260Those resources are limited but demand on them constantly increases. There is an insistent call on federal courts both in civil actions, many novel and complex, which affect intimately the lives of great numbers of people and in original criminal trials and appeals which deserve our most careful attention.14 To the extent the federal courts are required to re-examine claims on collat*261eral attack,15 they deprive primary litigants of their prompt availability and mature reflection. After all, the resources of our system are finite: their overextension jeopardizes the care and quality essential to fair adjudication.

The present scope of federal habeas corpus also has worked to defeat the interest of society in a rational point of termination for criminal litigation. Professor Amsterdam has identified some of the finality interests at stake in collateral proceedings:

“They involve (a) duplication of judicial effort; (b) delay in setting the criminal proceeding at rest; (c) inconvenience and possibly danger in transporting a prisoner to the sentencing court for hearing; (d) postponed litigation of fact, hence litigation which will often be less reliable in reproducing the facts (i) respecting the postconviction claim itself, and (ii) respecting the issue of guilt if the collateral attack succeeds in a form which allows retrial. . . .”

He concluded that:

“[I]n combination, these finality considerations amount to a more or less persuasive argument against the cognizability of any particular collateral *262claim, the strength of the argument depending upon the nature of the claim, the manner' of its treatment (if any) in the conviction proceedings, and the circumstances under which collateral litigation must be had.” 16

No effective judicial system can afford to concede the continuing theoretical possibility that there is error in every trial and that every incarceration is unfounded. At some point the law must convey to those in custody that a wrong has been committed, that consequent punishment has been imposed, that one should no longer look back with the view to resurrecting every imaginable basis for further litigation but rather should look forward to rehabilitation and to becoming a constructive citizen.17

Nowhere should the merit of this view be more self-evident than in collateral attack on an allegedly unlawful search and seizure, where the petitioner often asks society to redetermine a claim with no relationship at all to the justness of his confinement. Professor Amsterdam has noted that “for reasons which are common to all search and seizure claims,” he “would hold even a slight finality interest sufficient to deny the collateral remedy.” 18 But, in fact, a strong finality interest militates against allow*263ing collateral review of search-and-seizure claims. Apart from the duplication of resources inherent in most habeas corpus proceedings, the validity of a search-and-seizure claim frequently hinges on a complex matrix of events which may be difficult indeed for the habeas court to disinter especially where, as often happens, the trial occurred years before the collateral attack and the state record is thinly sketched.19

Finally, the present scope of habeas corpus tends to undermine the values inherent in our federal system of government. To the extent that every state criminal judgment is to be subject indefinitely to broad and repetitive federal oversight, we render the actions of state courts a serious disrespect in derogation of the constitutional balance between the two systems.20 The present expansive scope of federal habeas review has prompted no small friction between state and federal judiciaries. Justice Paul C. Reardon of the Massachusetts Supreme *264Judicial Court and then President of the National Center for State Courts, in identifying problems between the two systems, noted bluntly that “[t]he first, without question, is the effect of Federal habeas corpus proceedings on State courts.” He spoke of the “humiliation of review from the full bench of the highest State appellate court to a single United States District Court judge.” Such broad federal habeas powers encourage in his view the “growing denigration of the State courts and their functions in the public mind.” 21 In so speaking Justice Reardon echoed the words of Professor Bator:

“I could imagine nothing more subversive of a judge’s sense of responsibility, of the inner subjective conscientiousness which is so essential a part of the difficult and subtle art of judging well, than an in*265discriminate acceptance of the notion that all the shots will always be called by someone else.” 22

In my view, this Court has few more pressing responsibilities than to restore the mutual respect and the balanced .sharing of responsibility between the state and federal courts which our tradition and the Constitution itself so wisely contemplate. This can be accomplished without retreat from our inherited insistence that the writ of habeas corpus retain its full vitality as a means of redressing injustice.

This case involves only a relatively narrow aspect of the appropriate reach of habeas corpus. The specific issue before us, and the only one that need be decided at this time, is the extent to which a state prisoner may obtain federal habeas corpus review of a Fourth Amendment claim. Whatever may be formulated as a more comprehensive answer to the important broader issues (whether by clarifying legislation or in subsequent decisions), Mr. Justice Black has suggested what seems to me to be the appropriate threshold requirement in a case of this kind:

“I would always require that the convicted defendant raise the kind of constitutional claim that casts some shadow of a doubt on his guilt.” Kaufman v. United States, 394 U. S., at 242 (dissenting opinion).

In a perceptive analysis, Judge Henry J. Friendly expressed a similar view. He would draw the line against habeas corpus review in the absence of a “colorable claim of innocence”:

“[W]ith a few important exceptions, convictions should be subject to collateral attack only when *266the prisoner supplements his constitutional plea with a colorable claim of innocence.” 23

Where there is no constitutional claim bearing on innocence, the inquiry of the federal court on habeas review of a state prisoner’s Fourth Amendment claim should be confined solely to the question whether the defendant was provided a fair opportunity in the state courts to raise and have adjudicated the Fourth Amendment claim. Limiting the scope of habeas review in this manner would reduce the role of the federal courts in determining the merits of constitutional claims with no relation to a petitioner’s innocence and contribute to the restoration of recently neglected values to their proper place in our criminal justice system.

Y

The importance of the values referred to above is not questioned. What, then, is the reason which has prompted this Court in recent decisions to extend habeas corpus to Fourth Amendment claims largely in disregard of its history as well as these values? In addressing Mr. Justice Black’s dissenting view that constitutional claims raised collaterally should be relevant to the petitioner’s innocence, the majority in Kaufman noted:

“It [Mr. Justice Black’s view] brings into question the propriety of the exclusionary rule itself. The application of that rule is not made to turn on the *267existence of a possibility of innocence; rather, exclusion of illegally obtained evidence is deemed necessary to protect the right of all citizens, not merely the citizen on trial, to be secure against unreasonable searches and seizures.” 394 U. S., at 229. (Emphasis added.)

The exclusionary rule has occasioned much criticism, largely on grounds that its application permits guilty defendants to go free and law-breaking officers to go unpunished.24 The oft-asserted reason for the rule is to deter illegal searches and seizures by the police, Elkins v. United States, 364 U. S. 206, 217 (1960); Mapp v. Ohio, 367 TJ. S. 643, 656 (1961) ; Linkletter v. Walker, 381 U. S. 618, 636 (1965); Terry v. Ohio, 392 U. S. 1, 29 (1968).25 *268The efficacy of this deterrent function, however, has been brought into serious question by recent empirical research. Whatever the rule’s merits on an initial trial and appeal26 — a question not in issue here — the case for *269collateral application of the rule is an anemic one. On collateral attack, the exclusionary rule retains its major liabilities while the asserted benefit of the rule dissolves. For whatever deterrent function the rule may serve when applied on trial and appeal becomes greatly attenuated when, months or years afterward, the claim surfaces for collateral review. The impermissible conduct has long since occurred, and the belated wrist slap of state police by federal courts harms no one but society on whom the convicted criminal is newly released.27

Searches and seizures are an opaque area of the law: flagrant Fourth Amendment abuses will rarely escape detection but there is a vast twilight zone with respect to which one Justice has stated that our own “decisions . . . are hardly notable for their predictability,” 28 and another has observed that this Court was “ 'bifurcating elements too infinitesimal to be split.’ ” 29 Serious Fourth Amendment infractions can be dealt with by state judges or by this Court on direct review. But the nonfrivolous Fourth Amendment claims that survive for collateral attack are most likely to be in this grey, twilight area, where the law is difficult for courts to apply, let alone for the policeman on the beat to understand. This is. *270precisely the type of case where the deterrent function of the exclusionary rule is least efficacious, and where there is the least justification for freeing a duly convicted defendant.30

Our decisions have not encouraged the thought that what may be an appropriate constitutional policy in one context automatically becomes such for all times and all seasons. In Linkletter v. Walker, 381 U. S., at 629, the Court recognized the compelling practical considerations against retroactive application of the exclusionary rule. Rather than viewing the rule as having eternal constitutional verity, the Court decided to

“weigh the merits and demerits in each case by looking to the prior history of the rule in question, its purpose and effect, and whether retrospective operation will further or retard its operation. We believe that this approach is particularly correct with reference to the Fourth Amendment’s prohibitions as to unreasonable searches and seizures.” Id., at 629.

Such a pragmatic approach compelled the Court to conclude that the rule’s deterrent function would not be advanced by its retrospective application:

“The misconduct of the police prior to Mapp has already occurred and will not be corrected by releasing the prisoners involved. . . . Finally, the ruptured privacy of the victims’ homes and effects cannot be restored. Reparation comes too late.” Id., at 637.

See also Desist v. United States, 394 U. S. 244 (1969).

The same practical, particularized analysis of the exclusionary rule’s necessity also was evident in Walder v. United States, 347 U. S. 62 (1954), when the Court per*271mitted the Government to utilize unlawfully seized evidence to impeach the credibility of a defendant who had first testified broadly in his own defense. The Court held, in effect, that the policies protected by the exclusionary rule were outweighed in this case by the need to prevent perjury and assure the integrity of proceedings at trial. The Court concluded that to apply the exclusionary rule in such circumstances “would be a perversion of the Fourth Amendment.” Id., at 65. The judgment in Walder revealed most pointedly that the policies behind the exclusionary rule are neither absolute nor all-encompassing, but rather must be weighed and balanced against a competing and more compelling policy, namely the need for effective determination of truth at trial.

In sum: the case for the exclusionary rule varies with the setting in which it is imposed. It makes little sense to extend the Mapp exclusionary rule to a federal habeas proceeding where its asserted deterrent effect must be least efficacious, and its obvious harmful consequences persist in full force.

VI

The final inquiry is whether the above position conforms to 28 U. S. C. § 2254 (a) which provides:

“The Supreme Court, a Justice thereof, a circuit judge, or a district court shall entertain an application for a writ of habeas corpus in behalf of a person in custody pursuant to the judgment of a State court only on the ground that he is in custody in violation of the Constitution or laws or treaties of the United States.”

The trend in recent years has witnessed a proliferation of constitutional rights, “a vast expansion of the claims of error in criminal cases for which a resourceful defense lawyer can find a constitutional basis.” 31 Federal ha-*272beas jurisdiction has been extended far beyond anyone’s expectation or intendment when the concept of “custody in violation of the Constitution,” now in § 2254 (a), first appeared in federal law over a century ago.32

Mr. Justice Black was clearly correct in noting that “not every conviction based in part on a denial of a constitutional right is subject to attack by habeas corpus or § 2255 proceedings after a conviction has become final.” Kaufman, 394 U. S., at 232 (dissenting opinion). No evidence exists that Congress intended every allegation of a constitutional violation to afford an appropriate basis for collateral review: indeed, the latest revisions of the Federal Habeas Corpus statute in 1966 33 and the enactment of § 2254 (a) came at the time a majority of the courts of appeals held that claims of unlawful search and seizure “ ‘are not proper matters to be presented by a motion to vacate sentence under § 2255 but can only be properly presented by appeal from the conviction.’ ” Id., at 220, quoting Warren v. United States, 311 F. 2d 673, 675 (CA8 1963).34 Though the precise discussion in Kaufman concerned the claims of federal prisoners under § 2255, the then-existing principle of a distinction between review of search-and-seizure claims in direct and collateral proceedings clearly existed.

There is no indication that Congress intended to wipe out this distinction. Indeed, the broad purpose of the 1966 amendments pointed in the opposite direction. The report of the Senate Judiciary Committee notes that:

“Although only a small number of these [habeas] applications have been found meritorious, the ap*273plications in their totality have imposed a heavy burden on the Federal courts. . . . The bill seeks to alleviate the unnecessary burden by introducing a greater degree of finality of judgments in habeas corpus proceedings.” S. Rep. No. 1797, 89th Cong., 2d Sess., 2 (1966).35

The House Report states similarly that:

“While in only a small number of these applications have the petitioners been successful, they nevertheless have not only imposed an unnecessary burden on the work of the Federal courts but have also greatly interfered with the procedures and processes of the State courts by delaying, in many cases, the proper enforcement of their judgments.” H. R. Rep. No. 1892, 89th Cong., 2d Sess., 5 (1966).

This most recent congressional expression on the scope of federal habeas corpus reflected the sentiment, shared alike by judges and legislators, that the writ has overrun its historical banks to inundate the dockets of federal courts and denigrate the role of state courts. Though Congress did not address the precise question at hand, nothing in §2254 (a), the state of the law at the time of its adoption, or the historical uses of the language “custody in violation of the Constitution” from which § 2254 (a) is derived,36 compels a holding that rulings of state courts on claims of unlawful search and *274seizure must be reviewed and redetermined in collateral proceedings.

YII

Perhaps no single development of the criminal law has had consequences so profound as the escalating use, over the past two decades, of federal habeas corpus to reopen and readjudicate state criminal judgments. I have commented in Part IV above on the far-reaching consequences: the burden on the system,37 in terms of demands on the courts, prosecutors, defense attorneys, and other personnel and facilities; the absence of efficiency and finality in the criminal process, frustrating both the deterrent function of the law and the effectiveness of rehabilitation ; the undue subordination of state courts, with the resulting exacerbation of state-federal relations; and the subtle erosion of the doctrine of federalism itself. Perhaps the single most disquieting consequence of open-ended habeas review is reflected in the prescience of Mr. Justice Jackson’s warning that “[i]t must prejudice the occasional meritorious application to be buried in a flood of worthless ones.” 38

If these consequences flowed from the safeguarding of constitutional claims of innocence they should, of course, be accepted as a tolerable price to pay for cherished standards of justice at the same time that efforts are pursued to find more rational procedures. Yet, as illustrated by the case before us today, the question on habeas corpus is *275too rarely whether the prisoner was innocent of the crime for which he was convicted39 and too frequently whether some evidence of undoubted probative value has been admitted in violation of an exclusionary rule ritualistically applied without due regard to whether it has the slightest likelihood of achieving its avowed prophylactic purpose.

It is this paradox of a system, which so often seems to subordinate substance to form, that increasingly provokes criticism and lack of confidence. Indeed, it is difficult to explain why a system of criminal justice deserves respect which allows repetitive reviews of convictions long since held to have been final at the end of the normal process of trial and appeal where the basis for re-examination is not even that the convicted defendant was innocent. There has been a halo about the “Great Writ” that no one would wish to dim. Yet one must wonder whether the stretching of its use far beyond any justifiable purpose will not in the end weaken rather than strengthen the writ’s vitality.

Me. Justice Douglas,

dissenting.

I agree with the Court of Appeals that “verbal assent” to a search is not enough, that the fact that consent was given to the search does not imply that the suspect knew that the alternative of a refusal existed. 448 F. 2d 699, 700. As that court stated:

“[U]nder many circumstances a reasonable person might read an officer's ‘May I’ as the courteous ex*276pression of a demand backed, by force of law.” Id., at 701.

A considerable constitutional guarantee rides on this narrow issue. At the time of the search there was no probable cause to believe that the car contained contraband or other unlawful articles. The car was stopped only because a headlight and the license plate light were burned out. The car belonged to Alcala’s brother, from whom it was borrowed, and Alcala had a driver’s license. Traffic citations were appropriately issued. The car was searched, the present record showing that Alcala consented. But whether Alcala knew he had the right to refuse, we do not know. All the Court of Appeals did was to remand the case to the District Court for a finding — and if necessary, a hearing on that issue.

I would let the case go forward on that basis. The long, time-consuming contest in this Court might well wash out. At least we could be assured that, if it came back, we would not be rendering an advisory opinion. Had I voted to grant this petition, I would suggest we dismiss it as improvidently granted. But, being in the minority, I am bound by the Rule of Four.

Mr. Justice Brennan,

dissenting.

The Fourth Amendment specifically guarantees “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures . . . .” We have consistently held that governmental searches conducted pursuant to a validly obtained warrant or reasonably incident to a valid arrest do not violate this guarantee. Here, however, as the Court itself recognizes, no search warrant was obtained and the State does not even suggest “that there was probable cause to search the vehicle or that the search was incident to a valid arrest of any of the occupants.” Ante, *277at 227-228. As a result, the search of the vehicle can be justified solely on the ground that the owner’s brother gave his consent — that is, that he waived his Fourth Amendment right “to be secure” against an otherwise “unreasonable” search. The Court holds today that an individual can effectively waive this right even though he is totally ignorant of the fact that, in the absence of his consent, such invasions of his privacy would be constitutionally prohibited. It wholly escapes me how our citizens can meaningfully be said to have waived something as precious as.a constitutional guarantee without ever being aware of its existence. In my view, the Court’s conclusion is supported neither by “linguistics,” nor by “epistemology,” nor, indeed, by “common sense.” I respectfully dissent.

Mr. Justice Marshall,

dissenting.

Several years ago, Mr. Justice Stewart reminded us that “[t]he Constitution guarantees ... a society of free choice. Such a society presupposes the capacity of its members to choose.” Ginsberg v. New York, 390 U. S. 629, 649 (1968) (concurring in result). I would have thought that the capacity to choose necessarily depends upon knowledge that there is a choice to be made. But today the Court reaches the curious result that one can choose to relinquish a constitutional right— the right to be free of unreasonable searches — without knowing that he has the alternative of refusing to accede to a police request to search.1 I cannot agree, and therefore dissent.

*278I

1 believe that the Court misstates the true issue in this case. That issue is not, as the Court suggests, whether the police overbore Alcala’s will in eliciting his consent, but rather, whether a simple statement of assent to search, without more,2 should be sufficient to permit the police to search and thus act as a relinquishment of Alcala’s constitutional right to exclude the police.3 This Court has always scrutinized with great care claims that a person has forgone the opportunity to assert constitutional rights. See, e. g., Fuentes v. Shevin, 407 U. S. 67 (1972); D. H. Overmyer Co. v. Frick Co., 405 U. S. 174 (1972); Boykin v. Alabama, 395 U. S. 238 (1969); Carnley v. Cochran, 369 U. S. 506 (1962). I see no reason to give the claim that a person consented to a search any less rigorous scrutiny. Every case in this Court involving this kind of search has heretofore spoken *279of consent as a waiver.4 See, e. g., Amos v. United States, 255 TJ. S. 313, 317 (1921); Zap v. United States, 328 U. S. 624, 628 (1946); Johnson v. United States, 333 U. S. 10, 13 (1948).5 Perhaps one skilled in lin*280guistics or epistemology can disregard those comments, but I find them hard to ignore.

To begin, it is important to understand that the opinion of the Court is misleading in its treatment of the issue here in three ways. First, it derives its criterion for determining when a verbal statement of assent to search operates as a relinquishment of a person’s right to preclude entry from a justification of consent searches that is inconsistent with our treatment in earlier cases of exceptions to the requirements of the Fourth Amendment, and that is not responsive to the unique nature of the consent-search exception. Second, it applies a standard of voluntariness that was developed in a very different context, where the standard was based on policies different from those involved in this case. Third, it mischaracterizes our prior cases involving consent searches.

A

The Court assumes that the issue in this case is: what are the standards by which courts are to determine that consent is voluntarily given? It then imports into the law of search and seizure standards developed to decide entirely different questions about coerced confessions.6

The Fifth Amendment, in terms, provides that no person “shall be compelled in any criminal case to be a witness against himself.” Nor is the interest protected by the Due Process Clause of the Fourteenth Amendment any different. The inquiry in a case where a confession is challenged as having been elicited in an unconstitutional manner is, therefore, whether the behavior *281of the police amounted to compulsion of the defendant.7 Because of the nature of the right to be free of compulsion, it would be pointless to ask whether a defendant knew of it before he made a statement; no sane person would knowingly relinquish a right to be free of compulsion. Thus, the questions of compulsion and of violation of the right itself are inextricably intertwined. The cases involving coerced confessions, therefore, pass over the question of knowledge of that right as irrelevant, and turn directly to the question of compulsion.

Miranda v. Arizona, 384 U. S. 436 (1966), confirms this analysis. There the Court held that certain warnings must be given to suspects prior to their interrogation so that the inherently coercive nature of in-custody questioning would be diminished by the suspect’s knowledge that he could remain silent. But, although those warnings, of course, convey information about various rights of the accused, the information is intended only to protect the suspect against acceding to the other coercive aspects of police interrogation. While we would not ordinarily think that a suspect could waive his right to be free of coercion, for example, we do permit suspects to waive the rights they are informed of by police warnings, on the belief that such information in itself sufficiently decreases the chance that a statement would be elicited by compulsion. Id., at 475-476. Thus, nothing the defendant did in the cases involving coerced confessions was taken to operate as a relinquishment of his rights; certainly the fact that the defendant made *282a statement was never taken to be a relinquishment of the right to be free of coercion.8

B

In contrast, this case deals not with “coercion,” but with “consent,” a subtly different concept to which different standards have been applied in the past. Freedom from coercion is a substantive right, guaranteed by the Fifth and Fourteenth Amendments. Consent, however, is a mechanism by which substantive requirements, otherwise applicable, are avoided. In the context of the Fourth Amendment, the relevant substantive requirements are that searches be conducted only after evidence justifying them has been submitted to an impartial magistrate for a determination of probable cause. There are, of course, exceptions to these requirements based on a variety of exigent circumstances that make it impractical to invalidate a search simply because the police failed to get a warrant.9 But none of the exceptions *283relating to the overriding needs of law enforcement are applicable when a search is justified solely by consent. On the contrary, the needs of law enforcement are significantly more attenuated, for probable cause to search may be lacking but a search permitted if the subject’s consent has been obtained. Thus, consent searches are permitted, not because such an exception to the requirements of probable cause and warrant is essential to proper law enforcement, but because we permit our citizens to choose whether or not they wish to exercise their constitutional rights. Our prior decisions simply do not support the view that a meaningful choice has been made solely because no coercion was brought to bear on the subject.

For example, in Bumper v. North Carolina, 391 U. S. 543 (1968), four law enforcement officers went to the home of Bumper’s grandmother. They announced that they had a search warrant, and she permitted them to enter. Subsequently, the prosecutor chose not to rely on the warrant, but attempted to justify the search by the woman’s consent. We held that consent could not be established “by showing no more than acquiescence to a claim of lawful authority,” id., at 548-549. We did not there inquire into all the circumstances, but focused on a single fact, the claim of authority, even though the grandmother testified that no threats were made. Id., at 547 n. 8. It may be that, on the facts of that case, her consent was under all the circumstances involuntary, but it is plain that we did not apply the test adopted by the Court today. And, whatever the posture of the case when it reached this Court, it could *284not be said that the police in Bumper acted in a threatening or coercive manner, for they did have the warrant they said they had; the decision not to rely on it was made long after the search, when the case came into court.10

That case makes it clear that police officers may not courteously order the subject of a search simply to stand aside while the officers carry out a search they have settled on. Yet there would be no coercion or brutality in giving that order. No interests that the Court today recognizes would be damaged in such a search. Thus, all the police must do is conduct what will inevitably be a charade of asking for consent. If they display any firmness at all, a verbal expression of assent will undoubtedly be forthcoming. I cannot believe that the protections of the Constitution mean so little.

II

My approach to the case is straightforward and, to me, obviously required by the notion of consent as a relinquishment of Fourth Amendment rights. I am at a loss to understand why consent “cannot be taken literally to mean a 'knowing’ choice.” Ante, at 224. In fact, I have difficulty in comprehending how a decision made without knowledge of available alternatives can be treated as a choice at all.

If consent to search means that a person has chosen to forgo his right to exclude the police from the place they seek to search, it follows that his consent cannot *285be considered a meaningful choice unless he knew that he could in fact exclude the police. The Court appears, however, to reject even the modest proposition that, if the subject of a search convinces the trier of fact that he did not know of his right to refuse assent to a police request for permission to search, the search must be held unconstitutional. For it says only that “knowledge of the right to refuse consent is one factor to be taken into account.” Ante, at 227. I find this incomprehensible. I can think of no other situation in which we would say that a person agreed to some course of action if he convinced us that he did not know that there was some other course he might have pursued. I would therefore hold, at a minimum, that the prosecution may not rely on a purported consent to search if the subject of the search did not know that he could refuse to give consent. That, I think, is the import of Bumper v. North Carolina, supra. Where the police claim authority to search yet in fact lack such authority, the subject does not know that he may permissibly refuse them entry, and it is this lack of knowledge that invalidates the consent.

If one accepts this view, the question then is a simple one: must the Government show that the subject knew of his rights, or must the subject show that he lacked such knowledge?

I think that any fair allocation of the burden would require that it be placed on the prosecution. On- this question, the Court indulges in what might be called the “straw man” method of adjudication. The Court responds to this suggestion by overinflating the burden. And, when it is suggested that the prosecution’s burden of proof could be easily satisfied if the police informed the subject of his rights, the Court responds by refusing to require the police to make a “detailed” inquiry. Ante, at 245. If the Court candidly faced the real *286question of allocating the burden of proof, neither of these maneuvers would be available to it.

If the burden is placed on the defendant, all the subject can do is to testify that he did not know of his rights. And I doubt that many trial judges will find for the defendant simply on the basis of that testimony. Precisely because the evidence is very hard to come by, courts have traditionally been reluctant to require a party to prove negatives such as the lack of knowledge. See, e. g., 9 J. Wigmore, Evidence 274 (3d ed. 1940); F. James, Civil Procedure § 7.8 (1965); E. Morgan, Some Problems of Proof Under the Anglo-American System of Litigation 75-76 (1956).

In contrast, there are several ways by which the subject’s knowledge of his rights may be shown. The subject may affirmatively demonstrate such knowledge by his responses at the time the search took place, as in United States v. Curíale, 414 F. 2d 744 (CA2 1969). Where, as in this case, the person giving consent is someone other than the defendant, the prosecution may require him to testify under oath. Denials of knowledge may be disproved by establishing that the subject had, in the recent past, demonstrated his knowledge of his rights, for example, by refusing entry when it was requested by the police. The prior experience or training of the subject might in some cases support an inference that he knew of his right to exclude the police.

The burden on the prosecutor would disappear, of course, if the police, at the time they requested consent to search, also told the subject that he had a right to refuse consent and that his decision to refuse would be respected. The Court’s assertions to the contrary notwithstanding, there is nothing impractical about this method of satisfying the prosecution’s burden of proof.11 *287It must be emphasized that the decision about informing the subject of his rights would lie with the officers seeking consent. If they believed that providing such information would impede their investigation, they might simply ask for consent, taking the risk that at some later date the prosecutor would be unable to prove that the subject knew of his rights or that some other basis for the search existed.

The Court contends that if an officer paused to inform the subject of his rights, the informality of the exchange would be destroyed. I doubt that a simple statement by an officer of an individual’s right to refuse consent would do much to alter the informality of the exchange, except to alert the subject to a fact that he surely is entitled to know. It is not without significance that for many years the agents of the Federal Bureau of Investigation have routinely informed subjects of their right to refuse consent, when they request consent to search. Note, Consent Searches: A Reappraisal After Miranda v. Arizona, 67 Col. L. Rev. 130, 143 n. 75 (1967) (citing letter from J. Edgar Hoover). The reported cases in which the police have informed subjects of their right to refuse consent show, also, that the information can be given without disrupting the casual flow of events. See, e. g., United States v. Miller, 395 F. 2d 116 (CA7 1968). What evidence there is, then, rather strongly suggests that nothing disastrous would happen if the police, before requesting consent, informed the subject that he had *288a right to refuse consent and that his refusal would be respected.12

I must conclude, with some reluctance, that when the Court speaks of practicality, what it really is talking of is the continued ability of the police to capitalize on the ignorance of citizens so as to accomplish by subterfuge what they could not achieve by relying only on the knowing relinquishment of constitutional rights. Of course it would be “practical” for the police to ignore the commands of the Fourth Amendment, if by practicality we mean that more criminals will be apprehended, even though the constitutional rights of innocent people also go by the board. But such a practical advantage is achieved only at the cost of permitting the police to disregard the limitations that the Constitution places on their behavior, a cost that a constitutional democracy cannot long absorb.

I find nothing in the opinion of the Court to dispel my belief that, in such a case, as the Court of Appeals for *289the Ninth Circuit said, “[u]nder many circumstances a reasonable person might read an officer’s ‘May I’ as the courteous expression of a demand backed by force of law.” 448 F. 2d, at 701. Most cases, in my view, are akin to Bumper v. North Carolina, 391 U. S. 543 (1968) : consent is ordinarily given as acquiescence in an implicit claim of authority to search. Permitting searches in such circumstances, without any assurance at all that the subject of the search knew that, by his consent, he was relinquishing his constitutional rights, is something that I cannot believe is sanctioned by the Constitution.

W-i I — H 1 — 1

The proper resolution of this case turns, I believe, on a realistic assessment of the nature of the interchange between citizens and the police, and of the practical import of allocating the burden of proof in one way rather than another. The Court seeks to escape such assessments by escalating its rhetoric to unwarranted heights, but no matter how forceful the adjectives the Court uses, it cannot avoid being judged by how well its image of these interchanges accords with reality. Although the Court says without real elaboration that it “cannot agree,” ante, at 248, the holding today confines the protection of the Fourth Amendment against searches conducted without probable cause to the sophisticated, the knowledgeable, and, I might add, the few.13 In the final analysis, the Court now sanctions a game of blindman’s buff, in which the police always have the upper hand, for the sake of nothing more than the convenience of *290the police. But the guarantees of the Fourth Amendment were never intended to shrink before such an ephemeral and changeable interest. The Framers of the Fourth Amendment struck the balance against this sort of convenience and in favor of certain basic civil rights. It is not for this Court to restrike that balance because of its own views of the needs of law enforcement officers. I fear that that is the effect of the Court's decision today.

It is regrettable that the obsession with validating searches like that conducted in this case, so evident in the Court’s hyperbole, has obscured the Court’s vision of how the Fourth Amendment was designed to govern the relationship between police and citizen in our society. I believe that experience and careful reflection show how narrow and inaccurate that vision is, and I respectfully dissent.

*179Justice Scalia delivered

the opinion of the Court.

In United States v. Matlock, 415 U. S. 164 (1974), this Court reaffirmed that a warrantless entry and search by law enforcement officers does not violate the Fourth Amendment’s proscription of “unreasonable searches and seizures” if the officers have obtained the consent of a third party who possesses common authority over the premises. The present case presents an issue we expressly reserved in Matlock, see id., at 177, n. 14: Whether a warrantless entry is valid when based upon the consent of a third party whom the police, at the time of the entry, reasonably believe to possess common authority over the premises, but who in fact does not do so.

I

Respondent Edward Rodriguez was arrested in his apartment by law. enforcement officers and charged with possession of illegal drugs. The police gained entry to the apartment with the consent and assistance of Gail Fischer, who had lived there with respondent for several months. The relevant facts leading to the arrest are as follows.

On July 26, 1985, police were summoned to the residence of Dorothy Jackson on South Wolcott in Chicago. They were met by Ms. Jackson’s daughter, Gail Fischer, who showed signs of a severe beating. She told the officers that she had been assaulted by respondent Edward Rodriguez earlier that day in an apartment on South California Avenue. Fischer stated that Rodriguez was then asleep in the apartment, and she consented to travel there with the police in order to unlock the door with her key so that the officers could enter and arrest him. During this conversation, Fischer several times referred to the apartment on South California as “our” apartment, and said that she had clothes and furniture there. It is unclear whether she indicated that she currently lived at the apartment, or only that she used to live there.

*180The police officers drove to the apartment on South California, accompanied by Fischer. They did not obtain an arrest warrant for Rodriguez, nor did they seek a search warrant for the apartment. At the apartment, Fischer unlocked the door with her key and gave the officers permission to enter. They moved through the door into the living room, where they observed in plain view drug paraphernalia and containers filled with white powder that they believed (correctly, as later analysis showed) to be cocaine. They proceeded to the bedroom, where they found Rodriguez asleep and discovered additional containers of white powder in two open attaché cases. The officers arrested Rodriguez and seized the drugs and related paraphernalia.

