Also known as: Fed. R. Evid. 703 · Federal Rule of Evidence 703 · FRE703 · Rule 703 · FRE Rule 703
Written by attorneys · grounded in primary & secondary sources — see below
A rule of evidence that permits an expert to 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, the facts or data need not be admissible for the opinion to be admitted.
Falcon Dynamics hired an aerospace engineer to opine on whether a competitor's design infringed its patent. The engineer reviewed technical specifications supplied by counsel and market reports from third parties without personally inspecting any prototypes. The court allowed the opinion because experts in the field routinely rely on such materials even when the underlying documents would be inadmissible hearsay.
In a criminal prosecution, the prosecution called a forensic analyst to testify that a DNA profile from the crime scene matched the defendant's profile. The analyst had not performed the testing herself but had reviewed a report prepared by another laboratory. The court permitted the opinion because analysts in the field customarily rely on such reports to reach conclusions about profile matches.
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Yes. Under FRE 703 an expert may base an opinion on facts or data that experts in the field would reasonably rely on even if those facts or data are themselves inadmissible, provided the probative value of disclosing them is not substantially outweighed by the danger of unfair prejudice.
An expert may rely on three categories of information: facts personally observed, facts presented at trial such as through a hypothetical question, and facts made known to the expert outside the courtroom, so long as the information is of a type reasonably relied upon by experts in the field.
Only if the court determines that their probative value in helping the jury evaluate the opinion substantially outweighs their prejudicial effect. Otherwise the expert may rely on the facts internally but may not disclose them to the jury.
Rule 602 expressly states that its personal-knowledge requirement does not apply to expert testimony offered under Rule 703. An expert therefore may offer an opinion based on facts the expert did not personally observe.
…opinion are not introduced for a plausible nonhearsay purpose”). This view is directly contrary to the current version of Rule 703 of the Federal Rules of Evidence, which this Court approved and sent to Congress in 2000. Under that Rule, “basis evidence” that is not admissible for its truth may be disclosed even in a…