Testimony by Expert Witnesses

U.S Code last checked for updates: Dec 12, 2025

Rule 702.

(a)

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;

(b)

the testimony is based on sufficient facts or data;

(c)

the testimony is the product of reliable principles and methods; and

(d)

the expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.

(Pub. L. 93–595, § 1, Jan. 2, 1975, 88 Stat. 1937; Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 26, 2011, eff. Dec. 1, 2011; Apr. 24, 2023, eff. Dec. 1, 2023.)