Rodriguez was charged with possession of a controlled substance with intent to deliver. He moved to suppress all evidence seized at the time of his arrest, claiming that Fischer had vacated the apartment several weeks earlier and had no authority to consent to the entry. The Cook County Circuit Court granted the motion, holding that at the time she consented to the entry Fischer did not have common authority over the apartment. The Court concluded that Fischer was not a “usual resident” but rather an “infrequent visitor” at the apartment on South California, based upon its findings that Fischer’s name was not on the lease, that she did not contribute to the rent, that she was not allowed to invite others to the apartment on her own, that she did not have access to the apartment when respondent was away, and that she had moved some of her possessions from the apartment. The Circuit Court also rejected the State’s contention that, even if Fischer did not possess common authority over the premises, there was no Fourth Amendment violation if the police reasonably believed at the time of their entry that Fischer possessed the authority to consent.

The Appellate Court of Illinois affirmed the Circuit Court in all respects. The Illinois Supreme Court denied the State’s petition for leave to appeal, 125 Ill. 2d 572, 537 *181N. E. 2d 816 (1989), and we granted certiorari. 493 U. S. 932 (1989).

II

The Fourth Amendment generally prohibits the warrant-less entry of a person’s home, whether to make an arrest or to search for specific objects. Payton v. New York, 445 U. S. 573 (1980); Johnson v. United States, 333 U. S. 10 (1948). The prohibition does not apply, however, to situations in which voluntary consent has been obtained, either from the individual whose property is searched, see Schneckloth v. Bustamonte, 412 U. S. 218 (1973), or from a third party who possesses common authority over the premises, see United States v. Matlock, supra, at 171. The State of Illinois contends that that exception applies in the present case.

As we stated in Matlock, supra, at 171, n. 7, “[cjommon authority” rests “on mutual use of the property by persons generally having joint access or control for most purposes . . . .” The burden of establishing that common authority rests upon the State. On the basis of this record, it is clear that burden was not sustained. The evidence showed that although Fischer, with her two small children, had lived with Rodriguez beginning in December 1984, she had moved out on July 1, 1985, almost a month before the search at issue here, and had gone to live with her mother. She took her and her children’s clothing with her, though leaving behind some furniture and household effects. During the period after July 1 she sometimes spent the night at Rodriguez’s apartment, but never invited her friends there, and never went there herself when he was not home. Her name was not on the lease nor did she contribute to the rent. She had a key to the apartment, which she said at trial she had taken without Rodriguez’s knowledge (though she testified at the preliminary hearing that Rodriguez had given her the key). On these facts the State has not established that, with respect to the South California apartment, Fischer had *182“joint access or control for most purposes.” To the contrary, the Appellate Court’s determination of no common authority over the apartment was obviously correct.

1 — l 1 — 1 1 — 1

A

The State contends that, even if Fischer did not in fact have authority to give consent, it suffices to validate the entry that the law enforcement officers reasonably believed she did. Before reaching the merits of that contention, we must consider a jurisdictional objection: that the decision below rests on an adequate and independent state ground. Respondent asserts that the Illinois Constitution provides greater protection than is afforded under the Fourth Amendment, and that the Appellate Court relied upon this when it determined that a reasonable belief by the police officers was insufficient.

When a state-court decision is clearly based on state law that is both adequate and independent, we will not review the decision. Michigan v. Long, 463 U. S. 1032, 1041 (1983). But when “a state court decision fairly appears to rest primarily on federal law, or to be interwoven with the federal law,” we require that it contain a “‘plain statement’ that [it] rests upon adequate and independent state grounds,” id., at 1040, 1042; otherwise, “we will accept as the most reasonable explanation that the state court decided the case the way it did because it believed that federal law required it to do so.” Id., at 1041. Here, the Appellate Court’s opinion contains no “plain statement” that its decision rests on state law. The opinion does not rely on (or even mention) any specific provision of the Illinois Constitution, nor even the Illinois Constitution generally. Even the Illinois cases cited by the opinion rely upon no constitutional provisions other than the Fourth and Fourteenth Amendments of the United States Constitution. We conclude that the Appellate Court of Illinois rested its decision on federal law.

*183B

On the merits of the issue, respondent asserts that permitting a reasonable belief of common authority to validate an entry would cause a defendant’s Fourth Amendment rights to be “vicariously waived.” Brief for Respondent 32. We disagree.

We have been unyielding in our insistence that a defendant’s waiver of his trial rights cannot be given effect unless it is “knowing” and “intelligent.” Colorado v. Spring, 479 U. S. 564, 574-575 (1987); Johnson v. Zerbst, 304 U. S. 458 (1938). We would assuredly not permit, therefore, evidence seized in violation of the Fourth Amendment to be introduced on the basis of a trial court’s mere “reasonable belief” — derived from statements by unauthorized persons — that the defendant has waived his objection. But one must make a distinction between, on the one hand, trial rights that derive from the violation of constitutional guarantees and, on the other hand, the nature of those constitutional guarantees themselves. As we said in Schneckloth:

“There is a vast difference between those rights that protect a fair criminal trial and the rights guaranteed under the Fourth Amendment. Nothing, either in the purposes behind requiring a ‘knowing’ and ‘intelligent’ waiver of trial rights, or in the practical application of such a requirement suggests that it ought to be extended to the constitutional guarantee against unreasonable searches and seizures.” 412 U. S., at 241.

What Rodriguez is assured by the trial right of the exclusionary rule, where it applies, is that no evidence seized in violation of the Fourth Amendment will be introduced at his trial unless he consents. What he is assured by the Fourth Amendment itself, however, is not that no government search of his house will occur unless he consents; but that no such search will occur that is “unreasonable." U. S. Const., Arndt. 4. There are various elements, of course, *184that can make a search of a person’s house “reasonable” — one of which is the consent of the person or his cotenant.. The essence of respondent’s argument is that we should impose upon this element a requirement that we have not imposed upon other elements that regularly compel government officers to exercise judgment regarding the facts: namely, the requirement that their judgment be not only responsible but correct.

The fundamental objective that alone validates all un-consented government searches is, of course, the seizure of persons who have committed or are about to commit crimes, or of evidence related to crimes. But “reasonableness,” with respect to this necessary element, does not demand that the government be factually correct in its assessment that that is what a search will produce. Warrants need only be supported by “probable cause,” which demands no more than a proper “assessment of probabilities in particular factual contexts . . . .” Illinois v. Gates, 462 U. S. 213, 232 (1983). If a magistrate, based upon seemingly reliable but factually inaccurate information, issues a warrant for the search of a house in which the sought-after felon is not present, has never been present, and was never likely to have been present, the owner of that house suffers one of the inconveniences we all expose ourselves to as the cost of living in a safe society; he does not suffer a violation of the Fourth Amendment.

Another element often, though not invariably, required in order to render an unconsented search “reasonable” is, of course, that the officer be authorized by a valid warrant. Here also we have not held that “reasonableness” precludes error with respect to those factual judgments that law enforcement officials are expected to make. In Maryland v. Garrison, 480 U. S. 79 (1987), a warrant supported by probable cause with respect to one apartment was erroneously issued for an entire floor that was divided (though not clearly) into two apartments. We upheld the search of the apartment not properly covered by the warrant. We said:

*185“[T]he validity of the search of respondent’s apartment pursuant to a warrant authorizing the search of the entire third floor depends on whether the officers’ failure to realize the overbreadth of the warrant was objectively understandable and reasonable. Here it unquestionably was. The objective facts available to the officers at the time suggested no distinction between [the suspect’s] apartment and the third-floor premises.” Id., at 88.

The ordinary requirement of a warrant is sometimes supplanted by other elements that render the unconsented search “reasonable.” Here also we have not held that the Fourth Amendment requires factual accuracy. A warrant is not needed, for example, where the search is incident to an arrest. In Hill v. California, 401 U. S. 797 (1971), we upheld a search incident to an arrest, even though the arrest was made of the wrong person. We said:

“The upshot was that the officers in good faith believed Miller was Hill and arrested him. They were quite wrong as it turned out, and subjective good-faith belief would not in itself justify either the arrest or the subsequent search. But sufficient probability, not certainty, is the touchstone of reasonableness under the Fourth Amendment and on the record before us the officers’ mistake was understandable and the arrest a reasonable response to the situation facing them at the time.” Id., at 803-804.

It would be superfluous to multiply these examples. It is apparent that in order to satisfy the “reasonableness” requirement of the Fourth Amendment, what is generally demanded of the many factual determinations that must regularly be made by agents of the government — whether the magistrate issuing a warrant, the police officer executing a warrant, or the police officer conducting a search or seizure under one of the exceptions to the warrant requirement — is not that they always be correct, but that they always be rea*186sonable. As we put it in Brinegar v. United States, 338 U. S. 160, 176 (1949):

“Because many situations which confront officers in the course of executing their duties are more or less ambiguous, room must be allowed for some mistakes on their part. But the mistakes must be those of reasonable men, acting on facts leading sensibly to their conclusions of probability.”

We see no reason to depart from this general rule with respect to facts bearing upon the authority to consent to a search. Whether the basis for such authority exists is the sort of recurring factual question to which law enforcement officials must be expected to apply their judgment; and all the Fourth Amendment requires is that they answer it reasonably. The Constitution is no more violated when officers enter without a warrant because they reasonably (though erroneously) believe that the person who has consented to their entry is a resident of the premises, than it is violated when they enter without a warrant because they reasonably (though erroneously) believe they are in pursuit of a violent felon who is about to escape. See Archibald v. Mosel, 677 F. 2d 5 (CA1 1982).*

*187 Stoner v. California, 376 U. S. 483 (1964), is in our view not to the contrary. There, in holding that police had improperly entered the defendant’s hotel room based on the consent of a hotel clerk, we stated that “the rights protected by the Fourth Amendment are not to be eroded ... by unrealistic doctrines of ‘apparent authority.’” Id., at 488. It is ambiguous, of course, whether the word “unrealistic” is descriptive or limiting — that is, whether we were condemning as unrealistic all reliance upon apparent authority, or whether we were condemning only such reliance upon apparent authority as is unrealistic. Similarly ambiguous is the opinion’s earlier statement that “there [is no] substance to the claim that the search was reasonable because the police, relying upon the night clerk’s expressions of consent, had a reasonable basis for the belief that the clerk had authority to consent to the search.” Ibid. Was there no substance to it because it failed as a matter of law, or because the facts could not possibly support it? At one point the opinion does seem to speak clearly:

“It is important to bear in mind that it was the petitioner’s constitutional right which was at stake here, and not the night clerk’s nor the hotel’s. It was a right, therefore, which only the petitioner could waive by word or deed, either directly or through an agent.” Id., at 489.

But as we have discussed, what is at issue when a claim of apparent consent is raised is not whether the right to be free of searches has been waived, but whether the right to be free of unreasonable searches has been violated. Even if one does not think the Stoner opinion had this subtlety in mind, the supposed clarity of its foregoing statement is immediately compromised, as follows:

*188“It is true that the night clerk clearly and unambiguously consented to the search. But there is nothing in the record to indicate that the police had any basis whatsoever to believe that the night clerk had been authorized by the petitioner to permit the police to search the petitioner’s room.” Ibid, (emphasis added).

The italicized language should have been deleted, of course, if the statement two sentences earlier meant that an appearance of authority could never validate a search. In the last analysis, one must admit that the rationale of Stoner was ambiguous — and perhaps deliberately so. It is at least a reasonable reading of the case, and perhaps a preferable one, that the police could not rely upon the obtained consent because they knew it came from a hotel clerk, knew that the room was rented and exclusively occupied by the defendant, and could not reasonably have believed that the former had general access to or control over the latter. Similarly ambiguous in its implications (the Court’s opinion does not even allude to, much less discuss the effects of, “reasonable belief”) is Chapman v. United States, 365 U. S. 610 (1961). In sum, we were correct in Matlock, 415 U. S., at 177, n. 14, when we regarded the present issue as unresolved.

As Stoner demonstrates, what we hold today does not suggest that law enforcement officers may always accept a person’s invitation to enter premises. Even when the invitation is accompanied by an explicit assertion that the person lives there, the surrounding circumstances could conceivably be such that a reasonable person would doubt its truth and not act upon it without further inquiry. As with other factual determinations bearing upon search and seizure, determination of consent to enter must “be judged against an objective standard: would the facts available to the officer at the moment . . . ‘warrant a man of reasonable caution in the belief’ ” that the consenting party had authority over the premises? Terry v. Ohio, 392 U. S. 1, 21-22 (1968). If not, then war-*189rantless entry without further inquiry is unlawful unless authority actually exists. But if so, the search is valid.

* * *

In the present case, the Appellate Court found it unnecessary to determine whether the officers reasonably believed that Fischer had the authority to consent, because it ruled as a matter of law that a reasonable belief could not validate the entry. Since we find that ruling to be in error, we remand for consideration of that question. The judgment of the Illinois Appellate Court is reversed, and the case is remanded for further proceedings not inconsistent with this opinion.

So ordered.

Justice Marshall,

with whom Justice Brennan and Justice Stevens join, dissenting.

Dorothy Jackson summoned police officers to her house to report that her daughter Gail Fischer had been beaten. Fischer told police that Ed Rodriguez, her boyfriend, was her assaulter. During an interview with Fischer, one of the officers asked if Rodriguez dealt in narcotics. Fischer did not respond. Fischer did agree, however, to the officers’ request to let them into Rodriguez’s apartment so that they could arrest him for battery. The police, without a warrant and despite the absence of an exigency, entered Rodriguez’s home to arrest him. As a result of their entry, the police discovered narcotics that the State subsequently sought to introduce in a drug prosecution against Rodriguez.

The majority agrees with the Illinois Appellate Court’s determination that Fischer did not have authority to consent to the officers’ entry of Rodriguez’s apartment. Ante, at 181-182. The Court holds that the warrantless entry into Rodriguez’s home was nonetheless valid if the officers reasonably believed that Fischer had authority to consent. Ante this page. The majority’s defense of this position rests on a misconception of the basis for third-party consent searches. That *190such searches do not give rise to claims of constitutional violations rests not on the premise that they are “reasonable” under the Fourth Amendment, see ante, at 183-184, but on the premise that a person may voluntarily limit his expectation of privacy by allowing others to exercise authority over his possessions. Cf. Katz v. United States, 389 U. S. 347, 351 (1967) (“What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection”). Thus, an individual’s decision to permit another “joint access [to] or control [over the property] for most purposes,” United States v. Matlock, 415 U. S. 164, 171, n. 7 (1974), limits that individual’s reasonable expectation of privacy and to that extent limits his Fourth Amendment protections. Cf. Rakas v. Rlinois, 439 U. S. 128, 148 (1978) (because passenger in car lacked “legitimate expectation of privacy in the glove compartment,” Court did not decide whether search would violate Fourth Amendment rights of someone who had such expectation). If an individual has not so limited his expectation of privacy, the police may not dispense with the safeguards established by the Fourth Amendment.

The baseline for the reasonableness of a search or seizure in the home is the presence of a warrant. Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602 (1989). Indeed, “searches and seizures inside a home without a warrant are presumptively unreasonable.” Payton v. New York, 445 U. S. 573, 586 (1980). Exceptions to the warrant requirement must therefore serve “compelling” law enforcement goals. Mincey v. Arizona, 437 U. S. 385, 394 (1978). Because the sole law enforcement purpose underlying third-party consent searches is avoiding the inconvenience of securing a warrant, a departure from the warrant requirement is not justified simply because an officer reasonably believes a third party has consented to a search of the defendant’s home. In holding otherwise, the majority ignores our longstanding view that “the informed and deliberate determina*191tions of magistrates ... as to what searches and seizures are permissible under the Constitution are to be preferred over the hurried action of officers and others who may happen to make arrests.” United States v. Lefkowitz, 285 U. S. 452, 464 (1932).

I

The Fourth Amendment provides that “[t]he right of the people to be secure in their . . . houses . . . shall not be violated.” We have recognized 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, Eastern District of Michigan, 407 U. S. 297, 313 (1972). We have further held that “a search or seizure carried out on a suspect’s premises without a warrant is per se unreasonable, unless the police can show that it falls within one of a carefully defined set of exceptions.” Coolidge v. New Hampshire, 403 U. S. 443, 474 (1971). Those exceptions must be crafted in light of the warrant requirement’s purposes. As this Court stated in McDonald v. United States, 335 U. S. 451 (1948):

“The presence of a search warrant serves a high function. Absent some grave emergency, the Fourth Amendment has interposed a magistrate between the citizen and the police. This was done not to shield criminals nor to make the home a safe haven for illegal activities. It was done so that an objective mind might weigh the need to invade that privacy in order to enforce the law. The right of privacy was deemed too precious to entrust to the discretion of those whose job is the detection of crime and the arrest of criminals.” Id., at 455-456.

The Court has tolerated departures from the warrant requirement only when an exigency makes a warrantless search imperative to the safety of the police and of the community. See, e. g., id., at 456 (“We cannot be true to that *192constitutional requirement and excuse the absence of a search warrant without a showing by those who seek exemption from the constitutional mandate that the exigencies of the situation made that course imperative”); Warden v. Hayden, 387 U. S. 294 (1967) (hot pursuit); Chimel v. California, 395 U. S. 752 (1969) (interest in officers’ safety justifies search incident to an arrest); Michigan v. Tyler, 436 U. S. 499, 509 (1978) (“compelling need for official action and no time to secure a warrant” justifies warrantless entry of burning building). The Court has often heard, and steadfastly rejected, the invitation to carve out further exceptions to the warrant requirement for searches of the home because of the burdens on police investigation and prosecution of crime. Our rejection of such claims is not due to a lack of appreciation of the difficulty and importance of effective law enforcement, but rather to our firm commitment to “the view of those who wrote the Bill of Rights that the privacy of a person’s home and property may not be totally sacrificed in the name of maximum simplicity in enforcement of the criminal law.” Mincey, supra, at 393 (citing United States v. Chadwick, 433 U. S. 1, 6-11 (1977)).

In the absence of an exigency, then, warrantless home searches and seizures are unreasonable under the Fourth Amendment. The weighty constitutional interest in preventing unauthorized intrusions into the home overrides any law enforcement interest in relying on the reasonable but potentially mistaken belief that a third party has authority to consent to such a search or seizure. Indeed, as the present case illustrates, only the minimal interest in avoiding the inconvenience of obtaining a warrant weighs in on the law enforcement side.

Against this law enforcement interest in expediting arrests is “the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.” Silverman v. United States, 365 U. S. 505, 511 (1961). To be sure, in some cases in which police officers reasonably rely on a *193third party’s consent, the consent will prove valid, no intrusion will result, and the police will have been spared the inconvenience of securing a warrant. But in other cases, such as this one, the authority claimed by the third party will be false. The reasonableness of police conduct must be measured in light of the possibility that the target has not consented. Where “[n]o reason is offered for not obtaining a search warrant except the inconvenience to the officers and some slight delay necessary to prepare papers and present the evidence to a magistrate,” the Constitution demands that the warrant procedure be observed. Johnson v. United States, 333 U. S. 10, 15 (1948). The concerns of expediting police work and avoiding paperwork “are never very convincing reasons and, in these circumstances, certainly are not enough to by-pass the constitutional requirement.” Ibid. In this case, as in Johnson, “[n]o suspect was fleeing or likely to take flight. The search was of permanent premises, not of a movable vehicle. No evidence or contraband was threatened with removal or destruction .... If the officers in this case were excused from the constitutional duty of presenting their evidence to a magistrate, it is difficult to think of a case in which it should be required.” Ibid.

Unlike searches conducted pursuant to the recognized exceptions to the warrant requirement, see supra, at 191-192, third-party consent searches are not based on an exigency and therefore serve no compelling social goal. Police officers, when faced with the choice of relying on consent by a third party or securing a warrant, should secure a warrant and must therefore accept the risk of error should they instead choose to rely on consent.

II

Our prior cases discussing searches based on third-party consent have never suggested that such searches are “reasonable.” In United States v. Matlock, this Court upheld a warrantless search conducted pursuant to the consent of a *194third party who was living with the defendant. The Court rejected the defendant’s challenge to the search, stating that a person who permits others to have “joint access or control for most purposes . . . assume[s] the risk that [such persons] might permit the common area to be searched.” 415 U. S., at 171, n. 7; see also Frazier v. Cupp, 394 U. S. 731, 740 (1969) (holding that defendant who left a duffel bag at another’s house and allowed joint use of the bag “assumed the risk that [the person] would allow someone else to look inside”). As the Court’s assumption-of-risk analysis makes clear, third-party consent limits a person’s ability to challenge the reasonableness of the search only because that person voluntarily has relinquished some of his expectation of privacy by sharing access or control over his property with another person.

A search conducted pursuant to an officer’s reasonable but mistaken belief that a third party had authority to consent is thus on an entirely different constitutional footing from one based on the consent of a third party who in fact has such authority. Even if the officers reasonably believed that Fischer had authority to consent, she did not, and Rodriguez’s expectation of privacy was therefore undiminished. Rodriguez accordingly can challenge the warrantless intrusion into his home as a violation of the Fourth Amendment. This conclusion flows directly from Stoner v. California, 376 U. S. 483 (1964). There, the Court required the suppression of evidence seized in reliance on a hotel clerk’s consent to a war-rantless search of a guest’s room. The Court reasoned that the guest’s right to be free of unwarranted intrusion “was a right. . . which only [he] could waive by word or deed, either directly or through an agent.” Id., at 489. Accordingly, the Court rejected resort to “unrealistic doctrines of ‘apparent authority’ ” as a means of upholding the search to which the guest had not consented. Id., at 488.1

*195III

Acknowledging that the third party in this case lacked authority to consent, the majority seeks to rely on cases suggesting that reasonable but mistaken factual judgments by police will not invalidate otherwise reasonable searches. The majority reads these cases as establishing a “general rule” that “what is generally demanded of the many factual determinations that must regularly be made by agents of the government — whether the magistrate issuing a warrant, the police officer executing a warrant, or the police officer conducting a search or seizure under one of the exceptions to the *196warrant requirement — is not that they always be correct, but that they always be reasonable.” Ante, at 185-186.

The majority’s assertion, however, is premised on the erroneous assumption that third-party consent searches are generally reasonable. The cases the majority cites thus provide no support for its holding. In Brinegar v. United States, 338 U. S. 160 (1949), for example, the Court confirmed the unremarkable proposition that police need only probable cause, not absolute certainty, to justify the arrest of a suspect on a highway. As Brinegar makes clear, the possibility of factual error is built into the probable cause standard, and such a standard, by its very definition, will in some cases result in the arrest of a suspect who has not actually committed a crime. Because probable cause defines the reasonableness of searches and seizures outside of the home, a search is reasonable under the Fourth Amendment whenever that standard is met, notwithstanding the possibility of “mistakes” on the part of police. Id., at 176. In contrast, our cases have already struck the balance against warrantless home intrusions in the absence of an exigency. See supra, at 191-192. Because reasonable factual errors by law enforcement officers will not validate unreasonable searches, the reasonableness of the officer’s mistaken belief that the third party had authority to consent is irrelevant.2

*197The majority’s reliance on Maryland v. Garrison, 480 U. S. 79 (1987), is also misplaced. In Garrison, the police obtained a valid warrant for the search of the “third floor apartment” of a building whose third floor in fact housed two apartments. Id., at 80. Although the police had probable cause to search only one of the apartments, they entered both apartments because “[t]he objective facts available to the officers at the time suggested no distinction between [the apartment for which they legitimately had the warrant and the entire third floor].” Id., at 88. The Court held that the officers’ reasonable mistake of fact did not render the search unconstitutional. Id., at 88-89. As in Brinegar, the Court’s decision was premised on the general reasonableness of the type of police action involved. Because searches based on warrants are generally reasonable, the officers’ reasonable mistake of fact did not render their search “unreasonable.” This reasoning is evident in the Court’s conclusion that little would be gained by adopting additional burdens “over and above the bedrock requirement that, with the exceptions we have traced in our cases, the police may conduct searches only pursuant to a reasonably detailed warrant.” Garrison, supra, at 89, n. 14.

Garrison, like Brinegar, thus tells us nothing about the reasonableness under the Fourth Amendment of a warrant-less arrest in the home based on an officer’s reasonable but mistaken belief that the third party consenting to the arrest was empowered to do so. The majority’s glib assertion that “[i]t would be superfluous to multiply” its citations to cases like Brinegar, Hill, and Garrison, ante, at 185, is thus correct, but for a reason entirely different than the majority suggests. Those cases provide no illumination of the issue raised in this case, and further citation to like cases would be *198as superfluous as the discussion on which the majority’s conclusion presently depends.

IV

Our cases demonstrate that third-party consent searches are free from constitutional challenge only to the extent that they rest on consent by a party empowered to do so. The majority’s conclusion to the contrary ignores the legitimate expectations of privacy on which individuals are entitled to rely. That a person who allows another joint access to his property thereby limits his expectation of privacy does not justify trampling the rights of a person who has not similarly relinquished any of his privacy expectation.

Instead of judging the validity of consent searches, as we have in the past, based on whether a defendant has in fact limited his expectation of privacy, the Court today carves out an additional exception to the warrant requirement for third-party consent searches without pausing to consider whether “ ‘the exigencies of the situation’ make the needs of law enforcement so compelling that the warrantless search is objectively reasonable under the Fourth Amendment,” Mincey, 437 U. S., at 394 (citations omitted). Where this free-floating creation of “reasonable” exceptions to the warrant requirement will end, now that the Court has departed from the balancing approach that has long been part of our Fourth Amendment jurisprudence, is unclear. But by allowing a person to be subjected to a warrantless search in his home without his consent and without exigency, the majority has taken away some of the liberty that the Fourth Amendment was designed to protect.

*106Justice Souter

delivered the opinion of the Court.

The Fourth Amendment recognizes a valid warrantless entry and search of premises when police obtain the voluntary consent of an occupant who shares, or is reasonably believed to share, authority over the area in common with a co-occupant who later objects to the use of evidence so obtained. Illinois v. Rodriguez, 497 U. S. 177 (1990); United States v. Matlock, 415 U. S. 164 (1974). The question here is whether such an evidentiary seizure is likewise lawful with the permission of one occupant when the other, who later seeks to suppress the evidence, is present at the scene and expressly refuses to consent. We hold that, in the circumstances here at issue, a physically present co-occupant’s stated refusal to permit entry prevails, rendering the warrantless search unreasonable and invalid as to him.

I

Respondent Scott Randolph and his wife, Janet, separated in late May 2001, when she left the marital residence in Americus, Georgia, and went to stay with her parents in Canada, taking their son and some belongings. In July, she returned to the Americus house with the child, though the record does not reveal whether her object was reconciliation or retrieval of remaining possessions.

*107On the morning of July 6, she complained to the police that after a domestic dispute her husband took their son away, and when officers reached the house she told them that her husband was a cocaine user whose habit had caused financial troubles. She mentioned the marital problems, and said that she and their son had only recently returned after a stay of several weeks with her parents. Shortly after the police arrived, Scott Randolph returned and explained that he had removed the child to a neighbor’s house out of concern that his wife might take the boy out of the country again; he denied cocaine use, and countered that it was in fact his wife who abused drugs and alcohol.

One of the officers, Sergeant Murray, went with Janet Randolph to reclaim the child, and when they returned she not only renewed her complaints about her husband’s drug use, but also volunteered that there were “‘items of drug evidence’ ” in the house. Brief for Petitioner 3. Sergeant Murray asked Scott Randolph for permission to search the house, which he unequivocally refused.

The sergeant turned to Janet Randolph for consent to search, which she readily gave. She led the officer upstairs to a bedroom that she identified as Scott’s, where the sergeant noticed a section of a drinking straw with a powdery residue he suspected was cocaine. He then left the house to get an evidence bag from his car and to call the district attorney’s office, which instructed him to stop the search and apply for a warrant. When Sergeant Murray returned to the house, Janet Randolph withdrew her consent. The police took the straw to the police station, along with the Randolphs. After getting a search warrant, they returned to the house and seized further evidence of drug use, on the basis of which Scott Randolph was indicted for possession of cocaine.

He moved to suppress the evidence, as products of a warrantless search of his house unauthorized by his wife’s consent over his express refusal. The trial court denied the *108motion, ruling that Janet Randolph had common authority to consent to the search.

The Court of Appeals of Georgia reversed, 264 Ga. App. 396, 590 S. E. 2d 834 (2003), and was itself sustained by the State Supreme Court, principally on the ground that “the consent to conduct a warrantless search of a residence given by one occupant is not valid in the face of the refusal of another occupant who is physically present at the scene to permit a warrantless search,” 278 Ga. 614, 604 S. E. 2d 835, 836 (2004). The Supreme Court of Georgia acknowledged this Court’s holding in Matlock, 415 U. S. 164, that “the consent of one who possesses common authority over premises or effects is valid as against the absent, nonconsenting person with whom that authority is shared,” id., at 170, and found Matlock distinguishable just because Scott Randolph was not “absent” from the colloquy on which the police relied for consent to make the search. The State Supreme Court stressed that the officers in Matlock had not been “faced with the physical presence of joint occupants, with one consenting to the search and the other objecting.” 278 Ga., at 615, 604 S. E. 2d, at 837. It held that an individual who chooses to live with another assumes a risk no greater than “ 'an inability to control access to the premises during [his] absence,’” ibid, (quoting 3 W. LaFave, Search and Seizure § 8.3(d), p. 731 (3d ed. 1996) (hereinafter LaFave)), and does not contemplate that his objection to a request to search commonly shared premises, if made, will be overlooked.

We granted certiorari to resolve a split of authority on whether one occupant may give law enforcement effective consent to search shared premises, as against a co-tenant who is present and states a refusal to permit the search.1 544 U. S. 973 (2005). We now affirm.

*109II

To the Fourth Amendment rule ordinarily prohibiting the warrantless entry of a person’s house as unreasonable per se, Payton v. New York, 445 U. S. 573, 586 (1980); Coolidge v. New Hampshire, 403 U. S. 443, 454-455 (1971), one “jealously and carefully drawn” exception, Jones v. United States, 357 U. S. 493, 499 (1958), recognizes the validity of searches with the voluntary consent of an individual possessing authority, Rodriguez, 497 U. S., at 181. That person might be the householder against whom evidence is sought, Schneckloth v. Bustamonte, 412 U. S. 218, 222 (1973), or a fellow occupant who shares common authority over property, when the suspect is absent, Matlock, supra, at 170, and the exception for consent extends even to entries and searches with the permission of a co-occupant whom the police reasonably, but erroneously, believe to possess shared authority as an occupant, Rodriguez, supra, at 186. None of our co-occupant consent-to-search cases, however, has presented the further fact of a second occupant physically present and refusing permission to search, and later moving to suppress evidence so obtained.2 The significance of such a refusal turns on the underpinnings of the co-occupant consent rule, as recognized since Matlock.

A

The defendant in that case was arrested in the yard of a house where he lived with a Mrs. Graff and several of her *110relatives, and was detained in a squad ear parked nearby. When the police went to the door, Mrs. Graff admitted them and consented to a search of the house. 415 U. S., at 166. In resolving the defendant’s objection to use of the evidence taken in the warrantless search, we said that “the consent of one who possesses common authority over premises or effects is valid as against the absent, nonconsenting person with whom that authority is shared.” Id., at 170. Consistent with our prior understanding that Fourth Amendment rights are not limited by the law of property, cf. Katz v. United States, 389 U. S. 347, 352-353 (1967), we explained that the third party’s “common authority” is not synonymous with a technical property interest:

“The authority which justifies the third-party consent does not rest upon the law of property, with its attendant historical and legal refinements, but rests rather on mutual use of the property by persons generally having joint access or control for most purposes, so that it is reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right and that the others have assumed the risk that one of their number might permit the common area to be searched.” 415 U. S., at 171, n. 7 (citations omitted).

See also Frazier v. Cupp, 394 U. S. 731, 740 (1969) (“[I]n allowing [his cousin to share use of a duffel bag] and in leaving it in his house, [the suspect] must be taken to have assumed the risk that [the cousin] would allow someone else to look inside”). The common authority that counts under the Fourth Amendment may thus be broader than the rights accorded by property law, see Rodriguez, supra, at 181-182 (consent is sufficient when given by a person who reasonably appears to have common authority but who, in fact, has no property interest in the premises searched), although its limits, too, reflect specialized tenancy arrangements apparent to the police, see Chapman v. United States, 365 U. S. *111610 (1961) (landlord could not consent to search of tenant’s home).

