February 02, 2016 Practice Points

How to Distinguish Lay and Expert Witness Testimony

Why does the distinction matter?

By Maria L. Kreiter

When testimony is “expert” in nature, it must comport with the stringent standards articulated by the U.S. Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). However, the distinction between lay opinions and expert testimony is not a bright line. Courts throughout the country have come to different conclusions about the scope of permissible lay opinions and what constitutes expert testimony. This article discusses the distinctions between lay witness testimony and expert testimony.

Why Does the Distinction Matter?
As an initial matter, one critical issue lawyers must consider when assessing whether reliance on lay or expert opinions will be necessary is the disclosure requirements in Federal Rule of Civil Procedure 26(a)(2) that apply to expert testimony. Rule 26(a)(2) requires expert reports from retained experts. Conversely, lay witness opinions typically need not be disclosed in advance of trial or supported by formal reports. However, given the fine line some courts draw between lay witness opinions and expert testimony, lawyers must review the authority in their particular jurisdiction early in the case.

To avoid any uncertainty, attorneys should consider either disclosing lay witness opinions or pursuing an agreement with opposing counsel as to the exact nature of the disclosures required for specific testimony to be elicited in the case. Such disclosures or agreements will ensure that important testimony that counsel hopes to rely on is not excluded on the eve of trial.

The Applicable Federal Rules
The Federal Rules of Evidence governing lay opinions and expert testimony—rules 701 and 702 respectively—set forth the standards for admissibility of both categories of evidence.

Under rule 701, a lay witness may provide an opinion that is (1) rationally based on the witness’s perception; (2) helpful to clearly understanding the witness’s testimony or to determining a fact in issue; and (3) not based on scientific, technical, or other specialized knowledge within the scope of rule 702.

Expert testimony, in contrast, is only permissible if a witness is “qualified as an expert by knowledge, skill, experience, training, or education” and the proffered testimony meets four requirements: (1) 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; (2) the testimony is based on sufficient facts or data; (3) the testimony is the product of reliable principles and methods; and (4) the expert has reliably applied the principles and methods to the facts of the case. Experts may testify “in the form of an opinion or otherwise”—it is entirely appropriate for an expert to testify generally about principles, methods, or other information and leave the ultimate inference or “opinion” to the finder of fact.

Treatment by the Federal Circuit Courts
Federal circuit courts have come to different conclusions regarding the scope of permissible lay opinion testimony. Some courts take a broad view of lay witness opinions. For example, in U.S. v. Jayyousi, 657 F.3d 1085 (11th Cir. 2011), the Eleventh Circuit permitted an FBI agent to testify as to the meaning of alleged code words used between codefendants, even though the calls were predominantly in Arabic and the agent did not speak the language. Id. at 1101–1104. Taking a narrower view of rule 701, the Sixth Circuit reached a different result in a case involving similar facts. In U.S. v. Freeman, 730 F.3d 590 (6th Cir. 2013), the Sixth Circuit reversed and remanded a trial court’s decision to permit an FBI agent’s lay witness testimony interpreting phone calls between codefendants. The agent had provided voice identifications and substantive interpretations of the meaning of various statements contained in the calls. Id. at 594. The court focused on the fact that the agent lacked first-hand knowledge sufficient to lay a foundation for a lay witness opinion under rule 701(a).

Need for Early Assessment
Given the nuance between lay and expert testimony, an early assessment of what, if any, opinions witnesses may offer at trial is critical. Similarly, an understanding of how your particular court interprets the scope and requirements for lay opinions and expert witness testimony is essential when developing your case strategy.

Keywords: litigation, business torts, unfair competition, lay witness, expert witness, witness testimony

Maria Kreiter is a shareholder with Godfrey & Kahn in Milwaukee, Wisconsin.


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Maria L. Kreiter – February 2, 2016