United States District Court for the Western District of Washington Finds Experts Can't Testify About Use of Appropriate Force in Excessive Force Case

Federal Rule of Evidence 704(a) states that

An opinion is not objectionable just because it embraces an ultimate issue.

That said, while experts are allowed to render opinions on ultimate factual issues, they are not allowed to render opinions that constitute legal conclusions and invade the province of the jury. A good example of this latter type of opinion testimony can be found in the recent opinion of the United States District Court for the Western District of Washington in Bao Xuyen Le v. Reverend Dr. Martin Luther King, Jr. County, 2019 WL 2289681 (W.D.Wash. 2019).

Bao Xuyen Le involves an excessive force claim, and the court concluded that

Defendant King County’s expert James Borden and plaintiffs' experts William Harmening and Scott DeFoe will not be permitted to testify at trial concerning whether or not King County Deputy Sheriff Cesar Molina used lawful, reasonable, justified, or appropriate force when he shot Tommy Le on June 14, 2017. Although the Federal Rules of Evidence do not preclude an expert from opining about an ultimate issue,...the Court may bar such testimony when it is not helpful to the jury...or when it might be unduly prejudicial....The Court concludes that the issue of whether or not the force used by Deputy Molina was excessive is properly within the province of the jury, and that expert testimony will not assist the jury in making this determination....[S]ee...Shannon v. Koehler, 2011 WL 10483363 at *29-*30 (N.D. Iowa Sep. 16, 2011) (reasoning that an expert’s opinion concerning the reasonableness of an officer’s conduct is a legal conclusion, not a fact-based opinion that might assist the jury)....In addition, the experts will not be permitted to opine about which version of events is more credible or which facts actually occurred, they may not speculate about the intent, motive, or state of mind of anyone involved, including Tommy Le and Deputy Molina, and they may not testify about the law concerning the use of force. See Fed.R.Evid. 704 advisory committee’s note to 1972 proposed rule (these provisions protect against “the admission of opinions which would merely tell the jury what result to reach”).

-CM