The constant element in assessing Fourth Amendment reasonableness in the consent cases, then, is the great significance given to widely shared social expectations, which are naturally enough influenced by the law of property, but not controlled by its rules. Cf. Rakas v. Illinois, 439 U. S. 128, 144, n. 12 (1978) (an expectation of privacy is reasonable if it has “a source outside of the Fourth Amendment, either by reference to concepts of real or personal property law or to understandings that are recognized and permitted by society”). Matlock accordingly not only holds that a solitary co-inhabitant may sometimes consent to a search of shared premises, but stands for the proposition that the reasonableness of such a search is in significant part a function of commonly held understanding about the authority that co-inhabitants may exercise in ways that affect each other’s interests.

B

Matlock’s example of common understanding is readily apparent. When someone comes to the door of a domestic dwelling with a baby at her hip, as Mrs. Graff did, she shows that she belongs there, and that fact standing alone is enough to tell a law enforcement officer or any other visitor that if she occupies the place along with others, she probably lives there subject to the assumption tenants usually make about their common authority when they share quarters. They understand that any one of them may admit visitors, with the consequence that a guest obnoxious to one may nevertheless be admitted in his absence by another. As Matlock put it, shared tenancy is understood to include an “assumption of risk,” on which police officers are entitled to rely, and although some group living together might make an exceptional arrangement that no one could admit a guest without the agreement of all, the chance of such an eccentric scheme is too remote to expect visitors to investigate a particular *112household’s rules before accepting an invitation to come in. So, Matlock relied on what was usual and placed no burden on the police to eliminate the possibility of atypical arrangements, in the absence of reason to doubt that the regular scheme was in place.

It is also easy to imagine different facts on which, if known, no common authority could sensibly be suspected. A person on the scene who identifies himself, say, as a landlord or a hotel manager calls up no customary understanding of authority to admit guests without the consent of the current occupant. See Chapman v. United States, supra (landlord); Stoner v. California, 376 U. S. 483 (1964) (hotel manager). A tenant in the ordinary course does not take rented premises subject to any formal or informal agreement that the landlord may let visitors into the dwelling, Chapman, supra, at 617, and a hotel guest customarily has no reason to expect the manager to allow anyone but his own employees into his room, see Stoner, supra, at 489; see also United States v. Jeffers, 342 U. S. 48, 51 (1951) (hotel staff had access to room for purposes of cleaning and maintenance, but no authority to admit police). In these circumstances, neither state-law property rights, nor common contractual arrangements, nor any other source points to a common understanding of authority to admit third parties generally without the consent of a person occupying the premises. And when it comes to searching through bureau drawers, there will be instances in which even a person clearly belonging on premises as an occupant may lack any perceived authority to consent; “a child of eight might well be considered to have the power to consent to the police crossing the threshold into that part of the house where any caller, such as a pollster or salesman, might well be admitted,” 4 LaFave § 8.4(c), at 207 (4th ed. 2004), but no one would reasonably expect such a child to be in a position to authorize anyone to rummage through his parents’ bedroom.

*113c

Although we have not dealt directly with the reasonableness of police entry in reliance on consent by one occupant subject to immediate challenge by another, we took a step toward the issue in an earlier case dealing with the Fourth Amendment rights of a social guest arrested at premises the police entered without a warrant or the benefit of any exception to the warrant requirement. Minnesota v. Olson, 495 U. S. 91 (1990), held that overnight houseguests have a legitimate expectation of privacy in their temporary quarters because “it is unlikely that [the host] will admit someone who wants to see or meet with the guest over the objection of the guest,” id., at 99. If that customary expectation of courtesy or deference is a foundation of Fourth Amendment rights of a houseguest, it presumably should follow that an inhabitant of shared premises may claim at least as much, and it turns out that the co-inhabitant naturally has an even stronger claim.

To begin with, it is fair to say that a caller standing at the door of shared premises would have no confidence that one occupant’s invitation was a sufficiently good reason to enter when a fellow tenant stood there saying, “stay out.” Without some very good reason, no sensible person would go inside under those conditions. Fear for the safety of the occupant issuing the invitation, or of someone else inside, would be thought to justify entry, but the justification then would be the personal risk, the threats to life or limb, not the disputed invitation.3

The visitor’s reticence without some such good reason would show not timidity but a realization that when people living together disagree over the use of their common quar*114ters, a resolution must come through voluntary accommodation , not by appeals to authority. Unless the people living together fall within some recognized hierarchy, like a household of parent and child or barracks housing military personnel of different grades, there is no societal understanding of superior and inferior, a fact reflected in a standard formulation of domestic property law, that “[e]ach cotenant . . . has the right to use and enjoy the entire property as if he or she were the sole owner, limited only by the same right in the other cotenants.” 7 R. Powell, Powell on Real Property § 50.03[1], p. 50-14 (M. Wolf gen. ed. 2005). The want of any recognized superior authority among disagreeing tenants is also reflected in the law’s response when the disagreements cannot be resolved. The law does not ask who has the better side of the conflict; it simply provides a right to any co-tenant, even the most unreasonable, to obtain a decree partitioning the property (when the relationship is one of co-ownership) and terminating the relationship. See, e. g., 2 H. Tiffany, Real Property §§468, 473, 474, pp. 297, 307-309 (3d ed. 1939 and 2006 Cum. Supp.). And while a decree of partition is not the answer to disagreement among rental tenants, this situation resembles co-ownership in lacking the benefit of any understanding that one or the other rental co-tenant has a superior claim to control the use of the quarters they occupy together. In sum, there is no common understanding that one co-tenant generally has a right or authority to prevail over the express wishes of another, whether the issue is the color of the curtains or invitations to outsiders.

D

Since the co-tenant wishing to open the door to a third party has no recognized authority in law or social practice to prevail over a present and objecting co-tenant, his disputed invitation, without more, gives a police officer no better claim to reasonableness in entering than the officer would have in the absence of any consent at all. Accordingly, in the bal*115ancing of competing individual and governmental interests entailed by the bar to unreasonable searches, Camara v. Municipal Court of City and County of San Francisco, 387 U. S. 523, 536-537 (1967), the cooperative occupant’s invitation adds nothing to the government’s side to counter the force of an objecting individual’s claim to security against the government’s intrusion into his dwelling place. Since we hold to the “centuries-old principle of respect for the privacy of the home,” Wilson v. Layne, 526 U. S. 603, 610 (1999), “it is beyond dispute that the home is entitled to special protection as the center of the private lives of our people,” Minnesota v. Carter, 525 U. S. 83, 99 (1998) (Kennedy, J., concurring). We have, after all, lived our whole national history with an understanding of “the ancient adage that a man’s house is his castle [to the point that t]he poorest man may in his cottage bid defiance to all the forces of the Crown,” Miller v. United States, 357 U. S. 301, 307 (1958) (internal quotation marks omitted).4

Disputed permission is thus no match for this central value of the Fourth Amendment, and the State’s other countervailing claims do not add up to outweigh it.5 Yes, we recognize the consenting tenant’s interest as a citizen in bringing crim*116inal activity to light, see Coolidge, 403 U. S., at 488 (“[I]t is no part of the policy underlying the Fourth :.. Amendment] to discourage citizens from aiding to the utmost of their ability in the apprehension of criminals”). And we understand a co-tenant’s legitimate self-interest in siding with the police to deflect suspicion raised by sharing quarters with a criminal, see 4 LaFave § 8.3(d), at 162, n. 72 (“The risk of being convicted of possession of drugs one knows are present and has tried to get the other occupant to remove is by no means insignificant”); cf. Schneckloth, 412 U. S., at 243 (evidence obtained pursuant to a consent search “may insure that a wholly innocent person is not wrongly charged with a criminal offense”).

But society can often have the benefit of these interests without relying on a theory of consent that ignores an inhabitant’s refusal to allow a warrantless search. The co-tenant acting on his own initiative may be able to deliver evidence to the police, Coolidge, supra, at 487-489 (suspect’s wife retrieved his guns from the couple’s house and turned them over to the police), and can tell the police what he knows, for use before a magistrate in getting a warrant.6 The reliance *117on a co-tenant’s information instead of disputed consent accords with the law’s general partiality toward “police action taken under a warrant [as against] searches and seizures without one,” United States v. Ventresca, 380 U. S. 102, 107 (1965); “the informed and deliberate determinations of magistrates empowered to issue warrants as to what searches and seizures are permissible under the Constitution are to be preferred over the hurried action of officers,” United States v. Lefkowitz, 285 U. S. 452, 464 (1932).

Nor should this established policy of Fourth Amendment law be undermined by the principal dissent’s claim that it shields spousal abusers and other violent co-tenants who will refuse to allow the police to enter a dwelling when their victims ask the police for help, post, at 138 (opinion of RobEETS, C. J.) (hereinafter the dissent). It is not that the dissent exaggerates violence in the home; we recognize that domestic abuse is a serious problem in the United States. See U. S. Dept, of Justice, National Institute of Justice, P. Tjaden & N. Thoennes, Full Report of the Prevalence, Incidence, and Consequences of Violence Against Women 25-26 (2000) (noting that over 20 million women and 6 million men will, in the course of their lifetimes, be the victims of intimate-partner abuse); U. S. Dept, of Health and Human Services, Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, Costs of Intimate Partner Violence Against Women in the United States 19 (2003) (finding that nearly 5.3 million intimate-partner victimizations, which result in close to 2 million injuries and 1,300 deaths, occur among women in the United States each year); U. S. Dept, of Justice, Bureau of Justice Statistics, Crime Data Brief, C. Rennison, Intimate Partner Violence, 1993-2001 (Feb. 2003) (noting that in 2001 intimate-partner violence made up 20% of violent crime against women); see also Becker, The Politics of Women’s *118Wrongs and the Bill of “Rights”: A Bicentennial Perspective, 59 U. Chi. L. Rev. 453, 507-508 (1992) (noting that women may feel physical insecurity in their homes as a result of abuse from domestic partners).

But this case has no bearing on the capacity of the police to protect domestic victims. The dissent’s argument rests on the failure to distinguish two different issues: when the police may enter without committing a trespass, and when the police may enter to search for evidence. No question has been raised, or reasonably could be, about the authority of the police to enter a dwelling to protect a resident from domestic violence; so long as they have good reason to believe such a threat exists, it would be silly to suggest that the police would commit a tort by entering, say, to give a complaining tenant the opportunity to collect belongings and get out safely, or to determine whether violence (or threat of violence) has just occurred or is about to (or soon will) occur, however much a spouse or other co-tenant objected. (And since the police would then be lawfully in the premises, there is no question that they could seize any evidence in plain view or take further action supported by any consequent probable cause, see Texas v. Brown, 460 U. S. 730, 737-739 (1983) (plurality opinion).) Thus, the question whether the police might lawfully enter over objection in order to provide any protection that might be reasonable is easily answered yes. See 4 LaFave § 8.3(d), at 161 (“[E]ven when . . . two persons quite clearly have equal rights in the place, as where two individuals are sharing an apartment on an equal basis, there may nonetheless sometimes exist a basis for giving greater recognition to the interests of one over the other.... [W]here the defendant has victimized the third-party ... the emergency nature of the situation is such that the third-party consent should validate a warrantless search despite defendant’s objections” (internal quotation marks omitted; third omission in original)). The undoubted right of the po*119lice to enter in order to protect a victim, however, has nothing to do with the question in this case, whether a search with the consent of one co-tenant is good against another, standing at the door and expressly refusing consent.7

None of the cases cited by the dissent support its improbable view that recognizing limits on merely evidentiary searches would compromise the capacity to protect a fearful occupant. In the circumstances of those cases, there is no danger that the fearful occupant will be kept behind the closed door of the house simply because the abusive tenant refuses to consent to a search. See United States v. Donlin, 982 F. 2d 31, 32 (CA1 1992) (victimized individual was already outside of her apartment when police arrived and, for all intents and purposes, within the protective custody of law enforcement officers); United States v. Hendrix, 595 F. 2d 883, 885-886 (CADC 1979) (per curiam) (even if the consent of the threatened co-occupant did not justify a warrantless search, the police entry was nevertheless allowable on exigent circumstances grounds); People v. Sanders, 904 P. 2d 1311, 1313-1315 (Colo. 1995) (en banc) (victimized individual gave her consent to search away from her home and was not present at the time of the police visit; alternatively, exigent circumstances existed to satisfy the warrantless exception); Brandon v. State, 778 P. 2d 221, 223-224 (Alaska App. 1989) (victimized individual consented away from her home and was not present at the time of the police visit); United States v. Davis, 290 F. 3d 1239, 1241 (CA10 2002) (immediate harm extinguished after husband “order[ed]” wife out of the home).

*120The dissent’s red herring aside, we know, of course, that alternatives to disputed consent will not always open the door to search for evidence that the police suspect is inside. The consenting tenant may simply not disclose enough information, or information factual enough, to add up to a showing of probable cause, and there may be no exigency to justify fast action. But nothing in social custom or its reflection in private law argues for placing a higher value on delving into private premises to search for evidence in the face of disputed consent, than on requiring clear justification before the government searches private living quarters over a resident’s objection. We therefore hold that a warrantless search of a shared dwelling for evidence over the express refusal of consent by a physically present resident cannot be justified as reasonable as to him on the basis of consent given to the police by another resident.8

E

There are two loose ends, the first being the explanation given in Matlock for the constitutional sufficiency of a co-tenant’s consent to enter and search: it “rests ... on mutual use of the property by persons generally having joint access or control for most purposes, so that it is reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right... .” 415 U. S., at 171, n. 7. If Matlock’s co-tenant is giving permission “in his own right,” how can his “own right” be eliminated by another tenant’s objection? The answer appears in the very footnote from which the quoted statement is taken: the “right” to admit the police to which Matlock refers is not an enduring and enforceable ownership right as understood by the *121private law of property, but is instead the authority recognized by customary social usage as having a substantial bearing on Fourth Amendment reasonableness in specific circumstances. Thus, to ask whether the consenting tenant has the right to admit the police when a physically present fellow tenant objects is not to question whether some property right may be divested by the mere objection of another. It is, rather, the question whether customary social understanding accords the consenting tenant authority powerful enough to prevail over the co-tenant’s objection. The Matlock Court did not purport to answer this question, a point made clear by another statement (which the dissent does not quote): the Court described the co-tenant’s consent as good against “the absent, nonconsenting” resident. Id., at 170.

The second loose end is the significance of Matlock and Rodriguez after today’s decision. Although the Matlock defendant was not present with the opportunity to object, he was in a squad car not far away; the Rodriguez defendant was actually asleep in the apartment, and the police might have roused him with a knock on the door before they entered with only the consent of an apparent co-tenant. If those cases are not to be undercut by today’s holding, we have to admit that we are drawing a fine line; if a potential defendant with self-interest in objecting is in fact at the door and objects, the co-tenant’s permission does not suffice for a reasonable search, whereas the potential objector, nearby but not invited to take part in the threshold colloquy, loses out.

This is the line we draw, and we think the formalism is justified. So long as there is no evidence that the police have removed the potentially objecting tenant from the entrance for the sake of avoiding a possible objection, there is practical value in the simple clarity of complementary rules, one recognizing the co-tenant’s permission when there is no fellow occupant on hand, the other according dispositive weight to the fellow occupant’s contrary indication when he *122expresses it. For the very reason that Rodriguez held it would be unjustifiably impractical to require the police to take affirmative steps to confirm the actual authority of a consenting individual whose authority was apparent, we think it would needlessly limit the capacity of the police to respond to ostensibly legitimate opportunities in the field if we were to hold that reasonableness required the police to take affirmative steps to find a potentially objecting co-tenant before acting on the permission they had already received. There is no ready reason to believe that efforts to invite a refusal would make a difference in many cases, whereas every co-tenant consent case would turn into a test about the adequacy of the police’s efforts to consult with a potential objector. Better to accept the formalism of distinguishing Matlock from this case than to impose a requirement, time consuming in the field and in the courtroom, with no apparent systemic justification. The pragmatic decision to accept the simplicity of this line is, moreover, supported by the substantial number of instances in which suspects who are asked for permission to search actually consent,9 albeit imprudently, a fact that undercuts any argument that the police should try to locate a suspected inhabitant because his denial of consent would be a foregone conclusion.

Ill

This case invites a straightforward application of the rule that a physically present inhabitant’s express refusal of consent to a police search is dispositive as to him, regardless of *123the consent of a fellow occupant. Scott Randolph’s refusal is clear, and nothing in the record justifies the search on grounds independent of Janet Randolph’s consent. The State does not argue that she gave any indication to the police of a need for protection inside the house that might have justified entry into the portion of the premises where the police found the powdery straw (which, if lawfully seized, could have been used when attempting to establish probable cause for the warrant issued later). Nor does the State claim that the entry and search should be upheld under the rubric of exigent circumstances, owing to some apprehension by the police officers that Scott Randolph would destroy evidence of drug use before any warrant could be obtained.

The judgment of the Supreme Court of Georgia is therefore affirmed.

It is so ordered.

Justice Alito took no part in the consideration or decision of this case.

Justice Stevens,

concurring.

The study of history for the purpose of ascertaining the original understanding of constitutional provisions is much like the study of legislative history for the purpose of ascertaining the intent of the lawmakers who enact statutes. In both situations the facts uncovered by the study are usually relevant but not necessarily dispositive. This case illustrates why even the most dedicated adherent to an approach to constitutional interpretation that places primary reliance on the search for original understanding would recognize the relevance of changes in our society.

At least since 1604 it has been settled that in the absence of exigent circumstances, a government agent has no right to enter a “house” or “castle” unless authorized to do so by a valid warrant. See Semayne’s Case, 5 Co. Rep. 91a, 77 Eng. Rep. 194 (K. B.). Every occupant of the home has a *124right — protected by the common law for centuries and by the Fourth Amendment since 1791 — to refuse entry. When an occupant gives his or her consent to enter, he or she is waiving a valuable constitutional right. To be sure that the waiver is voluntary, it is sound practice — a practice some Justices of this Court thought necessary to make the waiver voluntary1 — for the officer to advise the occupant of that right.2 The issue in this case relates to the content of the advice that the officer should provide when met at the door by a man and a woman who are apparently joint tenants or joint owners of the property.

In the 18th century, when the Fourth Amendment was adopted, the advice would have been quite different from what is appropriate today. Given the then-prevailing dramatic differences between the property rights of the husband and the far lesser rights of the wife, only the consent of the husband would matter. Whether “the master of the house” consented or objected, his decision would control. Thus if “original understanding” were to govern the outcome of this case, the search was clearly invalid because the husband did not consent. History, however, is not dispositive because it is now clear, as a matter of constitutional law, that *125the male and the female are equal partners. Reed v. Reed, 404 U. S. 71 (1971).

In today’s world the only advice that an officer could properly give should make it clear that each of the partners has a constitutional right that he or she may independently assert or waive. Assuming that both spouses are competent, neither one is a master possessing the power to override the other’s constitutional right to deny entry to their castle.

With these observations, I join the Court’s opinion.

Justice Breyer,

concurring.

If Fourth Amendment law forced us to choose between two bright-line rules, (1) a rule that always found one tenant’s consent sufficient to justify a search without a warrant and (2) a rule that never did, I believe we should choose the first. That is because, as The Chief Justice’s dissent points out, a rule permitting such searches can serve important law enforcement needs (for example, in domestic abuse cases), and the consenting party’s joint tenancy diminishes the objecting party’s reasonable expectation of privacy.

But the Fourth Amendment does not insist upon bright-line rules. Rather, it recognizes that no single set of legal rules can capture the ever-changing complexity of human life. It consequently uses the general terms “unreasonable searches and seizures.” And this Court has continuously emphasized that “Reasonableness ... is measured . . . by examining the totality of the circumstances.” Ohio v. Robinette, 519 U. S. 33, 39 (1996); see also Illinois v. Wardlow, 528 U. S. 119, 136 (2000) (Stevens, J., concurring in part and dissenting in part); Florida v. Bostick, 501 U. S. 429, 439 (1991); Michigan v. Chesternut, 486 U. S. 567, 572-573 (1988); Florida v. Royer, 460 U. S. 491, 506 (1983) (plurality opinion).

The circumstances here include the following: The search at issue was a search solely for evidence. The objecting *126party was present and made his objection known clearly and directly to the officers seeking to enter the house. The officers did not justify their search on grounds of possible evidence destruction. Cf. Thornton v. United States, 541 U. S. 615, 620-622 (2004); Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 623 (1989); Schmerber v. California, 384 U. S. 757, 770-771 (1966). And, as far as the record reveals, the officers might easily have secured the premises and sought a warrant permitting them to enter. See Illinois v. McArthur, 531 U. S. 326 (2001). Thus, the “totality of the circumstances” present here do not suffice to justify abandoning the Fourth Amendment’s traditional hostility to police entry into a home without a warrant.

I stress the totality of the circumstances, however, because, were the circumstances to change significantly, so should the result. The Court’s opinion does not apply where the objector is not present “and objecting].” Ante, at 121.

Moreover, the risk of an ongoing crime or other exigent circumstance can make a critical difference. Consider, for example, instances of domestic abuse. See ante, at 117-118. “Family disturbance calls . . . constitute the largest single category of calls received by police departments each year.” Mederer & Gelles, Compassion or Control: Intervention in Cases of Wife Abuse, 4 J. of Interpersonal Violence 25 (Mar. 1989) (emphasis deleted); see also, e. g., Office of the Attorney General, California Criminal Justice Statistics Center, Domestic Violence Related Calls for Assistance, 1987-2003, County by Year, http://ag.ca.gov/cjsc/publications/misc/ dvsr/tabs/ 8703.pdf (as visited Mar. 1, 2006, and available in Clerk of Court’s case file) (providing data showing that California police received an average of 207,848 domestic violence related calls each year); Cessato, Defenders Against Domestic Abuse, Washington Post, Aug. 25, 2002, p. B8 (“In the District [of Columbia], police report that almost half of roughly 39,000 violent crime calls received in 2000 involved domestic violence”); Zorza, Women Battering: High Costs *127and the State of the Law, Clearinghouse Review 383, 385 (Special Issue 1994) (“One-third of all police time is spent responding to domestic disturbance calls”). And, law enforcement officers must be able to respond effectively when confronted with the possibility of abuse.

If a possible abuse victim invites a responding officer to enter a home or consents to the officer’s entry request, that invitation (or consent) itself could reflect the victim’s fear about being left alone with an abuser. It could also indicate the availability of evidence, in the form of an immediate willingness to speak, that might not otherwise exist. In that context, an invitation (or consent) would provide a special reason for immediate, rather than later, police entry. And, entry following invitation or consent by one party ordinarily would be reasonable even in the face of direct objection by the other. That being so, contrary to The Chief Justice’s suggestion, post, at 139, today’s decision will not adversely affect ordinary law enforcement practices.

Given the case-specific nature of the Court’s holding, and with these understandings, I join the Court’s holding and its opinion.

Chief Justice Roberts,

with whom

Justice Scalia joins, dissenting.

The Court creates constitutional law by surmising what is typical when a social guest encounters an entirely atypical situation. The rule the majority fashions does not implement the high office of the Fourth Amendment to protect privacy, but instead provides protection on a random and happenstance basis, protecting, for example, a co-occupant who happens to be at the front door when the other occupant consents to a search, but not one napping or watching television in the next room. And the cost of affording such random protection is great, as demonstrated by the recurring cases in which abused spouses seek to authorize police entry into a home they share with a nonconsenting abuser.

*128The correct approach to the question presented is clearly mapped out in our precedents: The Fourth Amendment protects privacy. If an individual shares information, papers, or places with another, he assumes the risk that the other person will in turn share access to that information or those papers or places with the government. And just as an individual who has shared illegal plans or incriminating documents with another cannot interpose an objection when that other person turns the information over to the government, just because the individual happens to be present at the time, so too someone who shares a place with another cannot interpose an objection when that person decides to grant access to the police, simply because the objecting individual happens to be present.

A warrantless search is reasonable if police obtain the voluntary consent of a person authorized to give it. Co-occupants have “assumed the risk that one of their number might permit [a] common area to be searched.” United States v. Matlock, 415 U. S. 164, 171, n. 7 (1974). Just as Mrs. Randolph could walk upstairs, come down, and turn her husband’s cocaine straw over to the police, she can consent to police entry and search of what is, after all, her home, too.

I

In Illinois v. Rodriguez, 497 U. S. 177 (1990), this Court stated that “[w]hat [a person] is assured by the Fourth Amendment ... is not that no government search of his house will occur unless he consents; but that no such search will occur that is ‘unreasonable.’” Id., at 183. One element that can make a warrantless government search of a home “‘reasonable’” is voluntary consent. Id., at 184; Schneckloth v. Bustamonte, 412 U. S. 218, 219 (1973). Proof of voluntary consent “is not limited to proof that consent was given by the defendant,” but the government “may show that permission to search was obtained from a third party who possessed common authority over or other sufficient re*129lationship to the premises.” Matlock, supra, at 171. Today’s opinion creates an exception to this otherwise clear rule: A third-party consent search is unreasonable, and therefore constitutionally impermissible, if the co-occupant against whom evidence is obtained was present and objected to the entry and search.

This exception is based on what the majority describes as “widely shared social expectations” that “when people living together disagree over the use of their common quarters, a resolution must come through voluntary accommodation.” Ante, at 111, 113-114. But this fundamental predicate to the majority’s analysis gets us nowhere: Does the objecting co-tenant accede to the consenting co-tenant’s wishes, or the other way around? The majority’s assumption about voluntary accommodation simply leads to the common stalemate of two gentlemen insisting that the other enter a room first.

Nevertheless, the majority is confident in assuming — confident enough to incorporate its assumption into the Constitution — that an invited social guest who arrives at the door of a shared residence, and is greeted by a disagreeable co-occupant shouting “‘stay out,’” would simply go away. Ante, at 113. The Court observes that “no sensible person would go inside under those conditions,” ibid., and concludes from this that the inviting co-occupant has no “authority” to insist on getting her way over the wishes of her co-occupant, ante, at 114. But it seems equally accurate to say — based on the majority’s conclusion that one does not have a right to prevail over the express wishes of his co-occupant — that the objector has no “authority” to insist on getting his way over his co-occupant’s wish that her guest be admitted.

The fact is that a wide variety of differing social situations can readily be imagined, giving rise to quite different social expectations. A relative or good friend of one of two feuding roommates might well enter the apartment over the objection of the other roommate. The reason the invitee *130appeared at the door also affects expectations: A guest who came to celebrate an occupant’s birthday, or one who had traveled some distance for a particular reason, might not readily turn away simply because of a roommate’s objection. The nature of the place itself is also pertinent: Invitees may react one way if the feuding roommates share one room, differently if there are common areas from which the objecting roommate could readily be expected to absent himself. Altering the numbers might well change the social expectations: Invitees might enter if two of three co-occupants encourage them to do so, over one dissenter.

The possible scenarios are limitless, and slight variations in the fact pattern yield vastly different expectations about whether the invitee might be expected to enter or to go away. Such shifting expectations are not a promising foundation on which to ground a constitutional rule, particularly because the majority has no support for its basic assumption — that an invited guest encountering two disagreeing co-occupants would flee — beyond a hunch about how people would typically act in an atypical situation.

And in fact the Court has not looked to such expectations to decide questions of consent under the Fourth Amendment, but only to determine when a search has occurred and whether a particular person has standing to object to a search. For these latter inquiries, we ask whether a person has a subjective expectation of privacy in a particular place, and whether “the expectation [is] one that society is prepared to recognize as ‘reasonable.’” Katz v. United States, 389 U. S. 347, 361 (1967) (Harlan, J., concurring); see Minnesota v. Olson, 495 U. S. 91, 95-96, 100 (1990) (extending Katz test to standing inquiry). But the social expectations concept has not been applied to all questions arising under the Fourth Amendment, least of all issues of consent. A criminal might have a strong expectation that his longtime confidant will not allow the government to listen to their private conversations, but however profound his shock might be *131upon betrayal, government monitoring with the confidant’s consent is reasonable under the Fourth Amendment. See United States v. White, 401 U. S. 745, 752 (1971) (plurality opinion).

The majority suggests that “widely shared social expectations” are a “constant element in assessing Fourth Amendment reasonableness,” ante, at 111 (citing Rakas v. Illinois, 439 U. S. 128, 144, n. 12 (1978)), but that is not the case; the Fourth Amendment precedents the majority cites refer instead to a “legitimate expectation of privacy,” id., at 143, n. 12 (emphasis added; internal quotation marks omitted). Whatever social expectation the majority seeks to protect, it is not one of privacy. The very predicate giving rise to the question in cases of shared information, papers, containers, or places is that privacy has been shared with another. Our common social expectations may well be that the other person will not, in turn, share what we have shared with them with another — including the police — but that is the risk we take in sharing. If two friends share a locker and one keeps contraband inside, he might trust that his friend will not let others look inside. But by sharing private space, privacy has “already been frustrated” with respect to the locker-mate. United States v. Jacobsen, 466 U. S. 109, 117 (1984). If two roommates share a computer and one keeps pirated software on a shared drive, he might assume that his roommate will not inform the government. But that person has given up his privacy with respect to his roommate by saving the software on their shared computer.

A wide variety of often subtle social conventions may shape expectations about how we act when another shares with us what is otherwise private, and those conventions go by a variety of labels — courtesy, good manners, custom, protocol, even honor among thieves. The Constitution, however, protects not these but privacy, and once privacy has been shared, the shared information, documents, or places remain private only at the discretion of the confidant.

*132II

Our cases reflect this understanding. In United States v. White, we held that one party to a conversation can consent to government eavesdropping, and statements made by the other party will be admissible at trial. 401 U. S., at 752. This rule is based on privacy: “Inescapably, one contemplating illegal activities must realize and risk that his companions may be reporting to the police.... [I]f he has no doubts, or allays them, or risks what doubt he has, the risk is his.” Ibid.

The Court has applied this same analysis to objects and places as well. In Frazier v. Cupp, 394 U. S. 731 (1969), a duffel bag “was being used jointly” by two cousins. Id., at 740. The Court held that the consent of one was effective to result in the seizure of evidence used against both: “[I]n allowing [his cousin] to use the bag and in leaving it in his house, [the defendant] must be taken to have assumed the risk that [his cousin] would allow someone else to look inside.” Ibid.

As the Court explained in United States v. Jacobsen, supra:

“It is well settled that when an individual reveals private information to another, he assumes the risk that his confidant will reveal that information to the authorities, and if that occurs the Fourth Amendment does not prohibit governmental use of that information. Once frustration of the original expectation of privacy occurs, the Fourth Amendment does not prohibit governmental use of the now nonprivate information: ‘This Court has held repeatedly that the Fourth Amendment does not prohibit the obtaining of information revealed to a third party and conveyed by him to Government authorities, even if the information is revealed on the assumption that it will be used only for a limited purpose and the confidence placed in a third party will not be betrayed.’ ” *133Id., at 117 (quoting United States v. Miller, 425 U. S. 435, 443 (1976)).

The same analysis applies to the question whether our privacy can be compromised by those with whom we share common living space. If a person keeps contraband in common areas of his home, he runs the risk that his co-occupants will deliver the contraband to the police. In Coolidge v. New Hampshire, 403 U. S. 443 (1971), Mrs. Coolidge retrieved four of her husband’s guns and the clothes he was wearing the previous night and handed them over to police. We held that these items were properly admitted at trial because “when Mrs. Coolidge of her own accord produced the guns and clothes for inspection, ... it was not incumbent on the police to stop her or avert their eyes.” Id., at 489.

Even in our most private relationships, our observable actions and possessions are private at the discretion of those around us. A husband can request that his wife not tell a jury about contraband that she observed in their home or illegal activity to which she bore witness, but it is she who decides whether to invoke the testimonial marital privilege. Trammel v. United States, 445 U. S. 40, 53 (1980). In Trammel, we noted that the former rule prohibiting a wife from testifying about her husband’s observable wrongdoing at his say-so “goes far beyond making ‘every man’s house his castle,’ and permits a person to convert his house into ‘a den of thieves.’” Id., at 51-52 (quoting 5 J. Bentham, Rationale of Judicial Evidence 340 (1827)).

