1 Ohlbaum on the Pennsylvania Rules of Evidence § 702.08

Summary

• [1] In General

  Expert testimony has been permitted only when the subject matter is distinctly related to a science, skill, or occupation beyond the understanding, knowledge, or experience of the average layperson [Commonwealth v. Jones, 240 A.3d 881 (Pa. 2020), Grady v. Frito-Lay, 839 A.2d 1038 (Pa. 2003)]. Rule 702 provides that an expert who is qualified by the type of knowledge or experience beyond the knowledge or experience of laypersons may state an opinion if it “will help the trier of fact to understand the evidence or to determine a fact in issue.” Pa.R.E. 702.

  Pennsylvania courts have barred expert testimony involving matters that are not beyond laypersons’ knowledge by finding that such opinions do not assist the jury. For example, traditionally the Pennsylvania Supreme Court did not permit expert testimony on issues of credibility or the reliability of eyewitnesses. [see Commonwealth v. Simmons, 662 A.2d 621 (Pa. 1995), overruled, in part, by Commonwealth v. Walker, 92 A.3d ...