Witness with Proper Knowledge

OVERVIEW: Process of Admissibility and Governing Statutes:

1) Witness With Proper Knowledge 2)Accurately Reports 3) Lawfully Obtained Evidence 4) That is Relevant.

Rule 602. Need for Personal Knowledge 
A witness may testify to a matter only if evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may consist of the witness’s own testimony. This rule does not apply to a witness’s expert testimony under Rule 703.

Rule 701. Opinion Testimony by Lay Witnesses
If a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that is:
(a) rationally based on the witness's perception; and
(b) helpful to clearly understanding the witness's testimony or to determining a fact in issue.

Rule 702. Testimony by Expert Witness
A witness who is qualified as an expert by knowledge, skill, experience, training or education may testify in the form of an opinion or otherwise if the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue.

Rule 703. Bases of an Expert's Opinion Testimony
An expert may base an opinion on facts or data in the case that the expert has been made aware of, reviewed, or personally observed. If experts in the particular field would reasonably rely on those kinds of facts or data in forming an opinion on the subject, they need not be admissible for the opinion to be admitted.

Rule 602 instructs us that there are two types of witnesses: 1) Non-expert witnesses or those with personal knowledge (Rule 602) and/or 2) Expert witnesses (Rule 702). In ths section, we will discuss each type in turn, and how the foundation for this first step in our 4-step process of admissibility is the same for both. It is important to note that the two different types of witnesses are not mutually exclusive because a witness can be both; the subject matter of their testimony will determine their status as one or the other. Take a forensic pathologist for example. They don’t need to be an expert to authenticate photographs from the autopsy so long as the testimony establishes they personally observed the objects depicted in them, though they would need to be an expert to offer their opinion as to how the objects depicted in those photographs illustrate the complainant’s cause of death. In both lines of questioning, the proponent must establish that the witness has the proper basis of knowledge to share their testimony with the jury.