There is no basis for evaluating physical searches of shared space in a manner different from how we evaluated the privacy interests in the foregoing cases, and in fact the Court has proceeded along the same lines in considering such searches. In Matlock, police arrested the defendant in the front yard of a house and placed him in a squad car, and then obtained permission from Mrs. Graff to search a shared bedroom for evidence of Matlock’s bank robbery. 415 U. S., at 166. Police certainly could have assumed that Matlock *134would have objected were he consulted as he sat handcuffed in the squad car outside. And in Rodriguez, where Miss Fischer offered to facilitate the arrest of her sleeping boyfriend by admitting police into an apartment she apparently shared with him, 497 U. S., at 179, police might have noted that this entry was undoubtedly contrary to Rodriguez’s social expectations. Yet both of these searches were reasonable under the Fourth Amendment because Mrs. Graff had authority, and Miss Fischer apparent authority, to admit others into areas over which they exercised control, despite the almost certain wishes of their present co-occupants.

The common thread in our decisions upholding searches conducted pursuant to third-party consent is an understanding that a person “assume[s] the risk” that those who have access to and control over his shared property might consent to a search. Matlock, 415 U. S., at 171, n. 7. In Matlock, we explained that this assumption of risk is derived from a third party’s “joint access or control for most purposes” of shared property. Ibid. And we concluded that shared use of property makes it “reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right.” Ibid.

In this sense, the risk assumed by a joint occupant is comparable to the risk assumed by one who reveals private information to another. If a person has incriminating information, he can keep it private in the face of a request from police to share it, because he has that right under the Fifth Amendment. If a person occupies a house with incriminating information in it, he can keep that information private in the face of a request from police to search the house, because he has that right under the Fourth Amendment. But if he shares the information — or the house — with another, that other can grant access to the police in each instance.1

*135To the extent a person wants to ensure that his possessions will be subject to a consent search only due' to his own consent, he is free to place these items in an area over which others do not share access and control, be it a private room or a locked suitcase under a bed. Mr. Randolph acknowledged this distinction in his motion to suppress, where he differentiated his law office from the rest of the Randolph house by describing it as an area that “was solely in his control and dominion.” App. 3. As to a “common area,” however, co-occupants with “joint access or control” may consent to an entry and search. Matlock, supra, at 171, n. 7.

By emphasizing the objector’s presence and noting an occupant’s understanding that obnoxious guests might “be admitted in [one’s] absence,” ante, at 111, the majority appears to resurrect an agency theory of consent suggested in our early cases. See Stoner v. California, 376 U. S. 483, 489 (1964) (stating that a hotel clerk could not consent to a search of a guest’s room because the guest had not waived his rights *136“by word or deed, either directly or through an agent”); Chapman v. United States, 365 U. S. 610, 616-617 (1961). This agency theory is belied by the facts of Matlock and Rodriguez — both defendants were present but simply not asked for consent — and the Court made clear in those cases that a co-occupant’s authority to consent rested not on an absent occupant’s delegation of choice to an agent, but on the consenting co-occupant’s “joint access or control” of the property. Matlock, supra, at 171, n. 7; see Rodriguez, supra, at 181; United States v. McAlpine, 919 F. 2d 1461, 1464, n. 2 (CA10 1990) (“[A]gency analysis [was] put to rest by the Supreme Court’s reasoning in Matlock”).

The law acknowledges that although we might not expect our friends and family to admit the government into common areas, sharing space entails risk. A person assumes the risk that his co-occupants — just as they might report his illegal activity or deliver his contraband to the government — might consent to a search of areas over which they have access and control. See United States v. Karo, 468 U. S. 705, 726 (1984) (O’Connor, J., concurring in part and concurring in judgment) (finding it a “relatively easy case ... when two persons share identical, overlapping privacy interests in a particular place, container, or conversation. Here both share the power to surrender each other’s privacy to a third party”).

Ill

The majority states its rule as follows: “[A] warrantless search of a shared dwelling for evidence over the express refusal of consent by a physically present resident cannot be justified as reasonable as to him on the basis of consent given to the police by another resident.” Ante, at 120.

Just as the source of the majority’s rule is not privacy, so too the interest it protects cannot reasonably be described as such. That interest is not protected if a co-owner happens to be absent when the police arrive, in the backyard gardening, asleep in the next room, or listening to music *137through earphones so that only his co-occupant hears the knock on the door. That the rule is so random in its application confirms that it bears no real relation to the privacy protected by the Fourth Amendment. What the majority’s rule protects is not so much privacy as the good luck of a co-owner who just happens to be present at the door when the police arrive. Usually when the development of Fourth Amendment jurisprudence leads to such arbitrary lines, we take it as a signal that the rules need to be rethought. See California v. Acevedo, 500 U. S. 565, 574, 580 (1991). We should not embrace a rule at the outset that its sponsors appreciate will result in drawing fine, formalistic lines. See ante, at 121.

Rather than draw such random and happenstance lines— and pretend that the Constitution decreed them — the more reasonable approach is to adopt a rule acknowledging that shared living space entails a limited yielding of privacy to others, and that the law historically permits those to whom we have yielded our privacy to in turn cooperate with the government. Such a rule flows more naturally from our casés concerning Fourth Amendment reasonableness and is logically grounded in the concept of privacy underlying that Amendment.

The scope of the majority’s rule is not only arbitrary but obscure as well. The majority repeats several times that a present co-occupant’s refusal to permit entry renders the search unreasonable and invalid “as to him.” Ante, at 106, 120, 122. This implies entry and search would be reasonable “as to” someone else, presumably the consenting co-occupant and any other absent co-occupants. The normal Fourth Amendment rule is that items discovered in plain view are admissible if the officers were legitimately on the premises; if the entry and search were reasonable “as to” Mrs. Randolph, based on her consent, it is not clear why the cocaine straw should not be admissible “as to” Mr. Randolph, as discovered in plain view during a legitimate search “as *138to” Mrs. Randolph. The majority’s differentiation between entry focused on discovering whether domestic violence has occurred (and the consequent authority to seize items in plain view), and entry focused on searching for evidence of other crime, is equally puzzling. See ante, at 118-119. This Court has rejected subjective motivations of police officers in assessing Fourth Amendment questions, see Whren v. United States, 517 U. S. 806, 812-813 (1996), with good reason: The police do not need a particular reason to ask for consent to search, whether for signs of domestic violence or evidence of drug possession.

While the majority’s rule protects something random, its consequences are particularly severe. The question presented often arises when innocent co-tenants seek to disassociate or protect themselves from ongoing criminal activity. See, e. g., United States v. Hendrix, 595 F. 2d 883, 884 (CADC 1979) (per curiam) (wife asked police “ ‘to get her baby and take [a] sawed-off shotgun out of her house’”); People v. Cosme, 48 N. Y. 2d 286, 288-289, 293, 397 N. E. 2d 1319, 1320, 1323 (1979) (woman asked police to remove cocaine and a gun from a shared closet); United States v. Botsch, 364 F. 2d 542, 547 (CA2 1966). Under the majority’s rule, there will be many cases in which a consenting co-occupant’s wish to have the police enter is overridden by an objection from another present co-occupant. What does the majority imagine will happen, in a case in which the consenting co-occupant is concerned about the other’s criminal activity, once the door clicks shut? The objecting co-occupant may pause briefly to decide whether to destroy any evidence of wrongdoing or to inflict retribution on the consenting co-occupant first, but there can be little doubt that he will attend to both in short order. It is no answer to say that the consenting co-occupant can depart with the police; remember that it is her home, too, and the other co-occupant’s very presence, which allowed him to object, may also prevent the consenting co-occupant from doing more than urging the police to enter.

*139Perhaps the most serious consequence of the majority’s rule is its operation in domestic abuse situations, a context in which the present question often arises. See Rodriguez, 497 U. S., at 179; United States v. Donlin, 982 F. 2d 31 (CA1 1992); Hendrix, supra; People v. Sanders, 904 P. 2d 1311 (Colo. 1995) (en banc); Brandon v. State, 778 P. 2d 221 (Alaska App. 1989). While people living together might typically be accommodating to the wishes of their co-tenants, requests for police assistance may well come from co-inhabitants who are having a disagreement. The Court concludes that because “no sensible person would go inside” in the face of disputed consent, ante, at 113, and the consenting co-tenant thus has “no recognized authority” to insist on the guest’s admission, ante, at 114, a “police officer [has] no better claim to reasonableness in entering than the officer would have in the absence of any consent at all,” ibid. But the police officer’s superior claim to enter is obvious: Mrs. Randolph did not invite the police to join her for dessert and coffee; the officer’s precise purpose in knocking on the door was to assist with a dispute between the Randolphs — one in which Mrs. Randolph felt the need for the protective presence of the police. The majority’s rule apparently forbids police from entering to assist with a domestic dispute if the abuser whose behavior prompted the request for police assistance objects.2

*140The majority acknowledges these concerns, but dismisses them on the ground that its rule can be expected to give rise to exigent situations, and police can then rely on an exigent circumstances exception to justify entry. Ante, at 116-117, n. 6. This is a strange way to justify a rule, and the fact that alternative justifications for entry might arise does not show that entry pursuant to consent is unreasonable. In addition, it is far from clear that an exception for emergency entries suffices to protect the safety of occupants in domestic disputes. See, e. g., United States v. Davis, 290 F. 3d 1239, 1240-1241 (CA10 2002) (finding no exigent circumstances justifying entry when police responded to a report of domestic abuse, officers heard no noise upon arrival, defendant told officers that his wife was out of town, and wife then appeared at the door seemingly unharmed but resisted husband’s efforts to close the door).

Rather than give effect to a consenting spouse’s authority to permit entry into her house to avoid such situations, the majority again alters established Fourth Amendment rules to defend giving veto power to the objecting spouse. In response to the concern that police might be turned away under its rule before entry can be justified based on exigency, the majority creates a new rule: A “good reason” to enter, coupled with one occupant’s consent, will ensure that a police officer is “lawfully in the premises.” Ante, at 118. As support for this “consent plus a good reason” rule, the majority cites a treatise, which itself refers only to emergency entries. Ibid, (citing 4 W. LaFave, Search and Seizure § 8.3(d), p. 161 (4th ed. 2004)). For the sake of defending what it concedes are fine, formalistic lines, the ma*141jority spins out an entirely new framework for analyzing exigent circumstances. Police may now enter with a “good reason” to believe that “violence (or threat of violence) has just occurred or is about to (or soon will) occur.” Ante, at 118. And apparently a key factor allowing entry with a “good reason” short of exigency is the very consent of one co-occupant the majority finds so inadequate in the first place.

The majority’s analysis alters a great deal of established Fourth Amendment law. The majority imports the concept of “social expectations,” previously used only to determine when a search has occurred and whether a particular person has standing to object to a search, into questions of consent. Ante, at 111, 113. To determine whether entry and search are reasonable, the majority considers a police officer’s subjective motive in asking for consent, which we have otherwise refrained from doing in assessing Fourth Amendment questions. Ante, at 118. And the majority creates a new exception to the warrant requirement to justify warrantless entry short of exigency in potential domestic abuse situations. Ibid.

Considering the majority’s rule is solely concerned with protecting a person who happens to be present at the door when a police officer asks his co-occupant for consent to search, but not one who is asleep in the next room or in the backyard gardening, the majority has taken a great deal of pain in altering Fourth Amendment doctrine, for precious little (if any) gain in privacy. Perhaps one day, as the consequences of the majority’s analytic approach become clearer, today’s opinion will be treated the same way the majority treats our opinions in Matlock and Rodriguez — as a “loose end” to be tied up. Ante, at 121.

One of the concurring opinions states that if it had to choose between a rule that a co-tenant’s consent was valid or a rule that it was not, it would choose the former. Ante, at 125 (opinion of Breyer, J.). The concurrence advises, *142however, that “no single set of legal rules can capture the ever-changing complexity of human life,” ibid., and joins what becomes the majority opinion, “[g]iven the case-specific nature of the Court’s holding,” ante, at 127. What the majority establishes, in its own terms, is “the rule that a physically present inhabitant’s express refusal of consent to a police search is dispositive as to him, regardless of the consent of a fellow occupant.” Ante, at 122-123 (emphasis added). The concurrence joins with the apparent “understandin[g]” that the majority’s “rule” is not a rule at all, but simply a “case-specific” holding. Ante, at 127 (opinion of Breyer, J.). The end result is a complete lack of practical guidance for the police in the field, let alone for the lower courts.

* *

Our third-party consent cases have recognized that a person who shares common areas with others “assume[s] the risk that one of their number might permit the common area to be searched.” Matlock, 415 U. S., at 171, n. 7. The majority reminds us, in high tones, that a man’s home is his castle, ante, at 115, but even under the majority’s rule, it is not his castle if he happens to be absent, asleep in the keep, or otherwise engaged when the constable arrives at the gate. Then it is his co-owner’s castle. And, of course, it is not his castle if he wants to consent to entry, but his co-owner objects. Rather than constitutionalize such an arbitrary rule, we should acknowledge that a decision to share a private place, like a decision to share a secret or a confidential document, necessarily entails the risk that those with whom we share may in turn choose to share — for their own protection or for other reasons — with the police.

I respectfully dissent.

Justice Scalia,

dissenting.

I join the dissent of The Chief Justice, but add these few words in response to Justice Stevens’ concurrence.

*143It is not as clear to me as it is to Justice Stevens that, at the time the Fourth Amendment was adopted, a police officer could enter a married woman’s home over her objection, and could not enter with only her consent. Nor is it clear to me that the answers to these questions depended solely on who owned the house. It is entirely clear, however, that if the matter did depend solely on property rights, a latter-day alteration of property rights would also produce a latter-day alteration of the Fourth Amendment outcome— without altering the Fourth Amendment itself.

Justice Stevens’ attempted critique of originalism confuses the original import of the Fourth Amendment with the background sources of law to which the Amendment, on its original meaning, referred. From the date of its ratification until well into the 20th century, violation of the Amendment was tied to common-law trespass. See Kyllo v. United States, 533 U. S. 27, 31-32 (2001); see also California v. Acevedo, 500 U. S. 565, 581, 583 (1991) (SCALIA, J., concurring in judgment). On the basis of that connection, someone who had power to license the search of a house by a private party could authorize a police search. See 1 Restatement of Torts § 167, and Comment b (1934); see also Williams v. Howard, 110 S. C. 82, 96 S. E. 251 (1918); Fennemore v. Armstrong, 29 Del. 35, 96 A. 204 (Super. Ct. 1915). The issue of who could give such consent generally depended, in turn, on “historical and legal refinements” of property law. United States v. Matlock, 415 U. S. 164, 171, n. 7 (1974). As property law developed, individuals who previously could not authorize a search might become able to do so, and those who once could grant such consent might no longer have that power. But changes in the law of property to which the Fourth Amendment referred would not alter the Amendment’s meaning: that anyone capable of authorizing a search by a private party could consent to a warrantless search by the police.

*144There is nothing new or surprising in the proposition that our unchanging Constitution refers to other bodies of law that might themselves change. The Fifth Amendment provides, for instance, that “private property” shall not “be taken for public use, without just compensation”; but it does not purport to define property rights. We have consistently held that “the existence of a property interest is determined by reference to ‘existing rules or understandings that stem from an independent source such as state law.’” Phillips v. Washington Legal Foundation, 524 U. S. 156, 164 (1998) (quoting Board of Regents of State Colleges v. Roth, 408 U. S. 564, 577 (1972)). The same is true of the Fourteenth Amendment Due Process Clause’s protection of “property.” See Castle Rock v. Gonzales, 545 U. S. 748, 756 (2005). This reference to changeable law presents no problem for the originalist. No one supposes that the meaning of the Constitution changes as States expand and contract property rights. If it is indeed true, therefore, that a wife in 1791 could not authorize the search of her husband’s house, the fact that current property law provides otherwise is no more troublesome for the originalist than the well-established fact that a State must compensate its takings of even those property rights that did not exist at the time of the founding.

In any event, Justice Stevens’ panegyric to the equal rights of women under modern property law does not support his conclusion that “[ajssuming . . . both spouses are competent, neither one is a master possessing the power to override the other’s constitutional right to deny entry to their castle.” Ante, at 125. The issue at hand is what to do when there is a conflict between two equals. Now that women have authority to consent, as Justice Stevens claims men alone once did, it does not follow that the spouse who refuses consent should be the winner of the contest. Justice Stevens could just as well have followed the same historical developments to the opposite conclusion: Now that *145“the male and the female are equal partners,” ibid., and women can consent to a search of their property, men can no longer obstruct their wishes. Men and women are no more “equal” in the majority’s regime, where both sexes can veto each other’s consent, than on the dissent’s view, where both sexes cannot.

Finally, I must express grave doubt that today’s decision deserves Justice Stevens’ celebration as part of the forward march of women’s equality. Given the usual patterns of domestic violence, how often can police be expected to encounter the situation in which a man urges them to enter the home while a woman simultaneously demands that they stay out? The most common practical effect of today’s decision, insofar as the contest between the sexes is concerned, is to give men the power to stop women from allowing police into their homes — which is, curiously enough, precisely the power that Justice Stevens disapprovingly presumes men had in 1791.

Justice Thomas,

dissenting.

The Court has long recognized that “[i]t is an act of responsible citizenship for individuals to give whatever information they may have to aid in law enforcement.” Miranda v. Arizona, 384 U. S. 436, 477-478 (1966). Consistent with this principle, the Court held in Coolidge v. New Hampshire, 403 U. S. 443 (1971), that no Fourth Amendment search occurs where, as here, the spouse of an accused voluntarily leads the police to potential evidence of wrongdoing by the accused. Id., at 486-490. Because Coolidge squarely controls this case, the Court need not address whether police could permissibly have conducted a general search of the Randolph home, based on Mrs. Randolph’s consent. I respectfully dissent.

In the instant case, Mrs. Randolph told police responding to a domestic dispute that respondent was using a substan*146tial quantity of cocaine. Upon police request, she consented to a general search of her residence to investigate her statements. However, as the Court’s recitation of the facts demonstrates, ante, at 107, the record is clear that no such general search occurred. Instead, Sergeant Brett Murray asked Mrs. Randolph where the cocaine was located, and she showed him to an upstairs bedroom, where he saw the “piece of cut straw” on a dresser. Corrected Tr. of Motion to Suppression Hearing in Case No. 2001R-699 (Super. Ct. Sumter Cty., Ga., Oct. 3, 2002), pp. 8-9. Upon closer examination, Sergeant Murray observed white residue on the straw, and concluded the straw had been used for ingesting cocaine. Id., at 8. He then collected the straw and the residue as evidence. Id., at 9.

Sergeant Murray’s entry into the Randolphs’ home at the invitation of Mrs. Randolph to be shown evidence of respondent’s cocaine use does not constitute a Fourth Amendment search. Under this Court’s precedents, only the action of an agent of the government can constitute a search within the meaning of the Fourth Amendment, because that Amendment “was intended as a restraint upon the activities of sovereign authority, and was not intended to be a limitation upon other than governmental agencies.” Burdeau v. McDowell, 256 U. S. 465, 475 (1921) (emphasis added). See also Coolidge, 403 U. S., at 487. Applying this principle in Coolidge, the Court held that when a citizen leads police officers into a home shared with her spouse to show them evidence relevant to their investigation into a crime, that citizen is not acting as an agent of the police, and thus no Fourth Amendment search has occurred. Id., at 488-498.

Review of the facts in Coolidge clearly demonstrates that it governs this case. While the police interrogated Coolidge as part of their investigation into a murder, two other officers were sent to his house to speak with his wife. Id., at 485. During the course of questioning Mrs. Coolidge, the *147police asked whether her husband owned any guns. Id., at 486. Mrs. Coolidge replied in the affirmative, and offered to retrieve the weapons for the police, apparently operating under the assumption that doing so would help to exonerate her husband. Ibid. The police accompanied Mrs. Coolidge to the bedroom to collect the guns, as well as clothing that Mrs. Coolidge told them her husband had been wearing the night of the murder. Ibid.

Before this Court, Coolidge argued that the evidence of the guns and clothing should be suppressed as the product of an unlawful search because Mrs. Coolidge was acting as an “‘instrument,’” or agent, of the police by complying with a “ ‘demand’ ” made by them. Id., at 487. The Court recognized that, had Mrs. Coolidge sought out the guns to give to police wholly on her own initiative, “there can be no doubt under existing law that the articles would later have been admissible in evidence.” Ibid. That she did so in cooperation with police pursuant to their request did not transform her into their agent; after all, “it is no part of the policy underlying the Fourth and Fourteenth Amendments to discourage citizens from aiding to the utmost of their ability in the apprehension of criminals.” Id., at 488. Because the police were “acting normally and properly” when they asked about any guns, and questioning Mrs. Coolidge about the clothing was “logical and in no way coercive,” the Fourth Amendment did not require police to “avert their eyes” when Mrs. Coolidge produced the guns and clothes for inspection.1 Id., at 488-489.

*148This case is indistinguishable from Coolidge, compelling the conclusion that Mrs. Randolph was not acting as an agent of the police when she admitted Sergeant Murray into her home and led him to the incriminating evidence.2 Just as Mrs. Coolidge could, of her own accord, have offered her husband’s weapons and clothing to the police without implicating the Fourth Amendment, so too could Mrs. Randolph have simply retrieved the straw from the house and given it to Sergeant Murray. Indeed, the majority appears to concede as much. Ante, at 116 (“The co-tenant acting on his own initiative may be able to deliver evidence to the police, Coolidge, supra, at 487-489 ..., and can tell the police what he knows, for use before a magistrate in getting a warrant”). Drawing a constitutionally significant distinction between what occurred here and Mrs. Randolph’s independent production of the relevant evidence is both inconsistent with Coolidge and unduly formalistic.3

Accordingly, the trial court appropriately denied respondent’s motion to suppress the evidence Mrs. Randolph pro*149vided to the police and the evidence obtained as a result of the consequent search warrant. I would therefore reverse the judgment of the Supreme Court of Georgia.

OPINION OF THE COURT

[563 U.S. 455]

Justice Alito

delivered the opinion of the Court.

It is well established that “exigent circumstances,” including the need to prevent the destruction of evidence, permit police officers to conduct an otherwise permissible search without first obtaining a warrant. In this case, we consider whether this rule applies when police, by knocking on the door of a residence and announcing their presence, cause the occupants to attempt to destroy evidence. The Kentucky Supreme Court held that the exigent circumstances rule does not apply in the case at hand because the police should have foreseen that their conduct would prompt the occupants to attempt to destroy evidence. We reject this interpretation of the exigent circumstances rule. The conduct of the police prior to their entry into the apartment was entirely lawful. They did not violate the Fourth Amendment or threaten to do so. In such a situation, the exigent circumstances rule applies.

I

A

This case concerns the search of an apartment in Lexington, Kentucky. Police officers set up a controlled buy of crack cocaine outside an apartment complex. Undercover

[563 U.S. 456]

Officer Gibbons watched the deal take place from an unmarked car in a nearby parking lot. After the deal occurred, Gibbons radioed uniformed officers to move in on the suspect. He told the officers that the suspect was moving quickly toward the breezeway of an apartment building, and he urged them to “hurry up and get there” before the suspect entered an apartment. App. 20.

In response to the radio alert, the uniformed officers drove into the nearby parking lot, left their vehicles, and ran to the breezeway. Just as they entered the breezeway, they heard a door shut and detected a very strong odor of burnt marijuana. At the end of the breezeway, the officers saw two apartments, one on the left and one on the right, and they did not know which apartment the suspect had entered. Gibbons had radioed that the suspect was running into the apartment on the right, but the officers did not hear this statement because they had already left their vehicles. Because they smelled marijuana smoke emanating from the apartment on the left, they approached the door of that apartment.

Officer Steven Cobb, one of the uniformed officers who approached the door, testified that the officers banged on the left apartment door “as loud as [they] could” and announced, “ ‘This is the police’ ” or “ ‘Police, police, police.’ ” Id., at 22-23. Cobb said that “[a]s soon as [the officers] started banging on the door,” they “could hear people inside moving,” and “ [i] t sounded as [though] things were being moved inside the apartment.” Id., *873at 24. These noises, Cobb testified, led the officers to believe that drug-related evidence was about to be destroyed.

At that point, the officers announced that they “were going to make entry inside the apartment.” Ibid. Cobb then kicked in the door, the officers entered the apartment, and they found three people in the front room: respondent Hollis King, respondent’s girlfriend, and a guest who was smoking

[563 U.S. 457]

marijuana.1 The officers performed a protective sweep of the apartment during which they saw marijuana and powder cocaine in plain view. In a subsequent search, they also discovered crack cocaine, cash, and drug paraphernalia.

Police eventually entered the apartment on the right. Inside, they found the suspected drug dealer who was the initial target of their investigation.

B

In the Fayette County Circuit Court, a grand jury charged respondent with trafficking in marijuana, first-degree trafficking in a controlled substance, and second-degree persistent felony offender status. Respondent filed a motion to suppress the evidence from the warrantless search, but the Circuit Court denied the motion. The Circuit Court concluded that the officers had probable cause to investigate the marijuana odor and that the officers “properly conducted [the investigation] by initially knocking on the door of the apartment unit and awaiting the response or consensual entry.” App. to Pet. for Cert. 9a. Exigent circumstances justified the war-rantless entry, the court held, because “there was no response at all to the knocking,” and because “Officer Cobb heard movement in the apartment which he reasonably concluded were persons in the act of destroying evidence, particularly narcotics because of the smell.” Ibid. Respondent then entered a conditional guilty plea, reserving his right to appeal the denial of his suppression motion. The court sentenced respondent to 11 years’ imprisonment.

The Kentucky Court of Appeals affirmed. It held that exigent circumstances justified the warrantless entry because

[563 U.S. 458]

the police reasonably believed that evidence would be destroyed. The police did not impermis-sibly create the exigency, the court explained, because they did not deliberately evade the warrant requirement.

The Supreme Court of Kentucky reversed. 302 S.W.3d 649 (2010). As a preliminary matter, the court observed that there was “certainly some question as to whether the sound of persons moving [inside the apartment] was sufficient to establish that evidence was being destroyed.” Id., at 655. But the court did not answer that question. Instead, it “assume [d] for the purpose of argument that exigent circumstances existed.” Ibid.

To determine whether police imper-missibly created the exigency, the Supreme Court of Kentucky announced a two-part test. First, the court held, police cannot “deliberately creat[e] the exigent circumstances with the bad faith intent to avoid the warrant *874requirement.” Id., at 656 (internal quotation marks omitted). Second, even absent bad faith, the court concluded, police may not rely on exigent circumstances if “it was reasonably foreseeable that the investigative tactics employed by the police would create the exigent circumstances.” Ibid. (internal quotation marks omitted). Although the court found no evidence of bad faith, it held that exigent circumstances could not justify the search because it was reasonably foreseeable that the occupants would destroy evidence when the police knocked on the door and announced their presence. Ibid.

We granted certiorari. 561 U.S. 1057, 131 S. Ct. 61, 177 L. Ed. 2d 1150 (2010).2

[563 U.S. 459]

II

A

The Fourth Amendment provides:

“The 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 text of the Amendment thus expressly imposes two requirements. First, all searches and seizures must be reasonable. Second, a warrant may not be issued unless probable cause is properly established and the scope of the authorized search is set out with particularity. See Payton v. New York, 445 U.S. 573, 584, 100 S. Ct. 1371, 63 L. Ed. 2d 639 (1980).

Although the text of the Fourth Amendment does not specify when a search warrant must be obtained, this Court has inferred that a warrant must generally be secured. “It is a ‘basic principle of Fourth Amendment law,’ ” we have often said, “ ‘that searches and seizures inside a home without a warrant are presumptively unreasonable.’ ” Brigham City v. Stuart, 547 U.S. 398, 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650 (2006) (quoting Groh v. Ramirez, 540 U.S. 551, 559, 124 S. Ct. 1284, 157 L. Ed. 2d 1068 (2004)). But we have also recognized that this presumption may be overcome in some circumstances because “the ultimate touchstone of the Fourth Amendment is ‘reasonableness.’ ” Brigham City, supra, at 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650; see also Michigan v. Fisher, 558 U.S. 45, 47, 130 S. Ct. 546, 175 L. Ed. 2d 410 (2009) (per curiam). Accordingly, the warrant requirement is subject to certain reasonable exceptions. Brigham City, supra, at 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650.

[563 U.S. 460]

One well-recognized exception applies when “ ‘the exigencies of the situation’ make the needs of law enforcement so compelling that [a] war-*875rantless search is objectively reasonable under the Fourth Amendment.” Mincey v. Arizona, 437 U.S. 385, 394, 98 S. Ct. 2408, 57 L. Ed. 2d 290 (1978); see also Payton, supra, at 590, 100 S. Ct. 1371, 63 L. Ed. 2d 639 (“[T]he Fourth Amendment has drawn a firm line at the entrance to the house. Absent exigent circumstances, that threshold may not reasonably be crossed without a warrant”).

This Court has identified several exigencies that may justify a warrant-less search of a home. See Brigham City, 547 U.S., at 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650. Under the “emergency aid” exception, for example, “officers may enter a home without a warrant to render emergency assistance to an injured occupant or to protect an occupant from imminent injury.” Ibid.; see also, e.g., Fisher, supra, at 49, 130 S. Ct. 546, 175 L. Ed. 2d 410 (upholding warrant-less home entry based on emergency aid exception). Police officers may enter premises without a warrant when they are in hot pursuit of a fleeing suspect. See United States v. Santana, 427 U.S. 38, 42-43, 96 S. Ct. 2406, 49 L. Ed. 2d 300 (1976). And—what is relevant here—the need “to prevent the imminent destruction of evidence” has long been recognized as a sufficient justification for a warrantless search. Brigham City, supra, at 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650; see also Georgia v. Randolph, 547 U.S. 103, 116, n. 6, 126 S. Ct. 1515, 164 L. Ed. 2d 208 (2006); Minnesota v. Olson, 495 U.S. 91, 100, 110 S. Ct. 1684, 109 L. Ed. 2d 85 (1990).3

[563 U.S. 461]

B

Over the years, lower courts have developed an exception to the exigent circumstances rule, the so-called “police-created exigency” doctrine. Under this doctrine, police may not rely on the need to prevent destruction of evidence when that exigency was “created” or “manufactured” by the conduct of the police. See, e.g., United States v. Chambers, 395 F.3d 563, 566 (CA6 2005) (“[F]or a war-rantless search to stand, law enforcement officers must be responding to an unanticipated exigency rather than simply creating the exigency for themselves”); United States v. Gould, 364 F.3d 578, 590 (CA5 2004) (en banc) (“[A]lthough exigent circumstances may justify a warrantless probable cause entry into the home, they will not do so if the exigent circumstances were manufactured by the agents” (internal quotation marks omitted)).

In applying this exception for the “creation” or “manufacturing” of an exigency by the police, courts require something more than mere proof that fear of detection by the police caused the destruction of evidence. An additional showing is obviously needed because, as the Eighth Circuit has recognized, “in some sense the police *876always create the exigent circumstances.” United States v. Duchi, 906 F.2d 1278, 1284 (1990). That is to say, in the vast majority of cases in which evidence is destroyed by persons who are engaged in illegal conduct, the reason for the destruction is fear that the evidence will fall into the hands of law enforcement. Destruction of evidence issues probably occur most frequently in drug cases because drugs may be easily destroyed by flushing them down a toilet or rinsing them down a drain. Persons in possession of valuable drugs are unlikely to destroy them unless they fear discovery by the police. Consequently, a rule that precludes the police from making a warrantless entry to prevent the destruction of evidence whenever their conduct causes the exigency would

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unreasonably shrink the reach of this well-established exception to the warrant requirement.

Presumably for the purpose of avoiding such a result, the lower courts have held that the police-created exigency doctrine requires more than simple causation, but the lower courts have not agreed on the test to be applied. Indeed, the petition in this case maintains that “[t]here are currently five different tests being used by the United States Courts of Appeals,” Pet. for Cert. 11, and that some state courts have crafted additional tests, id., at 19-20.

