Rule 703 Federal Rules of Evidence

Rule 703 of the Federal Rules of Evidence is about Bases of an Expert. It is under Article VII (Opinions and Expert Testimony) of the Rules.

An expert may base an opinion on facts or data in the case that the expert has been made aware of 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. But if the facts or data would otherwise be inadmissible, the proponent of the opinion may disclose them to the jury only if their probative value in helping the jury evaluate the opinion substantially outweighs their prejudicial effect.