Federal Rule of Evidence 701 states: If the witness is not testifying as an expert, the witness' testimony in the form of opinions or inferences is limited to those opinions or inferences which are (a) rationally based on the perception of the witness and (b) helpful to a clear understanding of the witness' testimony or the determination of a fact in issue.
If the evidence meets the firsthand knowledge requirement of Rule 701(a), the eyewitness' opinion was admissible if it would help the jury to resolve a disputed fact. The 'modern trend favors admissibility of opinion testimony.' Leo, 941 F.2d at 193 (quoting Teen-Ed, Inc. v. Kimball Int'l, Inc., 620 F.2d 399, 403 (3d Cir. 1980)). The relaxation of the standards governing the admissibility of opinion testimony relies on cross-examination to reveal any weaknesses in the witness' conclusions. Fed. R. Evid. 701(b) advisory committee's note. If circumstances can be presented with greater clarity by stating an opinion, then that opinion is helpful to the trier of fact. See United States v. Skeet, 665 F.2d 983, 985 (9th Cir. 1982). Allowing witnesses to state their opinions instead of describing all of their observations has the further benefit ...