Ill

A

Despite the welter of tests devised by the lower courts, the answer to the question presented in this case follows directly and clearly from the principle that permits warrantless searches in the first place. As previously noted, warrantless searches are allowed when the circumstances make it reasonable, within the meaning of the Fourth Amendment, to dispense with the warrant requirement. Therefore, the answer to the question before us is that the exigent circumstances rule justifies a warrantless search when the conduct of the police preceding the exigency is reasonable in the same sense. Where, as here, the police did not create the exigency by engaging or threatening to engage in conduct that violates the Fourth Amendment, warrantless entry to prevent the destruction of evidence is reasonable and thus allowed.4

We have taken a similar approach in other cases involving warrantless searches. For example, we have held that law

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enforcement officers may seize evidence in plain view, provided that they have not violated the Fourth Amendment in arriving at the spot from which the observation of the evidence is made. See Horton v. California, 496 U.S. 128, 136-140, 110 S. Ct. 2301, 110 L. Ed. 2d 112 (1990). As we put it in Horton, “[i]t is ... an essential predicate to any valid war-rantless seizure of incriminating evidence that the officer did not violate the Fourth Amendment in arriving at the place from which the evidence could be plainly viewed.” Id., at 136, 110 S. Ct. 2301, 110 L. Ed. 2d 112. So long as this prerequisite is satisfied, however, it does not matter that the officer who makes the observation *877may have gone to the spot from which the evidence was seen with the hope of being able to view and seize the evidence. See id., at 138, 110 S. Ct. 2301, 110 L. Ed. 2d 112 (“The fact that an officer is interested in an item of evidence and fully expects to find it in the course of a search should not invalidate its seizure”). Instead, the Fourth Amendment requires only that the steps preceding the seizure be lawful. See id., at 136-137, 110 S. Ct. 2301, 110 L. Ed. 2d 112.

Similarly, officers may seek consent-based encounters if they are lawfully present in the place where the consensual encounter occurs. See INS v. Delgado, 466 U.S. 210, 217, n. 5, 104 S. Ct. 1758, 80 L. Ed. 2d 247 (1984) (noting that officers who entered into consent-based encounters with employees in a factory building were “lawfully present [in the factory] pursuant to consent or a warrant”). If consent is freely given, it makes no difference that an officer may have approached the person with the hope or expectation of obtaining consent. See id., at 216, 104 S. Ct. 1758, 80 L. Ed. 2d 247 (“While most citizens will respond to a police request, the fact that people do so, and do so without being told they are free not to respond, hardly eliminates the consensual nature of the response”).

B

Some lower courts have adopted a rule that is similar to the one that we recognize today. See United States v. MacDonald, 916 F.2d 766, 772 (CA2 1990) (en banc) ( law enforcement officers “do not impermissibly create exigent circumstances”

[563 U.S. 464]

when they “act in an entirely lawful manner”); State v. Robinson, 2010 WI 80, ¶32, 327 Wis. 2d 302, 326-328, 786 N.W.2d 463, 475-476 (2010). But others, including the Kentucky Supreme Court, have imposed additional requirements that are unsound and that we now reject.

Bad faith. Some courts, including the Kentucky Supreme Court, ask whether law enforcement officers “ ‘deliberately created the exigent circumstances with the bad faith intent to avoid the warrant requirement.’ ” 302 S.W.3d, at 656 (quoting Gould, 364 F.3d, at 590); see also, e.g., Chambers, 395 F.3d, at 566; United States v. Socey, 846 F.2d 1439, 1448 (CADC 1988); United States v. Rengifo, 858 F.2d 800, 804 (CA1 1988).

This approach is fundamentally inconsistent with our Fourth Amendment jurisprudence. “Our cases have repeatedly rejected” a subjective approach, asking only whether “the circumstances, viewed objectively, justify the action.” Brigham City, 547 U.S., at 404, 126 S. Ct. 1943, 164 L. Ed. 2d 650 (alteration and internal quotation marks omitted); see also Fisher, 558 U.S., at 47-49, 130 S. Ct. 546, 175 L. Ed. 2d 410. Indeed, we have never held, outside limited contexts such as an “inventory search or administrative inspection ..., that an officer’s motive invalidates objectively justifiable behavior under the Fourth Amendment.” Whren v. United States, 517 U.S. 806, 812, 116 S. Ct. 1769, 135 L. Ed. 2d 89 (1996); see also Brigham City, supra, at 405, 126 S. Ct. 1943, 164 L. Ed. 2d 650.

The reasons for looking to objective factors, rather than subjective intent, are clear. Legal tests based on reasonableness are generally objective, and this Court has long taken the view that “evenhanded law enforcement is best achieved by the application of objective standards of conduct, rather than standards that depend upon the *878subjective state of mind of the officer.” Horton, supra, at 138, 110 S. Ct. 2301, 110 L. Ed. 2d 112.

Reasonable foreseeability. Some courts, again including the Kentucky Supreme Court, hold that police may not rely on an exigency if “ ‘it was reasonably foreseeable that the investigative tactics employed by the police would create the

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exigent circumstances.’ ” 302 S.W.3d, at 656 (quoting Mann v. State, 357 Ark. 159, 172, 161 S.W.3d 826, 834 (2004)); see also, e.g., United States v. Mowatt, 513 F.3d 395, 402 (CA4 2008). Courts applying this test have invalidated warrantless home searches on the ground that it was reasonably foreseeable that police officers, by knocking on the door and announcing their presence, would lead a drug suspect to destroy evidence. See, e.g., id., at 402-403; 302 S.W.3d, at 656.

Contrary to this reasoning, however, we have rejected the notion that police may seize evidence without a warrant only when they come across the evidence by happenstance. In Horton, as noted, we held that the police may seize evidence in plain view even though the officers may be “interested in an item of evidence and fully expec[t] to find it in the course of a search.” 496 U.S., at 138, 110 S. Ct. 2301, 110 L. Ed. 2d 112.

Adoption of a reasonable foreseeability test would also introduce an unacceptable degree of unpredictability. For example, whenever law enforcement officers knock on the door of premises occupied by a person who may be involved in the drug trade, there is some possibility that the occupants may possess drugs and may seek to destroy them. Under a reasonable foreseeability test, it would be necessary to quantify the degree of predictability that must be reached before the police-created exigency doctrine comes into play.

A simple example illustrates the difficulties that such an approach would produce. Suppose that the officers in the present case did not smell marijuana smoke and thus knew only that there was a 50% chance that the fleeing suspect had entered the apartment on the left rather than the apartment on the right. Under those circumstances, would it have been reasonably foreseeable that the occupants of the apartment on the left would seek to destroy evidence upon learning that the police were at the door? Or suppose that the officers knew only that the suspect had disappeared into one of the apartments on a floor with 3, 5, 10, or even 20

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units? If the police chose a door at random and knocked for the purpose of asking the occupants if they knew a person who fit the description of the suspect, would it have been reasonably foreseeable that the occupants would seek to destroy evidence?

We have noted that “[t]he calculus of reasonableness must embody allowance for the fact that police officers are often forced to make split-second judgments—in circumstances that are tense, uncertain, and rapidly evolving.” Graham v. Connor, 490 U.S. 386, 396-397, 109 S. Ct. 1865, 104 L. Ed. 2d 443 (1989). The reasonable foreseeability test would create unacceptable and unwarranted difficulties for law enforcement officers who must make quick decisions in the field, as well as for judges who would be required to determine after the fact whether the destruction of evidence in response to a knock on the door was reasonably foreseeable based on what the officers knew at the time.

Probable cause and time to secure a *879 warrant. Some courts, in applying the police-created exigency doctrine, fault law enforcement officers if, after acquiring evidence that is sufficient to establish probable cause to search particular premises, the officers do not seek a warrant but instead knock on the door and seek either to speak with an occupant or to obtain consent to search. See, e.g., Chambers, supra, at 569 (citing “[t]he failure to seek a warrant in the face of plentiful probable cause” as a factor indicating that the police deliberately created the exigency).

This approach unjustifiably interferes with legitimate law enforcement strategies. There are many entirely proper reasons why police may not want to seek a search warrant as soon as the bare minimum of evidence needed to establish probable cause is acquired. Without attempting to provide a comprehensive list of these reasons, we note a few.

First, the police may wish to speak with the occupants of a dwelling before deciding whether it is worthwhile to seek authorization for a search. They may think that a short and simple conversation may obviate the need to apply for and

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execute a warrant. See Schneckloth v. Bustamonte, 412 U.S. 218, 228, 93 S. Ct. 2041, 36 L. Ed. 2d 854 (1973). Second, the police may want to ask an occupant of the premises for consent to search because doing so is simpler, faster, and less burdensome than applying for a warrant. A consensual search also “may result in considerably less inconvenience” and embarrassment to the occupants than a search conducted pursuant to a warrant. Ibid. Third, law enforcement officers may wish to obtain more evidence before submitting what might otherwise be considered a marginal warrant application. Fourth, prosecutors may wish to wait until they acquire evidence that can justify a search that is broader in scope than the search that a judicial officer is likely to authorize based on the evidence then available. And finally, in many cases, law enforcement may not want to execute a search that will disclose the existence of an investigation because doing so may interfere with the acquisition of additional evidence against those already under suspicion or evidence about additional but as yet unknown participants in a criminal scheme.

We have said that “[l]aw enforcement officers are under no constitutional duty to call a halt to criminal investigation the moment they have the minimum evidence to establish probable cause.” Hoffa v. United States, 385 U.S. 293, 310, 87 S. Ct. 408, 17 L. Ed. 2d 374 (1966). Faulting the police for failing to apply for a search warrant at the earliest possible time after obtaining probable cause imposes a duty that is nowhere to be found in the Constitution.

Standard, or good investigative tactics. Finally, some lower court cases suggest that law enforcement officers may be found to have created or manufactured an exigency if the court concludes that the course of their investigation was “contrary to standard or good law enforcement practices (or to the policies or practices of their jurisdictions).” Gould, 364 F.3d, at 591. This approach fails to provide clear guidance for law enforcement officers and authorizes courts to make judgments on matters that are the province of those

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who are responsible for federal and state law enforcement agencies.

C

Respondent argues for a rule that *880differs from those discussed above, but his rule is also flawed. Respondent contends that law enforcement officers impermissibly create an exigency when they “engage in conduct that would cause a reasonable person to believe that entry is imminent and inevitable.” Brief for Respondent 24. In respondent’s view, relevant factors include the officers’ tone of voice in announcing their presence and the forcefulness of their knocks. But the ability of law enforcement officers to respond to an exigency cannot turn on such subtleties.

Police officers may have a very good reason to announce their presence loudly and to knock on the door with some force. A forceful knock may be necessary to alert the occupants that someone is at the door. Cf. United States v. Banks, 540 U.S. 31, 33, 124 S. Ct. 521, 157 L. Ed. 2d 343 (2003) (Police “rapped hard enough on the door to be heard by officers at the back door” and announced their presence, but defendant “was in the shower and testified that he heard nothing”). Furthermore, unless police officers identify themselves loudly enough, occupants may not know who is at their doorstep. Officers are permitted—indeed, encouraged—to identify themselves to citizens, and “in many circumstances this is cause for assurance, not discomfort.” United States v. Drayton, 536 U.S. 194, 204, 122 S. Ct. 2105, 153 L. Ed. 2d 242 (2002). Citizens who are startled by an unexpected knock on the door or by the sight of unknown persons in plain clothes on their doorstep may be relieved to learn that these persons are police officers. Others may appreciate the opportunity to make an informed decision about whether to answer the door to the police.

If respondent’s test were adopted, it would be extremely difficult for police officers to know how loudly they may announce their presence or how forcefully they may knock on a door without running afoul of the police-created exigency

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rule. And in most cases, it would be nearly impossible for a court to determine whether that threshold had been passed. The Fourth Amendment does not require the nebulous and impractical test that respondent proposes.5

D

For these reasons, we conclude that the exigent circumstances rule ap*881plies when the police do not gain entry to premises by means of an actual or threatened violation of the Fourth Amendment. This holding provides ample protection for the privacy rights that the Amendment protects.

When law enforcement officers who are not armed with a warrant knock on a door, they do no more than any private citizen might do. And whether the person who knocks on the door and requests the opportunity to speak is a police officer or a private citizen, the occupant has no obligation to

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open the door or to speak. Cf. Florida v. Royer, 460 U.S. 491, 497-498, 103 S. Ct. 1319, 75 L. Ed. 2d 229 (1983) (“[H]e may decline to listen to the questions at all and may go on his way”). When the police knock on a door but the occupants choose not to respond or to speak, “the investigation will have reached a conspicuously low point,” and the occupants “will have the kind of warning that even the most elaborate security system cannot provide.” Chambers, 395 F.3d, at 577 (Sutton, J., dissenting). And even if an occupant chooses to open the door and speak with the officers, the occupant need not allow the officers to enter the premises and may refuse to answer any questions at any time.

Occupants who choose not to stand on their constitutional rights but instead elect to attempt to destroy evidence have only themselves to blame for the warrantless exigent circumstances search that may ensue.

IV

We now apply our interpretation of the police-created exigency doctrine to the facts of this case.

A

We need not decide whether exigent circumstances existed in this case. Any warrantless entry based on exigent circumstances must, of course, be supported by a genuine exigency. See Brigham City, 547 U.S., at 406, 126 S. Ct. 1943, 164 L. Ed. 2d 650. The trial court and the Kentucky Court of Appeals found that there was a real exigency in this case, but the Kentucky Supreme Court expressed doubt on this issue, observing that there was “certainly some question as to whether the sound of persons moving [inside the apartment] was sufficient to establish that evidence was being destroyed.” 302 S.W.3d, at 655. The Kentucky Supreme Court “as-sum[ed] for the purpose of argument that exigent circumstances existed,” ibid., and it held that the police had impermissibly manufactured the exigency.

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We, too, assume for purposes of argument that an exigency existed. We decide only the question on which the Kentucky Supreme Court ruled and on which we granted certiorari: Under what circumstances do police impermissibly create an exigency? Any question about whether an exigency actually existed is better addressed by the Kentucky Supreme Court on remand. See Kirk v. Louisiana, 536 U.S. 635, 638, 122 S. Ct. 2458, 153 L. Ed. 2d 599 (2002) (per curiam) (reversing state-court judgment that exigent circumstances were not required for warrantless home entry and remanding for state court to determine whether exigent circumstances were present).

B

In this case, we see no evidence that the officers either violated the Fourth Amendment or threatened to do so prior to the point when they entered the apartment. Officer Cobb testified without contradiction that the officers *882“banged on the door as loud as [they] could” and announced either “ ‘Police, police, police’ ” or “ ‘This is the police.’ ” App. 22-23. This conduct was entirely consistent with the Fourth Amendment, and we are aware of no other evidence that might show that the officers either violated the Fourth Amendment or threatened to do so (for example, by announcing that they would break down the door if the occupants did not open the door voluntarily).

Respondent argues that the officers “demanded” entry to the apartment, but he has not pointed to any evidence in the record that supports this assertion. He relies on a passing statement made by the trial court in its opinion denying respondent’s motion to suppress. See App. to Pet. for Cert. 3a-4a. In recounting the events that preceded the search, the judge wrote that the officers “banged on the door of the apartment on the back left of the breezeway identifying themselves as police officers and demanding that the door be opened by the persons inside.” Ibid. (emphasis added and deleted). However, at a later point in this opinion, the

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judge stated that the officers “initially knock[ed] on the door of the apartment unit and await[ed] the response or consensual entry.” Id., at 9a. This later statement is consistent with the testimony at the suppression hearing and with the findings of the state appellate courts. See 302 S.W.3d, at 651 (The officers “knocked loudly on the back left apartment door and announced ‘police’ ”); App. to Pet. for Cert. 14a (The officers “knock[ed] on the door and announc[ed] themselves as police”); App. 22-24. There is no evidence of a “demand” of any sort, much less a demand that amounts to a threat to violate the Fourth Amendment. If there is contradictory evidence that has not been brought to our attention, the state court may elect to address that matter on remand.

Finally, respondent claims that the officers “explained to [the occupants that the officers] were going to make entry inside the apartment,” id., at 24, but the record is clear that the officers did not make this statement until after the exigency arose. As Officer Cobb testified, the officers “knew that there was possibly something that was going to be destroyed inside the apartment,” and “[a]t that point, . . . [they] explained . . . [that they] were going to make entry.” Ibid. (emphasis added). Given that this announcement was made after the exigency arose, it could not have created the exigency.

Like the court below, we assume for purposes of argument that an exigency existed. Because the officers in this case did not violate or threaten to violate the Fourth Amendment prior to the exigency, we hold that the exigency justified the warrantless search of the apartment.

The judgment of the Kentucky Supreme Court is reversed, and the case is remanded for further proceedings not inconsistent with this opinion.

It is so ordered.

*883SEPARATE OPINION

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Justice Ginsburg,

dissenting.

The Court today arms the police with a way routinely to dishonor the Fourth Amendment’s warrant requirement in drug cases. In lieu of presenting their evidence to a neutral magistrate, police officers may now knock, listen, then break the door down, never mind that they had ample time to obtain a warrant. I dissent from the Court’s reduction of the Fourth Amendment’s force.

The Fourth Amendment guarantees to the people “[t]he right... to be secure in their . . . houses . . . against unreasonable searches and seizures.” Warrants to search, the Amendment further instructs, shall issue only upon a showing of “probable cause” to believe criminal activity is afoot. These complementary provisions are designed to ensure that police will seek the authorization of a neutral magistrate before undertaking a search or seizure. Exceptions to the warrant requirement, this Court has explained, must be “few in number and carefully delineated,” if the main rule is to remain hardy. United States v. United States Dist. Court for Eastern Dist. of Mich., 407 U.S. 297, 318, 92 S. Ct. 2125, 32 L. Ed. 2d 752 (1972); see Kyllo v. United States, 533 U.S. 27, 31, 121 S. Ct. 2038, 150 L. Ed. 2d 94 (2001).

This case involves a principal exception to the warrant requirement, the exception applicable in “exigent circumstances.” See ante, at 460, 179 L. Ed. 2d, at 875. “[C]arefully delineated,” the exception should govern only in genuine emergency situations. Circumstances qualify as “exigent” when there is an imminent risk of death or serious in-jury, or danger that evidence will be immediately destroyed, or that a suspect will escape. Brigham City v. Stuart, 547 U.S. 398, 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650 (2006). The question presented: May police, who could pause to gain the approval of a neutral magistrate, dispense with the need to get a warrant by themselves creating exigent circumstances? I would answer no, as did the Kentucky Supreme Court. The urgency must exist, I would rule, when the police come on the scene, not subsequent to their arrival, prompted by their own conduct.

[563 U.S. 474]

I

Two pillars of our Fourth Amendment jurisprudence should have controlled the Court’s ruling: First, “whenever practical, [the police must] obtain advance judicial approval of searches and seizures through the warrant procedure,” Terry v. Ohio, 392 U.S. 1, 20, 88 S. Ct. 1868, 20 L. Ed. 2d 889 (1968); second, unwarranted “searches and seizures inside a home” bear heightened scrutiny, Payton v. New York, 445 U.S. 573, 586, 100 S. Ct. 1371, 63 L. Ed. 2d 639 (1980). The warrant requirement, Justice Jackson observed, ranks among the “fundamental distinctions between our form of government, where officers are under the law, and the police-state where they are the law.” Johnson v. United States, 333 U.S. 10, 17, 68 S. Ct. 367, 92 L. Ed. 436 (1948). The Court has accordingly declared warrantless searches, in the main, “per se unreasonable.” Mincey v. Arizona, 437 U.S. 385, 390, 98 S. Ct. 2408, 57 L. Ed. 2d 290 (1978); see also Groh v. Ramirez, 540 U.S. 551, 559, 124 S. Ct. 1284, 157 L. Ed. 2d 1068 (2004). “[T]he police bear a heavy burden,” the Court has cautioned, “when *884attempting to demonstrate an urgent need that might justify warrantless searches.” Welsh v. Wisconsin, 466 U.S. 740, 749-750, 104 S. Ct. 2091, 80 L. Ed. 2d 732 (1984).

That heavy burden has not been carried here. There was little risk that drug-related evidence would have been destroyed had the police delayed the search pending a magistrate’s authorization. As the Court recognizes, “[p]ersons in possession of valuable drugs are unlikely to destroy them unless they fear discovery by the police.” Ante, at 461, 179 L. Ed. 2d, at 876. Nothing in the record shows that, prior to the knock at the apartment door, the occupants were apprehensive about police proximity.

In no quarter does the Fourth Amendment apply with greater force than in our homes, our most private space which, for centuries, has been regarded as “ ‘entitled to special protection.’ ” Georgia v. Randolph, 547 U.S. 103, 115, and n. 4, 126 S. Ct. 1515, 164 L. Ed. 2d 208 (2006); Minnesota v. Carter, 525 U.S. 83, 99, 119 S. Ct. 469, 142 L. Ed. 2d 373 (1998) (Kennedy, J., concurring). Home intrusions, the Court has said, are indeed “the chief evil against which . . . the Fourth

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Amendment is directed.” Payton, 445 U.S., at 585, 100 S. Ct. 1371, 63 L. Ed. 2d 639 (internal quotation marks omitted); see Silverman v. United States, 365 U.S. 505, 511, 81 S. Ct. 679, 5 L. Ed. 2d 734 (1961) (“At [the Fourth Amendment’s] very core stands the right of a man to retreat to his own home and there be free from unreasonable governmental intrusion.”). “ ‘[S]earches and seizures inside a home without a warrant are [therefore] presumptively unreasonable.’ ” Brigham City, 547 U.S., at 403, 126 S. Ct. 1943, 164 L. Ed. 2d 650 (quoting Groh, 540 U.S., at 559, 124 S. Ct. 1284, 157 L. Ed. 2d 1068). How “secure” do our homes remain if police, armed with no warrant, can pound on doors at will and, on hearing sounds indicative of things moving, forcibly enter and search for evidence of unlawful activity?

II

As above noted, to justify the police activity in this case, Kentucky invoked the once-guarded exception for emergencies “in which the delay necessary to obtain a warrant. . . threaten [s] ‘the destruction of evidence.’ ” Schmerber v. California, 384 U.S. 757, 770, 86 S. Ct. 1826, 16 L. Ed. 2d 908 (1966) (quoting Preston v. United States, 376 U.S. 364, 367, 84 S. Ct. 881, 11 L. Ed. 2d 777 (1964)). To fit within this exception, “police action literally must be [taken] ‘now or never’ to preserve the evidence of the crime.” Roaden v. Kentucky, 413 U.S. 496, 505, 93 S. Ct. 2796, 37 L. Ed. 2d 757 (1973).

The existence of a genuine emergency depends not only on the state of necessity at the time of the warrant-less search; it depends, first and foremost, on “actions taken by the police preceding the warrantless search.” United States v. Coles, 437 F.3d 361, 367 (CA3 2006). See also United States v. Chambers, 395 F.3d 563, 565 (CA6 2005) (“[0]fficers must seek a warrant based on probable cause when they believe in advance they will find contraband or evidence of a crime.”). “[Wjasting a clear opportunity to obtain a warrant,” therefore, “disentitles the officer from relying on subsequent exigent circumstances.” S. Saltzburg & D. Capra, American Criminal Procedure 376 (8th ed. 2007).

Under an appropriately reined-in “emergency” or “exigent circum*885stances” exception, the result in this case should not

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be in doubt. The target of the investigation’s entry into the building, and the smell of marijuana seeping under the apartment door into the hallway, the Kentucky Supreme Court rightly determined, gave the police “probable cause . . . sufficient ... to obtain a warrant to search the ... apartment.” 302 S.W.3d 649, 653 (2010). As that court observed, nothing made it impracticable for the police to post officers on the premises while proceeding to obtain a warrant authorizing their entry. Id., at 654. Before this Court, Kentucky does not urge otherwise. See Brief for Petitioner 35, n. 13 (asserting “[i]t should be of no importance whether police could have obtained a warrant”).

In Johnson, the Court confronted this scenario: standing outside a hotel room, the police smelled burning opium and heard “some shuffling or noise” coming from the room. 333 U.S., at 12, 68 S. Ct. 367, 92 L. Ed. 436 (internal quotation marks omitted). Could the police enter the room without a warrant? The Court answered no. Explaining why, the Court said:

“The right of officers to thrust themselves into a home is ... a grave concern, not only to the individual but to a society which chooses to dwell in reasonable security and freedom from surveillance. When the right of privacy must reasonably yield to the right of search is, as a rule, to be decided by a judicial officer, not by a policeman ....

“If the officers in this case were excused from the constitutional duty of presenting their evidence to a magistrate, it is difficult to think of [any] case in which [a warrant] should be required.” Id., at 14-15, 68 S. Ct. 367, 92 L. Ed. 436.

I agree, and would not allow an expedient knock to override the warrant requirement.* Instead, I would accord that

[563 U.S. 477]

core requirement of the Fourth Amendment full respect. When possible, “a warrant must generally be secured,” the Court acknowledges. Ante, at 459, 179 L. Ed. 2d, at 874. There is every reason to conclude that securing a warrant was entirely feasible in this case, and no reason to contract the Fourth Amendment’s dominion.

Chief Justice ROBERTS delivered the opinion of the Court.

These two cases raise a common question: whether the police may, without a warrant, search digital information on a cell phone seized from an individual who has been arrested.

I

A

In the first case, petitioner David Riley was stopped by a police officer for driving with expired registration tags. In the course of the stop, the officer also learned that Riley's license had been suspended. The officer impounded Riley's car, pursuant to department policy, and another officer conducted an inventory search of the car. Riley was arrested for possession of concealed and loaded firearms when that search turned up two handguns under the car's hood. See Cal.Penal Code Ann. §§ 12025(a)(1), 12031(a)(1) (West 2009).

An officer searched Riley incident to the arrest and found items associated with the "Bloods" street gang. He also seized a cell phone from Riley's pants pocket. According to Riley's uncontradicted assertion, the phone was a "smart phone," a cell phone with a broad range of other functions based on advanced computing capability, large storage capacity, and Internet connectivity. The officer accessed information on the phone and noticed that some words (presumably in text messages or a contacts list) were preceded by the letters "CK"-a label that, he believed, stood for "Crip Killers," a slang term for members of the Bloods gang.

At the police station about two hours after the arrest, a detective specializing in gangs further examined the contents of the phone. The detective testified that he "went through" Riley's phone "looking for evidence, because ... gang members will *2481often video themselves with guns or take pictures of themselves with the guns." App. in No. 13-132, p. 20. Although there was "a lot of stuff" on the phone, particular files that "caught [the detective's] eye" included videos of young men sparring while someone yelled encouragement using the moniker "Blood." Id., at 11-13. The police also found photographs of Riley standing in front of a car they suspected had been involved in a shooting a few weeks earlier.

Riley was ultimately charged, in connection with that earlier shooting, with firing at an occupied vehicle, assault with a semiautomatic firearm, and attempted murder. The State alleged that Riley had committed those crimes for the benefit of a criminal street gang, an aggravating factor that carries an enhanced sentence. Compare Cal.Penal Code Ann. § 246 (2008) with § 186.22(b)(4)(B) (2014). Prior to trial, Riley moved to suppress all evidence that the police had obtained from his cell phone. He contended that the searches of his phone violated the Fourth Amendment, because they had been performed without a warrant and were not otherwise justified by exigent circumstances. The trial court rejected that argument. App. in No. 13-132, at 24, 26. At Riley's trial, police officers testified about the photographs and videos found on the phone, and some of the photographs were admitted into evidence. Riley was convicted on all three counts and received an enhanced sentence of 15 years to life in prison.

The California Court of Appeal affirmed. No. D059840 (Cal. App., Feb. 8, 2013), App. to Pet. for Cert. in No. 13-132, pp. 1a-23a. The court relied on the California Supreme Court's decision in People v. Diaz, 51 Cal.4th 84, 119 Cal.Rptr.3d 105, 244 P.3d 501 (2011), which held that the Fourth Amendment permits a warrantless search of cell phone data incident to an arrest, so long as the cell phone was immediately associated with the arrestee's person. See id., at 93, 119 Cal.Rptr.3d 105, 244 P.3d, at 505-506.

The California Supreme Court denied Riley's petition for review, App. to Pet. for Cert. in No. 13-132, at 24a, and we granted certiorari, 571 U.S. ----, 132 S.Ct. 94, 181 L.Ed.2d 23 (2014).

B

In the second case, a police officer performing routine surveillance observed respondent Brima Wurie make an apparent drug sale from a car. Officers subsequently arrested Wurie and took him to the police station. At the station, the officers seized two cell phones from Wurie's person. The one at issue here was a "flip phone," a kind of phone that is flipped open for use and that generally has a smaller range of features than a smart phone. Five to ten minutes after arriving at the station, the officers noticed that the phone was repeatedly receiving calls from a source identified as "my house" on the phone's external screen. A few minutes later, they opened the phone and saw a photograph of a woman and a baby set as the phone's wallpaper. They pressed one button on the phone to access its call log, then another button to determine the phone number associated with the "my house" label. They next used an online phone directory to trace that phone number to an apartment building.

When the officers went to the building, they saw Wurie's name on a mailbox and observed through a window a woman who resembled the woman in the photograph on Wurie's phone. They secured the apartment while obtaining a search warrant and, upon later executing the warrant, found and seized 215 grams of crack cocaine, marijuana, drug paraphernalia, a firearm and ammunition, and cash.

*2482Wurie was charged with distributing crack cocaine, possessing crack cocaine with intent to distribute, and being a felon in possession of a firearm and ammunition. See 18 U.S.C. § 922(g); 21 U.S.C. § 841(a). He moved to suppress the evidence obtained from the search of the apartment, arguing that it was the fruit of an unconstitutional search of his cell phone. The District Court denied the motion. 612 F.Supp.2d 104 (Mass.2009). Wurie was convicted on all three counts and sentenced to 262 months in prison.

A divided panel of the First Circuit reversed the denial of Wurie's motion to suppress and vacated Wurie's convictions for possession with intent to distribute and possession of a firearm as a felon. 728 F.3d 1 (2013). The court held that cell phones are distinct from other physical possessions that may be searched incident to arrest without a warrant, because of the amount of personal data cell phones contain and the negligible threat they pose to law enforcement interests. See id., at 8-11.

We granted certiorari. 571 U.S. ----, 134 S.Ct. 999, 187 L.Ed.2d 848 (2014).

II

The Fourth Amendment provides:

"The 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."

As the text makes clear, "the ultimate touchstone of the Fourth Amendment is 'reasonableness.' " Brigham City v. Stuart, 547 U.S. 398, 403, 126 S.Ct. 1943, 164 L.Ed.2d 650 (2006). Our cases have determined that "[w]here a search is undertaken by law enforcement officials to discover evidence of criminal wrongdoing, ... reasonableness generally requires the obtaining of a judicial warrant." Vernonia School Dist. 47J v. Acton, 515 U.S. 646, 653, 115 S.Ct. 2386, 132 L.Ed.2d 564 (1995). Such a warrant ensures that the inferences to support a search are "drawn by a neutral and detached magistrate instead of being judged by the officer engaged in the often competitive enterprise of ferreting out crime." Johnson v. United States, 333 U.S. 10, 14, 68 S.Ct. 367, 92 L.Ed. 436 (1948). In the absence of a warrant, a search is reasonable only if it falls within a specific exception to the warrant requirement. See Kentucky v. King, 563 U.S. ----, ----, 131 S.Ct. 1849, 1856-1857, 179 L.Ed.2d 865 (2011).

The two cases before us concern the reasonableness of a warrantless search incident to a lawful arrest. In 1914, this Court first acknowledged in dictum "the right on the part of the Government, always recognized under English and American law, to search the person of the accused when legally arrested to discover and seize the fruits or evidences of crime." Weeks v. United States, 232 U.S. 383, 392, 34 S.Ct. 341, 58 L.Ed. 652. Since that time, it has been well accepted that such a search constitutes an exception to the warrant requirement. Indeed, the label "exception" is something of a misnomer in this context, as warrantless searches incident to arrest occur with far greater frequency than searches conducted pursuant to a warrant. See 3 W. LaFave, Search and Seizure § 5.2(b), p. 132, and n. 15 (5th ed. 2012).

Although the existence of the exception for such searches has been recognized for a century, its scope has been debated for nearly as long. See *2483Arizona v. Gant, 556 U.S. 332, 350, 129 S.Ct. 1710, 173 L.Ed.2d 485 (2009) (noting the exception's "checkered history"). That debate has focused on the extent to which officers may search property found on or near the arrestee. Three related precedents set forth the rules governing such searches:

The first, Chimel v. California, 395 U.S. 752, 89 S.Ct. 2034, 23 L.Ed.2d 685 (1969), laid the groundwork for most of the existing search incident to arrest doctrine. Police officers in that case arrested Chimel inside his home and proceeded to search his entire three-bedroom house, including the attic and garage. In particular rooms, they also looked through the contents of drawers. Id., at 753-754, 89 S.Ct. 2034.

The Court crafted the following rule for assessing the reasonableness of a search incident to arrest:

"When an arrest is made, it is reasonable for the arresting officer to search the person arrested in order to remove any weapons that the latter might seek to use in order to resist arrest or effect his escape. Otherwise, the officer's safety might well be endangered, and the arrest itself frustrated. In addition, it is entirely reasonable for the arresting officer to search for and seize any evidence on the arrestee's person in order to prevent its concealment or destruction.... There is ample justification, therefore, for a search of the arrestee's person and the area 'within his immediate control'-construing that phrase to mean the area from within which he might gain possession of a weapon or destructible evidence." Id., at 762-763, 89 S.Ct. 2034.

The extensive warrantless search of Chimel's home did not fit within this exception, because it was not needed to protect officer safety or to preserve evidence. Id., at 763, 768, 89 S.Ct. 2034.

Four years later, in United States v. Robinson, 414 U.S. 218, 94 S.Ct. 467, 38 L.Ed.2d 427 (1973), the Court applied the Chimel analysis in the context of a search of the arrestee's person. A police officer had arrested Robinson for driving with a revoked license. The officer conducted a patdown search and felt an object that he could not identify in Robinson's coat pocket. He removed the object, which turned out to be a crumpled cigarette package, and opened it. Inside were 14 capsules of heroin. Id., at 220, 223, 89 S.Ct. 2034.

The Court of Appeals concluded that the search was unreasonable because Robinson was unlikely to have evidence of the crime of arrest on his person, and because it believed that extracting the cigarette package and opening it could not be justified as part of a protective search for weapons. This Court reversed, rejecting the notion that "case-by-case adjudication" was required to determine "whether or not there was present one of the reasons supporting the authority for a search of the person incident to a lawful arrest." Id., at 235, 89 S.Ct. 2034. As the Court explained, "[t]he authority to search the person incident to a lawful custodial arrest, while based upon the need to disarm and to discover evidence, does not depend on what a court may later decide was the probability in a particular arrest situation that weapons or evidence would in fact be found upon the person of the suspect." Ibid. Instead, a "custodial arrest of a suspect based on probable cause is a reasonable intrusion under the Fourth Amendment; that intrusion being lawful, a search incident to the arrest requires no additional justification." Ibid.

The Court thus concluded that the search of Robinson was reasonable even though there was no concern about the loss of evidence, and the arresting officer had no specific concern that Robinson might be armed. Id., at 236, 89 S.Ct. 2034.

*2484In doing so, the Court did not draw a line between a search of Robinson's person and a further examination of the cigarette pack found during that search. It merely noted that, "[h]aving in the course of a lawful search come upon the crumpled package of cigarettes, [the officer] was entitled to inspect it." Ibid. A few years later, the Court clarified that this exception was limited to "personal property ... immediately associated with the person of the arrestee." United States v. Chadwick, 433 U.S. 1, 15, 97 S.Ct. 2476, 53 L.Ed.2d 538 (1977) (200-pound, locked footlocker could not be searched incident to arrest), abrogated on other grounds by California v. Acevedo, 500 U.S. 565, 111 S.Ct. 1982, 114 L.Ed.2d 619 (1991).

The search incident to arrest trilogy concludes with Gant, which analyzed searches of an arrestee's vehicle. Gant, like Robinson, recognized that the Chimel concerns for officer safety and evidence preservation underlie the search incident to arrest exception. See 556 U.S., at 338, 129 S.Ct. 1710. As a result, the Court concluded that Chimel could authorize police to search a vehicle "only when the arrestee is unsecured and within reaching distance of the passenger compartment at the time of the search." 556 U.S., at 343, 129 S.Ct. 1710.Gant added, however, an independent exception for a warrantless search of a vehicle's passenger compartment "when it is 'reasonable to believe evidence relevant to the crime of arrest might be found in the vehicle.' " Ibid. (quoting Thornton v. United States, 541 U.S. 615, 632, 124 S.Ct. 2127, 158 L.Ed.2d 905 (2004) (SCALIA, J., concurring in judgment)). That exception stems not from Chimel, the Court explained, but from "circumstances unique to the vehicle context." 556 U.S., at 343, 129 S.Ct. 1710 .

III

These cases require us to decide how the search incident to arrest doctrine applies to modern cell phones, which are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy. A smart phone of the sort taken from Riley was unheard of ten years ago; a significant majority of American adults now own such phones. See A. Smith, Pew Research Center, Smartphone Ownership-2013 Update (June 5, 2013). Even less sophisticated phones like Wurie's, which have already faded in popularity since Wurie was arrested in 2007, have been around for less than 15 years. Both phones are based on technology nearly inconceivable just a few decades ago, when Chimel and Robinson were decided.

Absent more precise guidance from the founding era, we generally determine whether to exempt a given type of search from the warrant requirement "by assessing, on the one hand, the degree to which it intrudes upon an individual's privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests." Wyoming v. Houghton, 526 U.S. 295, 300, 119 S.Ct. 1297, 143 L.Ed.2d 408 (1999). Such a balancing of interests supported the search incident to arrest exception in Robinson, and a mechanical application of Robinson might well support the warrantless searches at issue here.

But while Robinson 's categorical rule strikes the appropriate balance in the context of physical objects, neither of its rationales has much force with respect to digital content on cell phones. On the government interest side, Robinson concluded that the two risks identified in Chimel-harm to officers and destruction of evidence-are present in all custodial *2485arrests. There are no comparable risks when the search is of digital data. In addition, Robinson regarded any privacy interests retained by an individual after arrest as significantly diminished by the fact of the arrest itself. Cell phones, however, place vast quantities of personal information literally in the hands of individuals. A search of the information on a cell phone bears little resemblance to the type of brief physical search considered in Robinson.

We therefore decline to extend Robinson to searches of data on cell phones, and hold instead that officers must generally secure a warrant before conducting such a search.

A

We first consider each Chimel concern in turn. In doing so, we do not overlook Robinson 's admonition that searches of a person incident to arrest, "while based upon the need to disarm and to discover evidence," are reasonable regardless of "the probability in a particular arrest situation that weapons or evidence would in fact be found." 414 U.S., at 235, 94 S.Ct. 467. Rather than requiring the "case-by-case adjudication" that Robinson rejected, ibid., we ask instead whether application of the search incident to arrest doctrine to this particular category of effects would "untether the rule from the justifications underlying the Chimel exception," Gant,supra, at 343, 129 S.Ct. 1710. See also Knowles v. Iowa, 525 U.S. 113, 119, 119 S.Ct. 484, 142 L.Ed.2d 492 (1998) (declining to extend Robinson to the issuance of citations, "a situation where the concern for officer safety is not present to the same extent and the concern for destruction or loss of evidence is not present at all").

1

Digital data stored on a cell phone cannot itself be used as a weapon to harm an arresting officer or to effectuate the arrestee's escape. Law enforcement officers remain free to examine the physical aspects of a phone to ensure that it will not be used as a weapon-say, to determine whether there is a razor blade hidden between the phone and its case. Once an officer has secured a phone and eliminated any potential physical threats, however, data on the phone can endanger no one.

Perhaps the same might have been said of the cigarette pack seized from Robinson's pocket. Once an officer gained control of the pack, it was unlikely that Robinson could have accessed the pack's contents. But unknown physical objects may always pose risks, no matter how slight, during the tense atmosphere of a custodial arrest. The officer in Robinson testified that he could not identify the objects in the cigarette pack but knew they were not cigarettes. See 414 U.S., at 223, 236, n. 7, 94 S.Ct. 467. Given that, a further search was a reasonable protective measure. No such unknowns exist with respect to digital data. As the First Circuit explained, the officers who searched Wurie's cell phone "knew exactly what they would find therein: data. They also knew that the data could not harm them." 728 F.3d, at 10.

The United States and California both suggest that a search of cell phone data might help ensure officer safety in more indirect ways, for example by alerting officers that confederates of the arrestee are headed to the scene. There is undoubtedly a strong government interest in warning officers about such possibilities, but neither the United States nor California offers evidence to suggest that their concerns are based on actual experience. The *2486proposed consideration would also represent a broadening of Chimel 's concern that an arrestee himself might grab a weapon and use it against an officer "to resist arrest or effect his escape." 395 U.S., at 763, 89 S.Ct. 2034. And any such threats from outside the arrest scene do not "lurk[ ] in all custodial arrests." Chadwick, 433 U.S., at 14-15, 97 S.Ct. 2476. Accordingly, the interest in protecting officer safety does not justify dispensing with the warrant requirement across the board. To the extent dangers to arresting officers may be implicated in a particular way in a particular case, they are better addressed through consideration of case-specific exceptions to the warrant requirement, such as the one for exigent circumstances. See, e.g., Warden, Md. Penitentiary v. Hayden, 387 U.S. 294, 298-299, 87 S.Ct. 1642, 18 L.Ed.2d 782 (1967) ("The Fourth Amendment does not require police officers to delay in the course of an investigation if to do so would gravely endanger their lives or the lives of others.").

2

The United States and California focus primarily on the second Chimel rationale: preventing the destruction of evidence.

Both Riley and Wurie concede that officers could have seized and secured their cell phones to prevent destruction of evidence while seeking a warrant. See Brief for Petitioner in No. 13-132, p. 20; Brief for Respondent in No. 13-212, p. 41. That is a sensible concession. See Illinois v. McArthur, 531 U.S. 326, 331-333, 121 S.Ct. 946, 148 L.Ed.2d 838 (2001); Chadwick, supra, at 13, and n. 8, 97 S.Ct. 2476. And once law enforcement officers have secured a cell phone, there is no longer any risk that the arrestee himself will be able to delete incriminating data from the phone.

The United States and California argue that information on a cell phone may nevertheless be vulnerable to two types of evidence destruction unique to digital data-remote wiping and data encryption. Remote wiping occurs when a phone, connected to a wireless network, receives a signal that erases stored data. This can happen when a third party sends a remote signal or when a phone is preprogrammed to delete data upon entering or leaving certain geographic areas (so-called "geofencing"). See Dept. of Commerce, National Institute of Standards and Technology, R. Ayers, S. Brothers, & W. Jansen, Guidelines on Mobile Device Forensics (Draft) 29, 31 (SP 800-101 Rev. 1, Sept. 2013) (hereinafter Ayers). Encryption is a security feature that some modern cell phones use in addition to password protection. When such phones lock, data becomes protected by sophisticated encryption that renders a phone all but "unbreakable" unless police know the password. Brief for United States as Amicus Curiae in No. 13-132, p. 11.

As an initial matter, these broader concerns about the loss of evidence are distinct from Chimel 's focus on a defendant who responds to arrest by trying to conceal or destroy evidence within his reach. See 395 U.S., at 763-764, 89 S.Ct. 2034. With respect to remote wiping, the Government's primary concern turns on the actions of third parties who are not present at the scene of arrest. And data encryption is even further afield. There, the Government focuses on the ordinary operation of a phone's security features, apart from any active attempt by a defendant or his associates to conceal or destroy evidence upon arrest.

We have also been given little reason to believe that either problem is prevalent. The briefing reveals only a couple of anecdotal examples of remote wiping triggered by an arrest. See Brief for Association of State Criminal Investigative Agencies et *2487al. as Amici Curiae in No. 13-132, pp. 9-10; see also Tr. of Oral Arg. in No. 13-132, p. 48. Similarly, the opportunities for officers to search a password-protected phone before data becomes encrypted are quite limited. Law enforcement officers are very unlikely to come upon such a phone in an unlocked state because most phones lock at the touch of a button or, as a default, after some very short period of inactivity. See, e.g., iPhone User Guide for iOS 7.1 Software 10 (2014) (default lock after about one minute). This may explain why the encryption argument was not made until the merits stage in this Court, and has never been considered by the Courts of Appeals.

Moreover, in situations in which an arrest might trigger a remote-wipe attempt or an officer discovers an unlocked phone, it is not clear that the ability to conduct a warrantless search would make much of a difference. The need to effect the arrest, secure the scene, and tend to other pressing matters means that law enforcement officers may well not be able to turn their attention to a cell phone right away. See Tr. of Oral Arg. in No. 13-132, at 50; see also Brief for United States as Amicus Curiae in No. 13-132, at 19. Cell phone data would be vulnerable to remote wiping from the time an individual anticipates arrest to the time any eventual search of the phone is completed, which might be at the station house hours later. Likewise, an officer who seizes a phone in an unlocked state might not be able to begin his search in the short time remaining before the phone locks and data becomes encrypted.

In any event, as to remote wiping, law enforcement is not without specific means to address the threat. Remote wiping can be fully prevented by disconnecting a phone from the network. There are at least two simple ways to do this: First, law enforcement officers can turn the phone off or remove its battery. Second, if they are concerned about encryption or other potential problems, they can leave a phone powered on and place it in an enclosure that isolates the phone from radio waves. See Ayers 30-31. Such devices are commonly called "Faraday bags," after the English scientist Michael Faraday. They are essentially sandwich bags made of aluminum foil: cheap, lightweight, and easy to use. See Brief for Criminal Law Professors as Amici Curiae 9. They may not be a complete answer to the problem, see Ayers 32, but at least for now they provide a reasonable response. In fact, a number of law enforcement agencies around the country already encourage the use of Faraday bags. See, e.g., Dept. of Justice, National Institute of Justice, Electronic Crime Scene Investigation: A Guide for First Responders 14, 32 (2d ed. Apr. 2008); Brief for Criminal Law Professors as Amici Curiae 4-6.

To the extent that law enforcement still has specific concerns about the potential loss of evidence in a particular case, there remain more targeted ways to address those concerns. If "the police are truly confronted with a 'now or never' situation,"-for example, circumstances suggesting that a defendant's phone will be the target of an imminent remote-wipe attempt-they may be able to rely on exigent circumstances to search the phone immediately. Missouri v. McNeely, 569 U.S. ----, ----, 133 S.Ct. 1552, 1561-1562, 185 L.Ed.2d 696 (2013) (quoting Roaden v. Kentucky, 413 U.S. 496, 505, 93 S.Ct. 2796, 37 L.Ed.2d 757 (1973); some internal quotation marks omitted). Or, if officers happen to seize a phone in an unlocked state, they may be able to disable a phone's automatic-lock feature in order to prevent the phone from locking and encrypting data. See App. to Reply Brief in No. 13-132, p. 3a (diagramming the few necessary steps). Such a preventive measure could *2488be analyzed under the principles set forth in our decision in McArthur, 531 U.S. 326, 121 S.Ct. 946, which approved officers' reasonable steps to secure a scene to preserve evidence while they awaited a warrant. See id., at 331-333, 121 S.Ct. 946.

B

The search incident to arrest exception rests not only on the heightened government interests at stake in a volatile arrest situation, but also on an arrestee's reduced privacy interests upon being taken into police custody. Robinson focused primarily on the first of those rationales. But it also quoted with approval then-Judge Cardozo's account of the historical basis for the search incident to arrest exception: "Search of the person becomes lawful when grounds for arrest and accusation have been discovered, and the law is in the act of subjecting the body of the accused to its physical dominion." 414 U.S., at 232, 94 S.Ct. 467 (quoting People v. Chiagles, 237 N.Y. 193, 197, 142 N.E. 583, 584 (1923)); see also 414 U.S., at 237, 94 S.Ct. 467 (Powell, J., concurring) ("an individual lawfully subjected to a custodial arrest retains no significant Fourth Amendment interest in the privacy of his person"). Put simply, a patdown of Robinson's clothing and an inspection of the cigarette pack found in his pocket constituted only minor additional intrusions compared to the substantial government authority exercised in taking Robinson into custody. See Chadwick, 433 U.S., at 16, n. 10, 97 S.Ct. 2476 (searches of a person are justified in part by "reduced expectations of privacy caused by the arrest").

The fact that an arrestee has diminished privacy interests does not mean that the Fourth Amendment falls out of the picture entirely. Not every search "is acceptable solely because a person is in custody." Maryland v. King, 569 U.S. ----, ----, 133 S.Ct. 1958, 1979, 186 L.Ed.2d 1 (2013). To the contrary, when "privacy-related concerns are weighty enough" a "search may require a warrant, notwithstanding the diminished expectations of privacy of the arrestee." Ibid. One such example, of course, is Chimel.Chimel refused to "characteriz[e] the invasion of privacy that results from a top-to-bottom search of a man's house as 'minor.' " 395 U.S., at 766-767, n. 12, 89 S.Ct. 2034. Because a search of the arrestee's entire house was a substantial invasion beyond the arrest itself, the Court concluded that a warrant was required.

Robinson is the only decision from this Court applying Chimel to a search of the contents of an item found on an arrestee's person. In an earlier case, this Court had approved a search of a zipper bag carried by an arrestee, but the Court analyzed only the validity of the arrest itself. See Draper v. United States, 358 U.S. 307, 310-311, 79 S.Ct. 329, 3 L.Ed.2d 327 (1959). Lower courts applying Robinson and Chimel, however, have approved searches of a variety of personal items carried by an arrestee. See, e.g., United States v. Carrion, 809 F.2d 1120, 1123, 1128 (C.A.5 1987) (billfold and address book); United States v. Watson, 669 F.2d 1374, 1383-1384 (C.A.11 1982) (wallet); United States v. Lee, 501 F.2d 890, 892 (C.A.D.C.1974) (purse).

The United States asserts that a search of all data stored on a cell phone is "materially indistinguishable" from searches of these sorts of physical items. Brief for United States in No. 13-212, p. 26. That is like saying a ride on horseback is materially indistinguishable from a flight to the moon. Both are ways of getting from point A to point B, but little else justifies lumping them together. Modern cell phones, as a category, implicate privacy concerns far beyond those *2489implicated by the search of a cigarette pack, a wallet, or a purse. A conclusion that inspecting the contents of an arrestee's pockets works no substantial additional intrusion on privacy beyond the arrest itself may make sense as applied to physical items, but any extension of that reasoning to digital data has to rest on its own bottom.

1

Cell phones differ in both a quantitative and a qualitative sense from other objects that might be kept on an arrestee's person. The term "cell phone" is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers.

One of the most notable distinguishing features of modern cell phones is their immense storage capacity. Before cell phones, a search of a person was limited by physical realities and tended as a general matter to constitute only a narrow intrusion on privacy. See Kerr, Foreword: Accounting for Technological Change, 36 Harv. J.L. & Pub. Pol'y 403, 404-405 (2013). Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read-nor would they have any reason to attempt to do so. And if they did, they would have to drag behind them a trunk of the sort held to require a search warrant in Chadwick,supra, rather than a container the size of the cigarette package in Robinson.

But the possible intrusion on privacy is not physically limited in the same way when it comes to cell phones. The current top-selling smart phone has a standard capacity of 16 gigabytes (and is available with up to 64 gigabytes). Sixteen gigabytes translates to millions of pages of text, thousands of pictures, or hundreds of videos. See Kerr, supra, at 404; Brief for Center for Democracy & Technology et al. as Amici Curiae 7-8. Cell phones couple that capacity with the ability to store many different types of information: Even the most basic phones that sell for less than $20 might hold photographs, picture messages, text messages, Internet browsing history, a calendar, a thousand-entry phone book, and so on. See id., at 30; United States v. Flores-Lopez, 670 F.3d 803, 806 (C.A.7 2012). We expect that the gulf between physical practicability and digital capacity will only continue to widen in the future.

The storage capacity of cell phones has several interrelated consequences for privacy. First, a cell phone collects in one place many distinct types of information-an address, a note, a prescription, a bank statement, a video-that reveal much more in combination than any isolated record. Second, a cell phone's capacity allows even just one type of information to convey far more than previously possible. The sum of an individual's private life can be reconstructed through a thousand photographs labeled with dates, locations, and descriptions; the same cannot be said of a photograph or two of loved ones tucked into a wallet. Third, the data on a phone can date back to the purchase of the phone, or even earlier. A person might carry in his pocket a slip of paper reminding him to call Mr. Jones; he would not carry a record of all his communications with Mr. Jones for the past several months, as would routinely be kept on a phone.¹

*2490Finally, there is an element of pervasiveness that characterizes cell phones but not physical records. Prior to the digital age, people did not typically carry a cache of sensitive personal information with them as they went about their day. Now it is the person who is not carrying a cell phone, with all that it contains, who is the exception. According to one poll, nearly three-quarters of smart phone users report being within five feet of their phones most of the time, with 12% admitting that they even use their phones in the shower. See Harris Interactive, 2013 Mobile Consumer Habits Study (June 2013). A decade ago police officers searching an arrestee might have occasionally stumbled across a highly personal item such as a diary. See, e.g., United States v. Frankenberry, 387 F.2d 337 (C.A.2 1967) ( per curiam ). But those discoveries were likely to be few and far between. Today, by contrast, it is no exaggeration to say that many of the more than 90% of American adults who own a cell phone keep on their person a digital record of nearly every aspect of their lives-from the mundane to the intimate. See Ontario v. Quon, 560 U.S. 746, 760, 130 S.Ct. 2619, 177 L.Ed.2d 216 (2010). Allowing the police to scrutinize such records on a routine basis is quite different from allowing them to search a personal item or two in the occasional case.

Although the data stored on a cell phone is distinguished from physical records by quantity alone, certain types of data are also qualitatively different. An Internet search and browsing history, for example, can be found on an Internet-enabled phone and could reveal an individual's private interests or concerns-perhaps a search for certain symptoms of disease, coupled with frequent visits to WebMD. Data on a cell phone can also reveal where a person has been. Historic location information is a standard feature on many smart phones and can reconstruct someone's specific movements down to the minute, not only around town but also within a particular building. See United States v. Jones, 565 U.S. ----, ----, 132 S.Ct. 945, 955, 181 L.Ed.2d 911 (2012) (SOTOMAYOR, J., concurring) ("GPS monitoring generates a precise, comprehensive record of a person's public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations.").

Mobile application software on a cell phone, or "apps," offer a range of tools for managing detailed information about all aspects of a person's life. There are apps for Democratic Party news and Republican Party news; apps for alcohol, drug, and gambling addictions; apps for sharing prayer requests; apps for tracking pregnancy symptoms; apps for planning your budget; apps for every conceivable hobby or pastime; apps for improving your romantic life. There are popular apps for buying or selling just about anything, and the records of such transactions may be accessible on the phone indefinitely. There are over a million apps available in each of the two major app stores; the phrase "there's an app for that" is now part of the popular lexicon. The average smart phone user has installed 33 apps, which together can form a revealing montage of the user's life. See Brief for Electronic Privacy Information Center as Amicus Curiae in No. 13-132, p. 9.

In 1926, Learned Hand observed (in an opinion later quoted in Chimel ) that it is "a totally different thing to search a man's *2491pockets and use against him what they contain, from ransacking his house for everything which may incriminate him." United States v. Kirschenblatt, 16 F.2d 202, 203 (C.A.2). If his pockets contain a cell phone, however, that is no longer true. Indeed, a cell phone search would typically expose to the government far more than the most exhaustive search of a house: A phone not only contains in digital form many sensitive records previously found in the home; it also contains a broad array of private information never found in a home in any form-unless the phone is.

2

To further complicate the scope of the privacy interests at stake, the data a user views on many modern cell phones may not in fact be stored on the device itself. Treating a cell phone as a container whose contents may be searched incident to an arrest is a bit strained as an initial matter. See New York v. Belton, 453 U.S. 454, 460, n. 4, 101 S.Ct. 2860, 69 L.Ed.2d 768 (1981) (describing a "container" as "any object capable of holding another object"). But the analogy crumbles entirely when a cell phone is used to access data located elsewhere, at the tap of a screen. That is what cell phones, with increasing frequency, are designed to do by taking advantage of "cloud computing." Cloud computing is the capacity of Internet-connected devices to display data stored on remote servers rather than on the device itself. Cell phone users often may not know whether particular information is stored on the device or in the cloud, and it generally makes little difference. See Brief for Electronic Privacy Information Center in No. 13-132, at 12-14, 20. Moreover, the same type of data may be stored locally on the device for one user and in the cloud for another.

The United States concedes that the search incident to arrest exception may not be stretched to cover a search of files accessed remotely-that is, a search of files stored in the cloud. See Brief for United States in No. 13-212, at 43-44. Such a search would be like finding a key in a suspect's pocket and arguing that it allowed law enforcement to unlock and search a house. But officers searching a phone's data would not typically know whether the information they are viewing was stored locally at the time of the arrest or has been pulled from the cloud.

Although the Government recognizes the problem, its proposed solutions are unclear. It suggests that officers could disconnect a phone from the network before searching the device-the very solution whose feasibility it contested with respect to the threat of remote wiping. Compare Tr. of Oral Arg. in No. 13-132, at 50-51, with Tr. of Oral Arg. in No. 13-212, pp. 13-14. Alternatively, the Government proposes that law enforcement agencies "develop protocols to address" concerns raised by cloud computing. Reply Brief in No. 13-212, pp. 14-15. Probably a good idea, but the Founders did not fight a revolution to gain the right to government agency protocols. The possibility that a search might extend well beyond papers and effects in the physical proximity of an arrestee is yet another reason that the privacy interests here dwarf those in Robinson.

C

Apart from their arguments for a direct extension of Robinson, the United States and California offer various fallback options for permitting warrantless cell phone searches under certain circumstances. Each of the proposals is flawed and contravenes our general preference to provide clear guidance to law enforcement through categorical rules. "[I]f police are to have workable rules, the balancing of the competing interests ... 'must in large part be *2492done on a categorical basis-not in an ad hoc, case-by-case fashion by individual police officers.' " Michigan v. Summers, 452 U.S. 692, 705, n. 19, 101 S.Ct. 2587, 69 L.Ed.2d 340 (1981) (quoting Dunaway v. New York, 442 U.S. 200, 219-220, 99 S.Ct. 2248, 60 L.Ed.2d 824 (1979) (White, J., concurring)).

The United States first proposes that the Gant standard be imported from the vehicle context, allowing a warrantless search of an arrestee's cell phone whenever it is reasonable to believe that the phone contains evidence of the crime of arrest. But Gant relied on "circumstances unique to the vehicle context" to endorse a search solely for the purpose of gathering evidence. 556 U.S., at 343, 129 S.Ct. 1710. Justice SCALIA's Thornton opinion, on which Gant was based, explained that those unique circumstances are "a reduced expectation of privacy" and "heightened law enforcement needs" when it comes to motor vehicles. 541 U.S., at 631, 124 S.Ct. 2127; see also Wyoming v. Houghton, 526 U.S., at 303-304, 119 S.Ct. 1297. For reasons that we have explained, cell phone searches bear neither of those characteristics.

At any rate, a Gant standard would prove no practical limit at all when it comes to cell phone searches. In the vehicle context, Gant generally protects against searches for evidence of past crimes. See 3 W. LaFave, Search and Seizure § 7.1(d), at 709, and n. 191. In the cell phone context, however, it is reasonable to expect that incriminating information will be found on a phone regardless of when the crime occurred. Similarly, in the vehicle context Gant restricts broad searches resulting from minor crimes such as traffic violations. See id., § 7.1(d), at 713, and n. 204. That would not necessarily be true for cell phones. It would be a particularly inexperienced or unimaginative law enforcement officer who could not come up with several reasons to suppose evidence of just about any crime could be found on a cell phone. Even an individual pulled over for something as basic as speeding might well have locational data dispositive of guilt on his phone. An individual pulled over for reckless driving might have evidence on the phone that shows whether he was texting while driving. The sources of potential pertinent information are virtually unlimited, so applying the Gant standard to cell phones would in effect give "police officers unbridled discretion to rummage at will among a person's private effects." 556 U.S., at 345, 129 S.Ct. 1710.

The United States also proposes a rule that would restrict the scope of a cell phone search to those areas of the phone where an officer reasonably believes that information relevant to the crime, the arrestee's identity, or officer safety will be discovered. See Brief for United States in No. 13-212, at 51-53. This approach would again impose few meaningful constraints on officers. The proposed categories would sweep in a great deal of information, and officers would not always be able to discern in advance what information would be found where.

We also reject the United States' final suggestion that officers should always be able to search a phone's call log, as they did in Wurie's case. The Government relies on Smith v. Maryland, 442 U.S. 735, 99 S.Ct. 2577, 61 L.Ed.2d 220 (1979), which held that no warrant was required to use a pen register at telephone company premises to identify numbers dialed by a particular caller. The Court in that case, however, concluded that the use of a pen register was not a "search" at all under the Fourth Amendment. See id., at 745-746, 99 S.Ct. 2577. There is no dispute here that the officers engaged in a search of Wurie's cell *2493phone. Moreover, call logs typically contain more than just phone numbers; they include any identifying information that an individual might add, such as the label "my house" in Wurie's case.

Finally, at oral argument California suggested a different limiting principle, under which officers could search cell phone data if they could have obtained the same information from a pre-digital counterpart. See Tr. of Oral Arg. in No. 13-132, at 38-43; see also Flores-Lopez, 670 F.3d, at 807 ("If police are entitled to open a pocket diary to copy the owner's address, they should be entitled to turn on a cell phone to learn its number."). But the fact that a search in the pre-digital era could have turned up a photograph or two in a wallet does not justify a search of thousands of photos in a digital gallery. The fact that someone could have tucked a paper bank statement in a pocket does not justify a search of every bank statement from the last five years. And to make matters worse, such an analogue test would allow law enforcement to search a range of items contained on a phone, even though people would be unlikely to carry such a variety of information in physical form. In Riley's case, for example, it is implausible that he would have strolled around with video tapes, photo albums, and an address book all crammed into his pockets. But because each of those items has a pre-digital analogue, police under California's proposal would be able to search a phone for all of those items-a significant diminution of privacy.

In addition, an analogue test would launch courts on a difficult line-drawing expedition to determine which digital files are comparable to physical records. Is an e-mail equivalent to a letter? Is a voicemail equivalent to a phone message slip? It is not clear how officers could make these kinds of decisions before conducting a search, or how courts would apply the proposed rule after the fact. An analogue test would "keep defendants and judges guessing for years to come." Sykes v. United States, 564 U.S. 1, ----, 131 S.Ct. 2267, 2287, 180 L.Ed.2d 60 (2011) (SCALIA, J., dissenting) (discussing the Court's analogue test under the Armed Career Criminal Act).

IV

We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime. Cell phones have become important tools in facilitating coordination and communication among members of criminal enterprises, and can provide valuable incriminating information about dangerous criminals. Privacy comes at a cost.

Our holding, of course, is not that the information on a cell phone is immune from search; it is instead that a warrant is generally required before such a search, even when a cell phone is seized incident to arrest. Our cases have historically recognized that the warrant requirement is "an important working part of our machinery of government," not merely "an inconvenience to be somehow 'weighed' against the claims of police efficiency." Coolidge v. New Hampshire, 403 U.S. 443, 481, 91 S.Ct. 2022, 29 L.Ed.2d 564 (1971). Recent technological advances similar to those discussed here have, in addition, made the process of obtaining a warrant itself more efficient. See McNeely, 569 U.S., at ----, 133 S.Ct., at 1561-1563; id., at ----, 133 S.Ct., at 1573 (ROBERTS, C.J., concurring in part and dissenting in part) (describing jurisdiction where "police officers can e-mail warrant requests to judges' iPads [and] judges have signed such warrants and e-mailed them back to officers in less than 15 minutes").

*2494Moreover, even though the search incident to arrest exception does not apply to cell phones, other case-specific exceptions may still justify a warrantless search of a particular phone. "One well-recognized exception applies when ' "the exigencies of the situation" make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment.' " Kentucky v. King, 563 U.S., at ----, 131 S.Ct., at 1856 (quoting Mincey v. Arizona, 437 U.S. 385, 394, 98 S.Ct. 2408, 57 L.Ed.2d 290 (1978)). Such exigencies could include the need to prevent the imminent destruction of evidence in individual cases, to pursue a fleeing suspect, and to assist persons who are seriously injured or are threatened with imminent injury. 563 U.S., at ----, 131 S.Ct. 1849. In Chadwick, for example, the Court held that the exception for searches incident to arrest did not justify a search of the trunk at issue, but noted that "if officers have reason to believe that luggage contains some immediately dangerous instrumentality, such as explosives, it would be foolhardy to transport it to the station house without opening the luggage." 433 U.S., at 15, n. 9, 97 S.Ct. 2476.

In light of the availability of the exigent circumstances exception, there is no reason to believe that law enforcement officers will not be able to address some of the more extreme hypotheticals that have been suggested: a suspect texting an accomplice who, it is feared, is preparing to detonate a bomb, or a child abductor who may have information about the child's location on his cell phone. The defendants here recognize-indeed, they stress-that such fact-specific threats may justify a warrantless search of cell phone data. See Reply Brief in No. 13-132, at 8-9; Brief for Respondent in No. 13-212, at 30, 41. The critical point is that, unlike the search incident to arrest exception, the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case. See McNeely, supra, at ----, 133 S.Ct., at 1559.²

Our cases have recognized that the Fourth Amendment was the founding generation's response to the reviled "general warrants" and "writs of assistance" of the colonial era, which allowed British officers to rummage through homes in an unrestrained search for evidence of criminal activity. Opposition to such searches was in fact one of the driving forces behind the Revolution itself. In 1761, the patriot James Otis delivered a speech in Boston denouncing the use of writs of assistance. A young John Adams was there, and he would later write that "[e]very man of a crowded audience appeared to me to go away, as I did, ready to take arms against writs of assistance." 10 Works of John Adams 247-248 (C. Adams ed. 1856). According to Adams, Otis's speech was "the first scene of the first act of opposition to the arbitrary claims of Great Britain. Then and there the child Independence was born." Id., at 248 (quoted in Boyd v. United States, 116 U.S. 616, 625, 6 S.Ct. 524, 29 L.Ed. 746 (1886)).

Modern cell phones are not just another technological convenience. With all they contain and all they may reveal, they hold *2495for many Americans "the privacies of life," Boyd, supra, at 630, 6 S.Ct. 524. The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought. Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple-get a warrant.

We reverse the judgment of the California Court of Appeal in No. 13-132 and remand the case for further proceedings not inconsistent with this opinion. We affirm the judgment of the First Circuit in No. 13-212.

It is so ordered.

Justice ALITO, concurring in part and concurring in the judgment.

I agree with the Court that law enforcement officers, in conducting a lawful search incident to arrest, must generally obtain a warrant before searching information stored or accessible on a cell phone. I write separately to address two points.

I

A

First, I am not convinced at this time that the ancient rule on searches incident to arrest is based exclusively (or even primarily) on the need to protect the safety of arresting officers and the need to prevent the destruction of evidence. Cf. ante, at 2484. This rule antedates the adoption of the Fourth Amendment by at least a century. See T. Clancy, The Fourth Amendment: Its History and Interpretation 340 (2008); T. Taylor, Two Studies in Constitutional Interpretation 28 (1969); Amar, Fourth Amendment First Principles, 107 Harv. L. Rev. 757, 764 (1994). In Weeks v. United States, 232 U.S. 383, 392, 34 S.Ct. 341, 58 L.Ed. 652 (1914), we held that the Fourth Amendment did not disturb this rule. See also Taylor, supra, at 45; Stuntz, The Substantive Origins of Criminal Procedure, 105 Yale L.J. 393, 401 (1995) ("The power to search incident to arrest-a search of the arrested suspect's person ...-was well established in the mid-eighteenth century, and nothing in ... the Fourth Amendment changed that"). And neither in Weeks nor in any of the authorities discussing the old common-law rule have I found any suggestion that it was based exclusively or primarily on the need to protect arresting officers or to prevent the destruction of evidence.

On the contrary, when pre-Weeks authorities discussed the basis for the rule, what was mentioned was the need to obtain probative evidence. For example, an 1839 case stated that "it is clear, and beyond doubt, that ... constables ... are entitled, upon a lawful arrest by them of one charged with treason or felony, to take and detain property found in his possession which will form material evidence in his prosecution for that crime." See Dillon v. O'Brien, 16 Cox Crim. Cas. 245, 249-251 (1887) (citing Regina, v. Frost, 9 Car. & P. 129, 173 Eng. Rep. 771). The court noted that the origins of that rule "deriv[e] from the interest which the State has in a person guilty (or reasonably believed to be guilty) of a crime being brought to justice, and in a prosecution, once commenced, being determined in due course of law." 16 Cox Crim. Cas., at 249-250. See also Holker v. Hennessey, 141 Mo. 527, 537-540, 42 S.W. 1090, 1093 (1897).

Two 19th-century treatises that this Court has previously cited in connection with the origin of the search-incident-to-arrest rule, see Weeks, supra, at 392, 34 S.Ct. 341, suggest the same rationale. See F. Wharton, Criminal Pleading and Practice § 60, p. 45 (8th ed. 1880) ("Those *2496arresting a defendant are bound to take from his person any articles which may be of use as proof in the trial of the offense with which the defendant is charged"); J. Bishop, Criminal Procedure §§ 210-212, p. 127 (2d ed. 1872) (if an arresting officer finds "about the prisoner's person, or otherwise in his possession, either goods or moneys which there is reason to believe are connected with the supposed crime as its fruits, or as the instruments with which it was committed, or as directly furnishing evidence relating to the transaction, he may take the same, and hold them to be disposed of as the court may direct").

What ultimately convinces me that the rule is not closely linked to the need for officer safety and evidence preservation is that these rationales fail to explain the rule's well-recognized scope. It has long been accepted that written items found on the person of an arrestee may be examined and used at trial.^* But once these items are taken away from an arrestee (something that obviously must be done before the items are read), there is no risk that the arrestee will destroy them. Nor is there any risk that leaving these items unread will endanger the arresting officers.

The idea that officer safety and the preservation of evidence are the sole reasons for allowing a warrantless search incident to arrest appears to derive from the Court's reasoning in Chimel v. California, 395 U.S. 752, 89 S.Ct. 2034, 23 L.Ed.2d 685 (1969), a case that involved the lawfulness of a search of the scene of an arrest, not the person of an arrestee. As I have explained, Chimel 's reasoning is questionable, see Arizona v. Gant, 556 U.S. 332, 361-363, 129 S.Ct. 1710, 173 L.Ed.2d 485 (2009) (ALITO, J., dissenting), and I think it is a mistake to allow that reasoning to affect cases like these that concern the search of the person of arrestees.

B

Despite my view on the point discussed above, I agree that we should not mechanically apply the rule used in the predigital era to the search of a cell phone. Many cell phones now in use are capable of storing and accessing a quantity of information, some highly personal, that no person would ever have had on his person in hard-copy form. This calls for a new balancing *2497of law enforcement and privacy interests.

The Court strikes this balance in favor of privacy interests with respect to all cell phones and all information found in them, and this approach leads to anomalies. For example, the Court's broad holding favors information in digital form over information in hard-copy form. Suppose that two suspects are arrested. Suspect number one has in his pocket a monthly bill for his land-line phone, and the bill lists an incriminating call to a long-distance number. He also has in his a wallet a few snapshots, and one of these is incriminating. Suspect number two has in his pocket a cell phone, the call log of which shows a call to the same incriminating number. In addition, a number of photos are stored in the memory of the cell phone, and one of these is incriminating. Under established law, the police may seize and examine the phone bill and the snapshots in the wallet without obtaining a warrant, but under the Court's holding today, the information stored in the cell phone is out.

While the Court's approach leads to anomalies, I do not see a workable alternative. Law enforcement officers need clear rules regarding searches incident to arrest, and it would take many cases and many years for the courts to develop more nuanced rules. And during that time, the nature of the electronic devices that ordinary Americans carry on their persons would continue to change.

II

This brings me to my second point. While I agree with the holding of the Court, I would reconsider the question presented here if either Congress or state legislatures, after assessing the legitimate needs of law enforcement and the privacy interests of cell phone owners, enact legislation that draws reasonable distinctions based on categories of information or perhaps other variables.

The regulation of electronic surveillance provides an instructive example. After this Court held that electronic surveillance constitutes a search even when no property interest is invaded, see Katz v. United States, 389 U.S. 347, 353-359, 88 S.Ct. 507, 19 L.Ed.2d 576 (1967), Congress responded by enacting Title III of the Omnibus Crime Control and Safe Streets Act of 1968, 82 Stat. 211. See also 18 U.S.C. § 2510 et seq. Since that time, electronic surveillance has been governed primarily, not by decisions of this Court, but by the statute, which authorizes but imposes detailed restrictions on electronic surveillance. See ibid.

Modern cell phones are of great value for both lawful and unlawful purposes. They can be used in committing many serious crimes, and they present new and difficult law enforcement problems. See Brief for United States in No. 13-212, pp. 2-3. At the same time, because of the role that these devices have come to play in contemporary life, searching their contents implicates very sensitive privacy interests that this Court is poorly positioned to understand and evaluate. Many forms of modern technology are making it easier and easier for both government and private entities to amass a wealth of information about the lives of ordinary Americans, and at the same time, many ordinary Americans are choosing to make public much information that was seldom revealed to outsiders just a few decades ago.

In light of these developments, it would be very unfortunate if privacy protection in the 21st century were left primarily to the federal courts using the blunt instrument of the Fourth Amendment. Legislatures, elected by the people, are in a better position than we are to assess and respond to the changes that have already occurred *2498and those that almost certainly will take place in the future.

I

A

In Birchfield v. North Dakota , 579 U.S. ----, 136 S.Ct. 2160, 195 L.Ed.2d 560 (2016), we recounted the country's efforts over the years to address the terrible problem of drunk driving. Today, "all States have laws that prohibit motorists from driving with a [BAC] that exceeds a specified level." Id. , at ----, 136 S.Ct., at 2166. And to help enforce BAC limits, every State has passed what are popularly called implied-consent laws. Ibid. As "a condition of the privilege of" using the public roads, these laws require that drivers submit to BAC testing "when there is sufficient reason to believe they are violating the State's drunk-driving laws." Id. , at ----, ----, 136 S.Ct., at 2166, 2169).

Wisconsin's implied-consent law is much like those of the other 49 States and the District of Columbia. It deems drivers to have consented to breath or blood tests if an officer has reason to believe they have committed one of several drug- or alcohol-related offenses.1 See Wis. Stat. §§ 343.305(2), (3). Officers seeking to conduct a BAC test must read aloud a statement declaring their intent to administer the test and advising drivers of their options and the implications of their choice. § 343.305(4). If a driver's BAC level proves too high, his license will be suspended; but if he refuses testing, his license will be revoked and his refusal may be used against him in court. See ibid . No *2532test will be administered if a driver refuses-or, as the State would put it, "withdraws" his statutorily presumed consent. But "[a] person who is unconscious or otherwise not capable of withdrawing consent is presumed not to have" withdrawn it. § 343.305(3)(b). See also §§ 343.305(3)(ar) 1-2. More than half the States have provisions like this one regarding unconscious drivers.

B

The sequence of events that gave rise to this case began when Officer Alexander Jaeger of the Sheboygan Police Department received a report that petitioner Gerald Mitchell, appearing to be very drunk, had climbed into a van and driven off. Jaeger soon found Mitchell wandering near a lake. Stumbling and slurring his words, Mitchell could hardly stand without the support of two officers. Jaeger judged a field sobriety test hopeless, if not dangerous, and gave Mitchell a preliminary breath test. It registered a BAC level of 0.24%, triple the legal limit for driving in Wisconsin. Jaeger arrested Mitchell for operating a vehicle while intoxicated and, as is standard practice, drove him to a police station for a more reliable breath test using better equipment.

On the way, Mitchell's condition continued to deteriorate-so much so that by the time the squad car had reached the station, he was too lethargic even for a breath test. Jaeger therefore drove Mitchell to a nearby hospital for a blood test; Mitchell lost consciousness on the ride over and had to be wheeled in. Even so, Jaeger read aloud to a slumped Mitchell the standard statement giving drivers a chance to refuse BAC testing. Hearing no response, Jaeger asked hospital staff to draw a blood sample. Mitchell remained unconscious while the sample was taken, and analysis of his blood showed that his BAC, about 90 minutes after his arrest, was 0.222%.

Mitchell was charged with violating two related drunk-driving provisions. See §§ 346.63(1)(a), (b). He moved to suppress the results of the blood test on the ground that it violated his Fourth Amendment right against "unreasonable searches" because it was conducted without a warrant. Wisconsin chose to rest its response on the notion that its implied-consent law (together with Mitchell's free choice to drive on its highways) rendered the blood test a consensual one, thus curing any Fourth Amendment problem. In the end, the trial court denied Mitchell's motion to suppress, and a jury found him guilty of the charged offenses. The intermediate appellate court certified two questions to the Wisconsin Supreme Court: first, whether compliance with the State's implied-consent law was sufficient to show that Mitchell's test was consistent with the Fourth Amendment and, second, whether a warrantless blood draw from an unconscious person violates the Fourth Amendment. See 2018 WI 84, ¶15, 383 Wis.2d 192, 202-203, 914 N.W.2d 151, 155-156 (2018). The Wisconsin Supreme Court affirmed Mitchell's convictions, and we granted certiorari, 586 U.S. ----, 139 S.Ct. 915, 202 L.Ed.2d 642 (2019), to decide "[w]hether a statute authorizing a blood draw from an unconscious motorist provides an exception to the Fourth Amendment warrant requirement," Pet. for Cert. ii.

II

In considering Wisconsin's implied-consent law, we do not write on a blank slate. "Our prior opinions have referred approvingly to the general concept of implied-consent laws that impose civil penalties and evidentiary consequences on motorists who refuse to comply." Birchfield , 579 U.S., at ----, 136 S.Ct., at 2185. But *2533our decisions have not rested on the idea that these laws do what their popular name might seem to suggest-that is, create actual consent to all the searches they authorize. Instead, we have based our decisions on the precedent regarding the specific constitutional claims in each case, while keeping in mind the wider regulatory scheme developed over the years to combat drunk driving. That scheme is centered on legally specified BAC limits for drivers-limits enforced by the BAC tests promoted by implied-consent laws.

Over the last 50 years, we have approved many of the defining elements of this scheme. We have held that forcing drunk-driving suspects to undergo a blood test does not violate their constitutional right against self-incrimination. See Schmerber v. California , 384 U.S. 757, 765, 86 S.Ct. 1826, 16 L.Ed.2d 908 (1966). Nor does using their refusal against them in court. See South Dakota v. Neville , 459 U.S. 553, 563, 103 S.Ct. 916, 74 L.Ed.2d 748 (1983). And punishing that refusal with automatic license revocation does not violate drivers' due process rights if they have been arrested upon probable cause, Mackey v. Montrym , 443 U.S. 1, 99 S.Ct. 2612, 61 L.Ed.2d 321 (1979) ; on the contrary, this kind of summary penalty is "unquestionably legitimate." Neville , supra , at 560, 103 S.Ct. 916.

These cases generally concerned the Fifth and Fourteenth Amendments, but motorists charged with drunk driving have also invoked the Fourth Amendment's ban on "unreasonable searches" since BAC tests are "searches." See Birchfield , 579 U.S., at ----, 136 S.Ct., at 2173. Though our precedent normally requires a warrant for a lawful search, there are well-defined exceptions to this rule. In Birchfield , we applied precedent on the "search-incident-to-arrest" exception to BAC testing of conscious drunk-driving suspects. We held that their drunk-driving arrests, taken alone, justify warrantless breath tests but not blood tests, since breath tests are less intrusive, just as informative, and (in the case of conscious suspects) readily available. Id., at ----, 136 S.Ct., at 2184-85.

We have also reviewed BAC tests under the "exigent circumstances" exception-which, as noted, allows warrantless searches "to prevent the imminent destruction of evidence." Missouri v. McNeely , 569 U.S. 141, 149, 133 S.Ct. 1552, 185 L.Ed.2d 696 (2013). In McNeely , we were asked if this exception covers BAC testing of drunk-driving suspects in light of the fact that blood-alcohol evidence is always dissipating due to "natural metabolic processes." Id. , at 152, 133 S.Ct. 1552. We answered that the fleeting quality of BAC evidence alone is not enough. Id. , at 156, 133 S.Ct. 1552. But in Schmerber it did justify a blood test of a drunk driver who had gotten into a car accident that gave police other pressing duties, for then the "further delay" caused by a warrant application really "would have threatened the destruction of evidence." McNeely , supra , at 152, 133 S.Ct. 1552 (emphasis added).

Like Schmerber , this case sits much higher than McNeely on the exigency spectrum. McNeely was about the minimum degree of urgency common to all drunk-driving cases. In Schmerber , a car accident heightened that urgency. And here Mitchell's medical condition did just the same.

Mitchell's stupor and eventual unconsciousness also deprived officials of a reasonable opportunity to administer a breath test. To be sure, Officer Jaeger managed to conduct "a preliminary breath test" using a portable machine when he first encountered Mitchell at the lake. App. to Pet.

*2534for Cert. 60a. But he had no reasonable opportunity to give Mitchell a breath test using "evidence-grade breath testing machinery." Birchfield , 579 U.S., at ----, 136 S.Ct., at 2192 (SOTOMAYOR, J., concurring in part and dissenting in part). As a result, it was reasonable for Jaeger to seek a better breath test at the station; he acted with reasonable dispatch to procure one; and when Mitchell's condition got in the way, it was reasonable for Jaeger to pursue a blood test. As Justice SOTOMAYOR explained in her partial dissent in Birchfield :

"There is a common misconception that breath tests are conducted roadside, immediately after a driver is arrested. While some preliminary testing is conducted roadside, reliability concerns with roadside tests confine their use in most circumstances to establishing probable cause for an arrest.... The standard evidentiary breath test is conducted after a motorist is arrested and transported to a police station, governmental building, or mobile testing facility where officers can access reliable, evidence-grade breath testing machinery." Id., at ----, 136 S.Ct., at 2192.

Because the "standard evidentiary breath test is conducted after a motorist is arrested and transported to a police station" or another appropriate facility, ibid. , the important question here is what officers may do when a driver's unconsciousness (or stupor) eliminates any reasonable opportunity for that kind of breath test.

III

The Fourth Amendment guards the "right of the people to be secure in their persons ... against unreasonable searches" and provides that "no Warrants shall issue, but upon probable cause." A blood draw is a search of the person, so we must determine if its administration here without a warrant was reasonable. See Birchfield , 579 U.S. at ----, 136 S.Ct., at 2174. Though we have held that a warrant is normally required, we have also "made it clear that there are exceptions to the warrant requirement." Illinois v. McArthur , 531 U.S. 326, 330, 121 S.Ct. 946, 148 L.Ed.2d 838 (2001). And under the exception for exigent circumstances, a warrantless search is allowed when " 'there is compelling need for official action and no time to secure a warrant.' " McNeely , supra , at 149, 133 S.Ct. 1552 (quoting Michigan v. Tyler , 436 U.S. 499, 509, 98 S.Ct. 1942, 56 L.Ed.2d 486 (1978) ). In McNeely , we considered how the exigent-circumstances exception applies to the broad category of cases in which a police officer has probable cause to believe that a motorist was driving under the influence of alcohol, and we do not revisit that question. Nor do we settle whether the exigent-circumstances exception covers the specific facts of this case.2 Instead, we address how the exception *2535bears on the category of cases encompassed by the question on which we granted certiorari-those involving unconscious drivers.3 In those cases, the need for a blood test is compelling, and an officer's duty to attend to more pressing needs may leave no time to seek a warrant.

A

The importance of the needs served by BAC testing is hard to overstate. The bottom line is that BAC tests are needed for enforcing laws that save lives. The specifics, in short, are these: Highway safety is critical; it is served by laws that criminalize driving with a certain BAC level; and enforcing these legal BAC limits requires efficient testing to obtain BAC evidence, which naturally dissipates. So BAC tests are crucial links in a chain on which vital interests hang. And when a breath test is unavailable to advance those aims, a blood test becomes essential. Here we add a word about each of these points.

First , highway safety is a vital public interest. For decades, we have strained our vocal chords to give adequate expression to the stakes. We have called highway safety a "compelling interest," Mackey , 443 U.S., at 19, 99 S.Ct. 2612 ; we have called it "paramount," id. , at 17, 99 S.Ct. 2612. Twice we have referred to the effects of irresponsible driving as "slaughter" comparable to the ravages of war. Breithaupt v. Abram , 352 U.S. 432, 439, 77 S.Ct. 408, 1 L.Ed.2d 448 (1957) ; Perez v. Campbell , 402 U.S. 637, 657, 672, 91 S.Ct. 1704, 29 L.Ed.2d 233 (1971) (Blackmun, J., concurring in result in part and dissenting in part). We have spoken of "carnage," Neville , 459 U.S., at 558-559, 103 S.Ct. 916, and even "frightful carnage," Tate v. Short , 401 U.S. 395, 401, 91 S.Ct. 668, 28 L.Ed.2d 130 (1971) (Blackmun, J., concurring). The frequency of preventable collisions, we have said, is "tragic," Neville , supra , at 558, 103 S.Ct. 916, and "astounding,"

*2536Breithaupt , supra , at 439, 77 S.Ct. 408. And behind this fervent language lie chilling figures, all captured in the fact that from 1982 to 2016, alcohol-related accidents took roughly 10,000 to 20,000 lives in this Nation every single year . See National Highway Traffic Safety Admin. (NHTSA), Traffic Safety Facts 2016, p. 40 (May 2018). In the best years, that would add up to more than one fatality per hour.

Second , when it comes to fighting these harms and promoting highway safety, federal and state lawmakers have long been convinced that specified BAC limits make a big difference. States resorted to these limits when earlier laws that included no "statistical definition of intoxication" proved ineffectual or hard to enforce. See Birchfield , 579 U.S., at ---- - ----, 136 S.Ct., at 2167. The maximum permissible BAC, initially set at 0.15%, was first lowered to 0.10% and then to 0.08%. Id. , at ----, ---- - ----, 136 S.Ct., at 2167, 2168-69. Congress encouraged this process by conditioning the award of federal highway funds on the establishment of a BAC limit of 0.08%, see 23 U.S. C. § 163(a) ; 23 CFR § 1225.1 (2012), and every State has adopted this limit.4 Not only that, many States, including Wisconsin, have passed laws imposing increased penalties for recidivists or for drivers with a BAC level that exceeds a higher threshold. See Wis. Stat. § 346.65(2)(am) ; Birchfield , 579 U.S., at ----, 136 S.Ct., at 2169.

There is good reason to think this strategy has worked. As we noted in Birchfield , these tougher measures corresponded with a dramatic drop in highway deaths and injuries: From the mid-1970's to the mid-1980's, "the number of annual fatalities averaged 25,000; by 2014 ..., the number had fallen to below 10,000." Id. , at ----, 136 S.Ct., at 2169.

Third , enforcing BAC limits obviously requires a test that is accurate enough to stand up in court, id. , at ---- - ----, 136 S.Ct., at 2167-68 ; see also McNeely , 569 U.S., at 159-160, 133 S.Ct. 1552 (plurality opinion). And we have recognized that "[e]xtraction of blood samples for testing is a highly effective means of" measuring "the influence of alcohol." Schmerber , 384 U.S., at 771, 86 S.Ct. 1826.

Enforcement of BAC limits also requires prompt testing because it is "a biological certainty" that "[a]lcohol dissipates from the bloodstream at a rate of 0.01 percent to 0.025 percent per hour.... Evidence is literally disappearing by the minute." McNeely , 569 U.S., at 169, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). As noted, the ephemeral nature of BAC was "essential to our holding in Schmerber ," which itself allowed a warrantless blood test for BAC. Id. , at 152, 133 S.Ct. 1552 (opinion of the Court). And even when we later held that the exigent-circumstances exception would not permit a warrantless blood draw in every drunk-driving case, we acknowledged that delays in BAC testing can "raise questions about ... accuracy." Id. , at 156, 133 S.Ct. 1552.

It is no wonder, then, that the implied-consent laws that incentivize prompt BAC testing have been with us for 65 years and now exist in all 50 States. Birchfield , supra , at ----, 136 S.Ct., at 2169. These laws and the BAC tests they require are tightly linked to a regulatory scheme that serves the most pressing of interests.

Finally, when a breath test is unavailable to promote those interests, "a blood draw becomes necessary."

*2537McNeely , 569 U.S., at 170, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). Thus, in the case of unconscious drivers, who cannot blow into a breathalyzer, blood tests are essential for achieving the compelling interests described above.

Indeed, not only is the link to pressing interests here tighter; the interests themselves are greater: Drivers who are drunk enough to pass out at the wheel or soon afterward pose a much greater risk. It would be perverse if the more wanton behavior were rewarded-if the more harrowing threat were harder to punish.

For these reasons, there clearly is a "compelling need" for a blood test of drunk-driving suspects whose condition deprives officials of a reasonable opportunity to conduct a breath test. Id., at 149, 133 S.Ct. 1552 (opinion of the Court) (internal quotation marks omitted). The only question left, under our exigency doctrine, is whether this compelling need justifies a warrantless search because there is, furthermore, " 'no time to secure a warrant.' " Ibid.

B

We held that there was no time to secure a warrant before a blood test of a drunk-driving suspect in Schmerber because the officer there could "reasonably have believed that he was confronted with an emergency, in which the delay necessary to obtain a warrant, under the circumstances, threatened the destruction of evidence." 384 U.S., at 770, 86 S.Ct. 1826 (internal quotation marks omitted). So even if the constant dissipation of BAC evidence alone does not create an exigency, see McNeely , supra , at 150-151, 133 S.Ct. 1552, Schmerber shows that it does so when combined with other pressing needs:

"We are told that [1] the percentage of alcohol in the blood begins to diminish shortly after drinking stops, as the body functions to eliminate it from the system. Particularly in a case such as this, where [2] time had to be taken to bring the accused to a hospital and to investigate the scene of the accident, there was no time to seek out a magistrate and secure a warrant. Given these special facts, we conclude that the attempt to secure evidence of blood-alcohol content in this case [without a warrant] was ... appropriate ...." 384 U.S., at 770-771, 86 S.Ct. 1826.

Thus, exigency exists when (1) BAC evidence is dissipating and (2) some other factor creates pressing health, safety, or law enforcement needs that would take priority over a warrant application. Both conditions are met when a drunk-driving suspect is unconscious, so Schmerber controls: With such suspects, too, a warrantless blood draw is lawful.

1

In Schmerber , the extra factor giving rise to urgent needs that would only add to the delay caused by a warrant application was a car accident; here it is the driver's unconsciousness. Indeed, unconsciousness does not just create pressing needs; it is itself a medical emergency.5 It means that the suspect will have to be rushed to the hospital or similar facility not just for the blood test itself but for urgent medical care.6 Police can reasonably anticipate that such a driver might require monitoring, *2538positioning, and support on the way to the hospital;7 that his blood may be drawn anyway, for diagnostic purposes, immediately on arrival;8 and that immediate medical treatment could delay (or otherwise distort the results of) a blood draw conducted later, upon receipt of a warrant, thus reducing its evidentiary value. See McNeely , supra , at 156, 133 S.Ct. 1552 (plurality opinion). All of that sets this case apart from the uncomplicated drunk-driving scenarios addressed in McNeely . Just as the ramifications of a car accident pushed Schmerber over the line into exigency, so does the condition of an unconscious driver bring his blood draw under the exception. In such a case, as in Schmerber , an officer could "reasonably have believed that he was confronted with an emergency." 384 U.S., at 770, 86 S.Ct. 1826.

Indeed, in many unconscious-driver cases, the exigency will be more acute, as elaborated in the briefing and argument in this case. A driver so drunk as to lose consciousness is quite likely to crash, especially if he passes out before managing to park. And then the accident might give officers a slew of urgent tasks beyond that of securing (and working around) medical care for the suspect. Police may have to ensure that others who are injured receive prompt medical attention; they may have to provide first aid themselves until medical personnel arrive at the scene. In some cases, they may have to deal with fatalities. They may have to preserve evidence at the scene and block or redirect traffic to prevent further accidents. These pressing matters, too, would require responsible officers to put off applying for a warrant, and that would only exacerbate the delay-and imprecision-of any subsequent BAC test.

In sum, all these rival priorities would put officers, who must often engage in a form of triage, to a dilemma. It would force them to choose between prioritizing a warrant application, to the detriment of critical health and safety needs, and delaying the warrant application, and thus the BAC test, to the detriment of its evidentiary value and all the compelling interests served by BAC limits. This is just the kind of scenario for which the exigency rule was born-just the kind of grim dilemma it lives to dissolve.

2

Mitchell objects that a warrantless search is unnecessary in cases involving unconscious drivers because warrants these days can be obtained faster and *2539more easily. But even in our age of rapid communication,

"[w]arrants inevitably take some time for police officers or prosecutors to complete and for magistrate judges to review. Telephonic and electronic warrants may still require officers to follow time-consuming formalities designed to create an adequate record, such as preparing a duplicate warrant before calling the magistrate judge.... And improvements in communications technology do not guarantee that a magistrate judge will be available when an officer needs a warrant after making a late-night arrest." McNeely , 569 U.S., at 155, 133 S.Ct. 1552.

In other words, with better technology, the time required has shrunk, but it has not disappeared. In the emergency scenarios created by unconscious drivers, forcing police to put off other tasks for even a relatively short period of time may have terrible collateral costs. That is just what it means for these situations to be emergencies.

IV

When police have probable cause to believe a person has committed a drunk-driving offense and the driver's unconsciousness or stupor requires him to be taken to the hospital or similar facility before police have a reasonable opportunity to administer a standard evidentiary breath test, they may almost always order a warrantless blood test to measure the driver's BAC without offending the Fourth Amendment. We do not rule out the possibility that in an unusual case a defendant would be able to show that his blood would not have been drawn if police had not been seeking BAC information, and that police could not have reasonably judged that a warrant application would interfere with other pressing needs or duties. Because Mitchell did not have a chance to attempt to make that showing, a remand for that purpose is necessary.

* * *

The judgment of the Supreme Court of Wisconsin is vacated, and the case is remanded for further proceedings.

It is so ordered.

Justice THOMAS, concurring in the judgment.

Today, the plurality adopts a difficult-to-administer rule: Exigent circumstances are generally present when police encounter a person suspected of drunk driving-except when they aren't. Compare ante , at 2537, with ante , at 2539. The plurality's presumption will rarely be rebutted, but it will nevertheless burden both officers and courts who must attempt to apply it. "The better (and far simpler) way to resolve" this case is to apply "the per se rule" I proposed in Missouri v. McNeely , 569 U.S. 141, 133 S.Ct. 1552, 185 L.Ed.2d 696 (2013) (dissenting opinion). Birchfield v. North Dakota , 579 U.S. ----, ----, 136 S.Ct. 2160, 2197, 195 L.Ed.2d 560 (2016) (THOMAS, J., concurring in judgment in part and dissenting in part). Under that rule, the natural metabolization of alcohol in the blood stream " 'creates an exigency once police have probable cause to believe the driver is drunk,' " regardless of whether the driver is conscious. Id., at ----, 136 S.Ct., at 2198. Because I am of the view that the Wisconsin Supreme Court should apply that rule on remand, I concur only in the judgment.

I

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." Although the Fourth Amendment does not, by its text, *2540require that searches be supported by a warrant, see Groh v. Ramirez , 540 U.S. 551, 571-573, 124 S.Ct. 1284, 157 L.Ed.2d 1068 (2004) (THOMAS, J., dissenting), "this Court has inferred that a warrant must generally be secured" for a search to comply with the Fourth Amendment, Kentucky v. King , 563 U.S. 452, 459, 131 S.Ct. 1849, 179 L.Ed.2d 865 (2011). We have also recognized, however, that this warrant presumption "may be overcome in some circumstances because '[t]he ultimate touchstone of the Fourth Amendment is "reasonableness." ' " Ibid. Accordingly, we have held that "the warrant requirement is subject to certain reasonable exceptions." Ibid.

In recent years, this Court has twice considered whether warrantless blood draws fall within an exception to the warrant requirement. First, in McNeely , a divided court held that the natural metabolization of alcohol in the bloodstream does not present a per se exigency that justifies an exception to the Fourth Amendment's warrant requirement. 569 U.S., at 145, 133 S.Ct. 1552. Then, in Birchfield , we held that blood draws may not be administered as a search incident to a lawful arrest for drunk driving. 579 U.S., at ----, 136 S.Ct., at 2184-85. The question we face in this case is whether the blood draw here fell within one of the "reasonable exceptions" to the warrant requirement.

II

The "exigent circumstances" exception applies when "the needs of law enforcement [are] so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment." King , 563 U.S., at 460, 131 S.Ct. 1849 (internal quotation marks omitted). Applying this doctrine, the Court has held that officers may conduct a warrantless search when failure to act would result in "the imminent destruction of evidence." Ibid. (internal quotation marks omitted).

As I have explained before, "the imminent destruction of evidence" is a risk in every drunk-driving arrest and thus "implicates the exigent-circumstances doctrine." McNeely , 569 U.S., at 178, 133 S.Ct. 1552. "Once police arrest a suspect for drunk driving, each passing minute eliminates probative evidence of the crime" as alcohol dissipates from the bloodstream. Id. , at 177, 133 S.Ct. 1552. In many States, this "rapid destruction of evidence," id., at 178, 133 S.Ct. 1552, is particularly problematic because the penalty for drunk driving depends in part on the driver's blood alcohol concentration, see ante , at 2536. Because the provisions of Wisconsin law at issue here allow blood draws only when the driver is suspected of impaired driving, ante , at 2531 - 2532, they fit easily within the exigency exception to the warrant requirement.

Instead of adopting this straightforward rule, the plurality makes a flawed distinction between ordinary drunk-driving cases in which blood alcohol concentration evidence "is dissipating" and those that also include "some other [pressing] factor." Ante , at 2533, 2537, 2539. But whether "some other factor creates pressing health, safety, or law-enforcement needs that would take priority over a warrant application" is irrelevant. Ante , at 2537. When police have probable cause to conclude that an individual was driving drunk, probative evidence is dissipating by the minute. And that evidence dissipates regardless of whether police had another reason to draw the driver's blood or whether "a warrant application would interfere with other pressing needs or duties." Ante , at 2539. The destruction of evidence alone is sufficient to justify a warrantless search based on exigent circumstances. See generally *2541McNeely , 569 U.S., at 176-179, 133 S.Ct. 1552 (opinion of THOMAS, J.).

Presumably, the plurality draws these lines to avoid overturning McNeely . See id. , at 156, 133 S.Ct. 1552 (majority opinion) (holding that "the natural dissipation of alcohol in the blood" does not "categorically" support a finding of exigency). But McNeely was wrongly decided, see id. , at 176-183, 133 S.Ct. 1552 (opinion of THOMAS, J.), and our decision in Birchfield has already undermined its rationale. Specifically, the Court determined in McNeely that "[t]he context of blood testing is different in critical respects from other destruction-of-evidence cases in which the police are truly confronted with a now or never situation." 569 U.S., at 153, 133 S.Ct. 1552 (majority opinion) (internal quotation marks omitted). But the Court stated in Birchfield that a distinction between "an arrestee's active destruction of evidence and the loss of evidence due to a natural process makes little sense." 579 U.S., at ----, 136 S.Ct., at 2182 ; see also ante , at 2536 - 2537. Moreover, to the extent McNeely was grounded in the belief that a per se rule was inconsistent with the "case by case," "totality of the circumstances" analysis ordinarily applied in exigent-circumstances cases, see 569 U.S., at 156, 133 S.Ct. 1552, that rationale was suspect from the start. That the exigent-circumstances exception might ordinarily require "an evaluation of the particular facts of each case," Birchfield , supra , at ----, 136 S.Ct., at 2183, does not foreclose us from recognizing that a certain, dispositive fact is always present in some categories of cases. In other words, acknowledging that destruction of evidence is at issue in every drunk-driving case does not undermine the general totality-of-the-circumstances approach that McNeely and Birchfield endorsed. Cf. ante , at 2535, n. 3.

* * *

The Court has consistently held that police officers may perform searches without a warrant when destruction of evidence is a risk. United States v. Banks , 540 U.S. 31, 38, 124 S.Ct. 521, 157 L.Ed.2d 343 (2003) ; Richards v. Wisconsin , 520 U.S. 385, 395, 117 S.Ct. 1416, 137 L.Ed.2d 615 (1997) ; Cupp v. Murphy , 412 U.S. 291, 295-296, 93 S.Ct. 2000, 36 L.Ed.2d 900 (1973) ; Schmerber v. California , 384 U.S. 757, 770-772, 86 S.Ct. 1826, 16 L.Ed.2d 908 (1966). The rule should be no different in drunk-driving cases. Because the plurality instead adopts a rule more likely to confuse than clarify, I concur only in the judgment.

Justice SOTOMAYOR, with whom Justice GINSBURG and Justice KAGAN join, dissenting.

The plurality's decision rests on the false premise that today's holding is necessary to spare law enforcement from a choice between attending to emergency situations and securing evidence used to enforce state drunk-driving laws. Not so. To be sure, drunk driving poses significant dangers that Wisconsin and other States must be able to curb. But the question here is narrow: What must police do before ordering a blood draw of a person suspected of drunk driving who has become unconscious? Under the Fourth Amendment, the answer is clear: If there is time, get a warrant.

The State of Wisconsin conceded in the state courts that it had time to get a warrant to draw Gerald Mitchell's blood, and that should be the end of the matter. Because the plurality needlessly casts aside the established protections of the warrant requirement in favor of a brand new presumption of exigent circumstances that Wisconsin does not urge, that the state courts did not consider, and that *2542contravenes this Court's precedent, I respectfully dissent.

I

In May 2013, Wisconsin police received a report that Gerald Mitchell, seemingly intoxicated, had driven away from his apartment building. A police officer later found Mitchell walking near a lake, slurring his speech and walking with difficulty. His van was parked nearby. The officer administered a preliminary breath test, which revealed a blood-alcohol concentration (BAC) of 0.24%. The officer arrested Mitchell for operating a vehicle while intoxicated.

Once at the police station, the officer placed Mitchell in a holding cell, where Mitchell began to drift into either sleep or unconsciousness. At that point, the officer decided against administering a more definitive breath test and instead took Mitchell to the hospital for a blood test. Mitchell became fully unconscious on the way. At the hospital, the officer read Mitchell a notice, required by Wisconsin's so-called "implied consent" law, which gave him the opportunity to refuse BAC testing. See Wis. Stat. § 343.305 (2016). But Mitchell was too incapacitated to respond. The officer then asked the hospital to test Mitchell's blood. Mitchell's blood was drawn about 90 minutes after his arrest, and the test revealed a BAC of 0.22%1 At no point did the officer attempt to secure a warrant.

Mitchell was charged with violating two Wisconsin drunk-driving laws. See §§ 346.63(1)(a), (b). He moved to suppress the blood-test results, arguing that the warrantless blood draw was an unreasonable search under the Fourth Amendment. In response, Wisconsin conceded that exigent circumstances did not justify the warrantless blood draw. As the State's attorney told the trial court, "There is nothing to suggest that this is a blood draw on a[n] exigent circumstances situation when there has been a concern for exigency. This is not that case." App. 134. Instead, Wisconsin argued that the warrantless blood draw was lawful because of Wisconsin's implied-consent statute. Id., at 133.

The trial court denied Mitchell's motion to suppress, and a jury convicted him of the charged offenses. On appeal, the State Court of Appeals noted that Wisconsin had "expressly disclaimed that it was relying on exigent circumstances to justify the draw," id., at 64, and that this case offered a chance to clarify the law on implied consent because the case "is not susceptible to resolution on the ground of exigent circumstances," id., at 66. The Court of Appeals then certified the appeal to the Wisconsin Supreme Court, identifying the sole issue on appeal as "whether the warrantless blood draw of an unconscious motorist pursuant to Wisconsin's implied consent law, where no exigent circumstances exist or have been argued, violates the Fourth Amendment." Id., at 61.

On certification from the state appellate court, the Supreme Court of Wisconsin upheld the search.2 The Court granted certiorari to decide whether a statute like Wisconsin's, which allows police to draw *2543blood from an unconscious drunk-driving suspect, provides an exception to the Fourth Amendment's warrant requirement.

II

The Fourth Amendment guarantees "[t]he right of the people to be secure in their persons ... against unreasonable searches and seizures." When the aim of a search is to uncover evidence of a crime, the Fourth Amendment generally requires police to obtain a warrant. Vernonia School Dist. 47J v. Acton , 515 U.S. 646, 653, 115 S.Ct. 2386, 132 L.Ed.2d 564 (1995).

The warrant requirement is not a mere formality; it ensures that necessary judgment calls are made " 'by a neutral and detached magistrate,' " not " 'by the officer engaged in the often competitive enterprise of ferreting out crime.' " Schmerber v. California , 384 U.S. 757, 770, 86 S.Ct. 1826, 16 L.Ed.2d 908 (1966). A warrant thus serves as a check against searches that violate the Fourth Amendment by ensuring that a police officer is not made the sole interpreter of the Constitution's protections. Accordingly, a search conducted without a warrant is "per se unreasonable under the Fourth Amendment-subject only to a few specifically established and well-delineated exceptions." Katz v. United States , 389 U.S. 347, 357, 88 S.Ct. 507, 19 L.Ed.2d 576 (1967) (footnote omitted); see Riley v. California , 573 U.S. 373, 382, 134 S.Ct. 2473, 189 L.Ed.2d 430 (2014) ("In the absence of a warrant, a search is reasonable only if it falls within a specific exception to the warrant requirement").

The carefully circumscribed exceptions to the warrant requirement, as relevant here, include the exigent-circumstances exception, which applies when " 'the exigencies of the situation' make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable," Kentucky v. King , 563 U.S. 452, 460, 131 S.Ct. 1849, 179 L.Ed.2d 865 (2011) (some internal quotation marks omitted); the consent exception for cases where voluntary consent is given to the search, see, e.g., Georgia v. Randolph , 547 U.S. 103, 109, 126 S.Ct. 1515, 164 L.Ed.2d 208 (2006) ; and the exception for "searches incident to arrest," see, e.g., Riley , 573 U.S., at 382, 134 S.Ct. 2473.

A

Blood draws are "searches" under the Fourth Amendment. The act of drawing a person's blood, whether or not he is unconscious, "involve[s] a compelled physical intrusion beneath [the] skin and into [a person's] veins," all for the purpose of extracting evidence for a criminal investigation. Missouri v. McNeely , 569 U.S. 141, 148, 133 S.Ct. 1552, 185 L.Ed.2d 696 (2013). The blood draw also "places in the hands of law enforcement authorities a sample that can be preserved and from which it is possible to extract information beyond a simple BAC reading," Birchfield v. North Dakota , 579 U.S. ----, ----, 136 S.Ct. 2160, 2178, 195 L.Ed.2d 560 (2016), such as whether a person is pregnant, is taking certain medications, or suffers from an illness. That "invasion of bodily integrity" disturbs "an individual's 'most personal and deep-rooted expectations of privacy.' " McNeely , 569 U.S., at 148, 133 S.Ct. 1552.

For decades, this Court has stayed true to the Fourth Amendment's warrant requirement and the narrowness of its exceptions, even in the face of attempts categorically to exempt blood testing from its protections. In Schmerber , a man was hospitalized following a car accident. 384 U.S., at 758, 86 S.Ct. 1826. At the scene of the accident and later at the hospital, a police officer noticed signs of intoxication, and he arrested Schmerber for drunk driving.

*2544Id., at 768-769, 86 S.Ct. 1826. Without obtaining a warrant, the officer ordered a blood draw to measure Schmerber's BAC, and Schmerber later challenged the blood test as an unreasonable search under the Fourth Amendment. Id., at 758-759, 86 S.Ct. 1826. The Court reinforced that search warrants are "ordinarily required ... where intrusions into the human body are concerned," id., at 770, 86 S.Ct. 1826, but it ultimately held that exigent circumstances justified the particular search at issue because certain "special facts"-namely, an unusual delay caused by the investigation at the scene and the subsequent hospital trip-left the police with "no time to seek out a magistrate and secure a warrant" before losing the evidence. Id., at 770-771, 86 S.Ct. 1826.

More recently, in McNeely , the Court held that blood tests are not categorically exempt from the warrant requirement, explaining that exigency "must be determined case by case based on the totality of the circumstances." 569 U.S., at 156, 133 S.Ct. 1552. "[T]he natural dissipation of alcohol in the blood may support a finding of exigency in a specific case," but "it does not do so categorically." Ibid . If officers "can reasonably obtain a warrant before a blood sample can be drawn without significantly undermining the efficacy of the search," the Court made clear, "the Fourth Amendment mandates that they do so." Id., at 152, 133 S.Ct. 1552 ; see id., at 167, 133 S.Ct. 1552 (ROBERTS, C.J., concurring in part and dissenting in part) ("The natural dissipation of alcohol in the bloodstream ... would qualify as an exigent circumstance, except that there may be time to secure a warrant before blood can be drawn. If there is, an officer must seek a warrant").

In Birchfield , the Court rejected another attempt categorically to exempt blood draws from the warrant requirement. 579 U.S., at ----, 136 S.Ct., at 2184. The Court considered whether warrantless breath and blood tests to determine a person's BAC level were permissible as searches incident to arrest. The Court held that warrantless breath tests were permitted because they are insufficiently intrusive to outweigh the State's need for BAC testing. See ibid. As to blood tests, however, the Court held the opposite: Because they are significantly more intrusive than breath tests, the warrant requirement applies unless particular exigent circumstances prevent officers from obtaining a warrant. Ibid. ; see id. , at ----, 136 S.Ct., at 2184 ("Nothing prevents the police from seeking a warrant for a blood test when there is sufficient time to do so in the particular circumstances or from relying on the exigent circumstances exception ... when there is not").3

B

Those cases resolve this one. Schmerber and McNeely establish that there is no categorical exigency exception for blood draws, although exigent circumstances might justify a warrantless blood draw on the facts of a particular case. And from Birchfield , we know that warrantless blood draws cannot be justified as searches incident to arrest. The lesson is straightforward: Unless there is too little time to do so, police officers must get a warrant before *2545ordering a blood draw. See 579 U.S., at ----, 136 S.Ct., at 2184 ; McNeely , 569 U.S., at 152, 133 S.Ct. 1552.

Against this precedential backdrop, Wisconsin's primary argument has always been that Mitchell consented to the blood draw through the State's "implied-consent law." Under that statute, a motorist who drives on the State's roads is "deemed" to have consented to a blood draw, breath test, and urine test, and that supposed consent allows a warrantless blood draw from an unconscious motorist as long as the police have probable cause to believe that the motorist has violated one of the State's impaired driving statutes. See Wis. Stat. § 343.305.

The plurality does not rely on the consent exception here. See ante , at 2532. With that sliver of the plurality's reasoning I agree. I would go further and hold that the state statute, however phrased, cannot itself create the actual and informed consent that the Fourth Amendment requires. See Randolph , 547 U.S., at 109, 126 S.Ct. 1515 (describing the "voluntary consent" exception to the warrant requirement as " 'jealously and carefully drawn' "); Bumper v. North Carolina , 391 U.S. 543, 548, 88 S.Ct. 1788, 20 L.Ed.2d 797 (1968) (stating that consent must be "freely and voluntarily given"); see also Schneckloth v. Bustamonte , 412 U.S. 218, 226-227, 93 S.Ct. 2041, 36 L.Ed.2d 854 (1973) (explaining that the existence of consent must "be determined from the totality of all the circumstances"). That should be the end of this case.

III

Rather than simply applying this Court's precedents to address-and reject-Wisconsin's implied-consent theory, the plurality today takes the extraordinary step of relying on an issue, exigency, that Wisconsin has affirmatively waived.4 Wisconsin has not once, in any of its briefing before this Court or the state courts, argued that exigent circumstances were present here. In fact, in the state proceedings, Wisconsin "conceded" that the exigency exception does not justify the warrantless blood draw in this case. App. 66; see 2018 WI 84, ¶12, 383 Wis.2d 192, 202, 914 N.W.2d 151, 155 ("The State expressly stated that it was not relying on exigent circumstances to justify the blood draw"). Accordingly, the state courts proceeded on the acknowledgment that no exigency is at issue here. As the Wisconsin Court of Appeals put it:

"In particular, this case is not susceptible to resolution on the ground of exigent circumstances. No testimony was received that would support the conclusion that exigent circumstances justified the warrantless blood draw. [The officer] expressed agnosticism as to how long it would have taken to obtain a warrant, and he never once testified (or even implied) that there was no time to get a warrant." App. 66.

The exigency issue is therefore waived-that is, knowingly and intentionally abandoned, *2546see Wood v. Milyard , 566 U.S. 463, 474, 132 S.Ct. 1826, 182 L.Ed.2d 733 (2012) -and the Court should not have considered it. See, e.g., Heckler v. Campbell , 461 U.S. 458, 468, n. 12, 103 S.Ct. 1952, 76 L.Ed.2d 66 (1983) ; cf. Alabama v. Shelton , 535 U.S. 654, 674, 122 S.Ct. 1764, 152 L.Ed.2d 888 (2002) ("We confine our review to the ruling the Alabama Supreme Court made in the case as presented to it").

Rather than hold Wisconsin to a concession from which it has never wavered, the plurality takes on the waived theory. As " 'a court of review, not of first view,' " however, this Court is not in the business of volunteering new rationales neither raised nor addressed below, and even less ones that no party has raised here. Timbs v. Indiana , 586 U.S. ----, ----, 139 S.Ct. 682, 690, 203 L.Ed.2d 11 (2019) ; see, e.g., Star Athletica, L. L. C. v. Varsity Brands, Inc. , 580 U.S. ----, ----, 137 S.Ct. 1002, 1009, 197 L.Ed.2d 354 (2017) ; cf. Kentucky v. Stincer , 482 U.S. 730, 747-748, n. 22, 107 S.Ct. 2658, 96 L.Ed.2d 631 (1987) (declining to review a respondent's previously unraised claim "[b]ecause the judgment [was] that of a state court" and no "exceptional" circumstances were present).

There are good reasons for this restraint. Ensuring that an issue has been fully litigated allows the Court "the benefit of developed arguments on both sides and lower court opinions squarely addressing the question." Yee v. Escondido , 503 U.S. 519, 538, 112 S.Ct. 1522, 118 L.Ed.2d 153 (1992). It also reflects a central " 'premise of our adversarial system' ": Courts sit to resolve disputes among the parties, not " 'as self-directed boards of legal inquiry and research.' " Lebron v. National Railroad Passenger Corporation , 513 U.S. 374, 408, 115 S.Ct. 961, 130 L.Ed.2d 902 (1995) (O'Connor, J., dissenting) (quoting Carducci v. Regan , 714 F.2d 171, 177 (CADC 1983) (Scalia, J.)).

These rules, in other words, beget more informed decisionmaking by the Court and ensure greater fairness to litigants, who cannot be expected to respond pre-emptively to arguments that live only in the minds of the Justices. Cf. Granite Rock Co. v. Teamsters , 561 U.S. 287, 306, and n. 14, 130 S.Ct. 2847, 177 L.Ed.2d 567 (2010) ; Yee , 503 U.S., at 535-536, 112 S.Ct. 1522. These principles should apply with greater force when the issues were not merely forfeited but affirmatively "conceded" below, App. 66, and where, as here, the question is one of constitutional dimension. The plurality acts recklessly in failing to honor these fundamental principles here.5

IV

There are good reasons why Wisconsin never asked any court to consider applying *2547any version of the exigency exception here: This Court's precedents foreclose it. According to the plurality, when the police attempt to obtain a blood sample from a person suspected of drunk driving, there will "almost always" be exigent circumstances if the person falls unconscious. Ante, at 2530. As this case demonstrates, however, the fact that a suspect fell unconscious at some point before the blood draw does not mean that there was insufficient time to get a warrant. And if the police have time to secure a warrant before the blood draw, "the Fourth Amendment mandates that they do so." McNeely , 569 U.S., at 152, 133 S.Ct. 1552. In discarding that rule for its own, the plurality may not "revisit" McNeely , ante, at 2534, but the plurality does ignore it.

A

The exigent-circumstances exception to the Fourth Amendment warrant requirement applies if the State can demonstrate a "compelling need for official action and no time to secure a warrant." Michigan v. Tyler , 436 U.S. 499, 509, 98 S.Ct. 1942, 56 L.Ed.2d 486 (1978) ; see also King , 563 U.S., at 460, 131 S.Ct. 1849 (The exception applies "when 'the exigencies of the situation' make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable" (some internal quotation marks omitted)). The Court has identified exigencies when officers need to enter a home without a warrant to provide assistance to a "seriously injured" occupant or one facing an imminent threat of such injury, Brigham City v. Stuart , 547 U.S. 398, 403, 126 S.Ct. 1943, 164 L.Ed.2d 650 (2006) ; when officers are in "hot pursuit" of a fleeing suspect, United States v. Santana , 427 U.S. 38, 42-43, 96 S.Ct. 2406, 49 L.Ed.2d 300 (1976) ; and when officers need to enter a burning building to extinguish a fire, Tyler , 436 U.S., at 509, 98 S.Ct. 1942.

Blood draws implicate a different type of exigency. The Court has "recognized that in some circumstances law enforcement officers may conduct a search without a warrant to prevent the imminent destruction of evidence." McNeely , 569 U.S., at 149, 133 S.Ct. 1552. To determine whether exigent circumstances justify a warrantless search, the Court "looks to the totality of circumstances" in the particular case. Ibid. "The critical point is that ... the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case." Riley , 573 U.S., at 402, 134 S.Ct. 2473.

In McNeely , Missouri urged the Court to adopt a categorical rule that the natural dissipation of alcohol from a person's bloodstream will always create exigent circumstances that allow police officers to order a blood draw without obtaining a warrant. 569 U.S., at 149-150, 133 S.Ct. 1552. The Court declined. Even though the gradual dissipation of a person's BAC means that "a significant delay in testing will negatively affect the probative value" of a blood test, eight Justices hewed to the traditional, "case-by-case assessment of exigency," given that police will at least in some instances have time to get a warrant. Id. , at 152, 133 S.Ct. 1552 ; see id., at 166-167, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.); id., at 175, 133 S.Ct. 1552 ("The majority answers 'It depends,' and so do I").

In that way, cases involving blood draws are "different in critical respects" from the typical destruction-of-evidence case that presents police officers with a " ' "now or never" ' " situation. Id., at 153, 133 S.Ct. 1552 (opinion of the Court). Unlike situations in which "police are just outside the door to a home" and "evidence is about to be destroyed, a person is about to be *2548injured, or a fire has broken out," some delay is inherent when officers seek a blood test regardless of whether officers are required to obtain a warrant first. Id., at 171, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.); see id., at 153, 133 S.Ct. 1552 (opinion of the Court). In the typical situation, the police cannot test a person's blood as soon as the person is arrested; police officers do not draw blood roadside. Rather, they generally must transport the drunk-driving suspect to a hospital or other medical facility and wait for a medical professional to draw the blood. That built-in delay may give police officers time to seek a warrant, especially if the suspect is brought to the hospital by an officer or emergency-response professional other than the one who applies for the warrant.

Moreover, although "the alcohol level in a person's blood begins to dissipate once the alcohol is fully absorbed," id., at 152, 133 S.Ct. 1552, it does so "over time in a gradual and relatively predictable manner," id., at 153, 133 S.Ct. 1552. Thus, even though BAC evidence is of course critical for law enforcement purposes, "the fact that the dissipation persists for some time means that the police-although they may not be able to do anything about it right away-may still be able to respond to the ongoing destruction of evidence later on." Id., at 172, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). For one, there may well be time for police officers to get a warrant before a person's BAC drops significantly. See id., at 172-173, 133 S.Ct. 1552. In addition, assuming delays do not stretch so long as to cause accuracy concerns, "experts can work backwards from the BAC at the time the sample was taken to determine the BAC at the time of the alleged offense." Id., at 156, 133 S.Ct. 1552 (opinion of the Court). Contrary to the plurality's fear mongering, in other words, a small delay to obtain a warrant is hardly a recipe for lawless roadways.

Meanwhile, as the Court has observed, significant technological advances have allowed for "more expeditious processing of warrant applications." Id., at 154, 133 S.Ct. 1552 ; see Riley , 573 U.S., at 401, 134 S.Ct. 2473. In the federal system, magistrate judges can issue warrants based on sworn testimony communicated over the phone or through " 'other reliable electronic means.' " McNeely , 569 U.S., at 154, 133 S.Ct. 1552 (quoting Fed. Rule Crim. Proc. 4.1). In a sizable majority of States, police officers can apply for warrants "remotely through various means, including telephonic or radio communication, electronic communication such as e-mail, and video conferencing." McNeely, 569 U.S., at 154, 133 S.Ct. 1552 ; see ibid. , n. 4 (collecting state statutes). And the use of "standard-form warrant applications" has streamlined the warrant process in many States as well, especially in this context. Id., at 154-155, 133 S.Ct. 1552. As a result, judges can often issue warrants in 5 to 15 minutes. Id., at 173, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). Of course, securing a warrant will always take some time, and that time will vary case to case. But "[t]here might ... be time to obtain a warrant in many cases." Id., at 172, 133 S.Ct. 1552. Thus, as McNeely made clear, the exigency exception is appropriate only in those cases in which time is not on the officer's side.

B

The reasons the Court gave for rejecting a categorical exigency exception in McNeely apply with full force when the suspected drunk driver is (or becomes) unconscious.

In these cases, there is still a period of delay during which a police officer might take steps to secure a warrant. Indeed, as the plurality observes, see ante, at 2537 - 2538, that delay is guaranteed because an unconscious person will need to be transported *2549to the hospital for medical attention. Such a delay occurred in Mitchell's case, even more so than it did in McNeely's. See McNeely , 569 U.S., at 145-146, 133 S.Ct. 1552 (explaining that the police officer transported McNeely first to the police station and then to the hospital for blood testing, taking approximately 25 minutes); App. 63-64 (explaining that the police officer arrested Mitchell, drove him to the police station, placed him in a holding cell, and then transported him to the hospital and obtained a blood sample over the course of 90 minutes).

Likewise, an unconscious person's BAC dissipates just as gradually and predictably as a conscious person's does. Furthermore, because unconsciousness is more likely to occur at higher BACs, see Martin, Measuring Acute Alcohol Impairment, in Forensic Issues in Alcohol Testing 1, 8 (S. Karch ed. 2008), the BACs of suspected drunk drivers who are unconscious will presumably be higher above the legal limit-and thus remain above the legal limit for longer-than is true for suspects who are conscious and close to sobering up. And, of course, the process for getting a warrant remains the same.

All told, the mere fact that a person is unconscious does not materially change the calculation that the Court made in McNeely when it rejected a categorical exigency exception for blood draws. In many cases, even when the suspect falls unconscious, police officers will have sufficient time to secure a warrant-meaning that the Fourth Amendment requires that they do so.

C

The plurality distinguishes unconscious drunk-driving suspects from others based on the fact that their unconsciousness means that they will, invariably, need urgent medical attention due to their loss of consciousness. See ante, at 2537 - 2538. But the need for medical care is not unique to unconscious suspects. "Drunk drivers often end up in an emergency room," whether or not they are unconscious when the police encounter them. See McNeely , 569 U.S., at 171, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). The defendant in Schmerber was hospitalized, yet the Court did not, in that case or in McNeely decades later, promulgate a categorical exception for every warrantless blood draw. That Mitchell was hospitalized is likewise insufficient here. Even if the plurality is right that every suspect who loses consciousness will need medical care, not every medical response will interfere with law enforcement's ability to secure a warrant before ordering a blood draw. See McNeely , 569 U.S., at 153-154, 133 S.Ct. 1552 ; id., at 171-172, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.).6

*2550Because the precedent is so squarely against it, the plurality devotes much of its opinion instead to painting a dire picture: the scene of a drunk-driving-related accident, where police officers must tend to the unconscious person, others who need medical attention, oncoming traffic, and investigatory needs. See ante, at 2538. There is no indication, however, in the record or elsewhere that the tableau of horribles the plurality depicts materializes in most cases. Such circumstances are certainly not present in this case, in which the police encountered Mitchell alone, after he had parked and left his car; indeed, Mitchell lost consciousness over an hour after he was found walking along the lake. The potential variation in circumstances is a good reason to decide each case on its own facts, as McNeely instructs and as the Court did in Schmerber . See McNeely , 569 U.S., at 149-151, 156, 133 S.Ct. 1552. The plurality instead bases its de facto categorical exigency exception on nothing more than a " 'considerable overgeneralization,' " id., at 153, 133 S.Ct. 1552, as well as empirical assumptions that the parties not only lacked a chance to address, but that are also belied by Wisconsin's concession in this case.7

If and when a case like the one the plurality imagines does arise, however, the police officers would not be "force[d] ... to choose between" the "rival priorities" of getting a warrant and attending to "critical health and safety needs." Ante, at 2538. Of course, the police and other first responders must dutifully attend to any urgent medical needs of the driver and any others at the scene; no one suggests that the warrant process should interfere with medical care. The point is that, in many cases, the police will have enough time to address medical needs and still get a warrant before the putative evidence (i.e., any alcohol in the suspect's blood) dissipates. And if police officers "are truly confronted with a 'now or never' situation," they will be able to rely on the exigent-circumstances exception to order the blood draw immediately. McNeely , 569 U.S., at 153, 133 S.Ct. 1552 (some internal quotation marks omitted); Riley , 573 U.S., at 391, 134 S.Ct. 2473. In any other situation, though-such as in Mitchell's and in many others-the officers can secure a warrant.

V

The Fourth Amendment, as interpreted by our precedents, requires police officers seeking to draw blood from a person suspected of drunk driving to get a warrant if possible. That rule should resolve this case.

The plurality misguidedly departs from this rule, setting forth its own convoluted counterpresumption instead. But the Fourth Amendment is not as pliable as the plurality suggests. The warrant requirement safeguards privacy and physical autonomy by "assuring citizens" that searches "are not the random or arbitrary *2551acts of government agents." Skinner v. Railway Labor Executives' Assn. , 489 U.S. 602, 621-622, 109 S.Ct. 1402, 103 L.Ed.2d 639 (1989) ; see id., at 621, 109 S.Ct. 1402.

There is no doubt that drunk drivers create grave danger on our roads. It is, however, "[p]recisely because the need for action ... is manifest" in such cases that "the need for vigilance against unconstitutional excess is great." Id., at 635, 109 S.Ct. 1402 (Marshall, J., dissenting). "Requiring a warrant whenever practicable helps ensure that when blood draws occur, they are indeed justified." McNeely , 569 U.S., at 174, 133 S.Ct. 1552 (opinion of ROBERTS, C.J.). For that reason, "the police bear a heavy burden" to justify a warrantless search like the one here based on "urgent need." Welsh v. Wisconsin , 466 U.S. 740, 749-750, 104 S.Ct. 2091, 80 L.Ed.2d 732 (1984).

The plurality today carries that burden for a State that never asked it to do so, not only here but also in a scattershot mass of future cases. Acting entirely on its own freewheeling instincts-with no briefing or decision below on the question-the plurality permits officers to order a blood draw of an unconscious person in all but the rarest cases, even when there is ample time to obtain a warrant. The plurality may believe it is helping to ameliorate the scourge of drunk driving, but what it really does is to strike another needless blow at the protections guaranteed by the Fourth Amendment. With respect, I dissent.

Justice GORSUCH, dissenting.

We took this case to decide whether Wisconsin drivers impliedly consent to blood alcohol tests thanks to a state statute. That law says that anyone driving in Wisconsin agrees-by the very act of driving-to testing under certain circumstances. But the Court today declines to answer the question presented. Instead, it upholds Wisconsin's law on an entirely different ground-citing the exigent circumstances doctrine. While I do not doubt that the Court may affirm for any reason supported by the record, the application of the exigent circumstances doctrine in this area poses complex and difficult questions that neither the parties nor the courts below discussed. Rather than proceeding solely by self-direction, I would have dismissed this case as improvidently granted and waited for a case presenting the exigent circumstances question.