Law Enforcement Expert's Medical Opinions Excluded

Plaintiff Taneysha Carter alleged excessive force arising from a July 7, 2022 officer-involved shooting at Mesa Police Department headquarters.

Defendants Officer Drew Lawrence and City of Mesa sought to exclude all expert testimony and opinions of Plaintiff's police practices expert Roger Clark under Federal Rule of Evidence 702 and Daubert.

Law Enforcement Expert Witness

Roger Alma Clark is a retired law enforcement professional with 27 years of experience in the Los Angeles County Sheriff’s Department (LASD). He was hired on December 1, 1965, and served until his retirement on March 31, 1993. Throughout his distinguished career, he held several key positions, including six years as a Deputy Sheriff, six years as a Sergeant, and 15 years as a Lieutenant. Roger retired with a California Peace Officer Standards and Training (POST) Advanced Certificate and is a graduate of the POST Command College, class #5, 1988.

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Discussion by the Court

Defendants raised objections to the admissibility of Clark's testimony. They challenged Clark's qualifications, the factual bases of his opinions, his methodology, and the helpfulness of his opinions to the trier of fact.

While Clark may possess specialized experience and knowledge in the area of police practices, that does not license him to assert legal conclusions, make credibility determinations, comment on subjective mental states, or provide medical opinions.

Having carefully considered Clark's expert report and Defendants' challenges, the Court found that Clark's stated opinions are so mired with deficiencies as to render his opinions completely unreliable and inadmissible in their entirety.

The most egregious deficiencies in Clark's report stem from his assertions of legal conclusions. While he does comment on the applicability of police training and standards, that commentary is couched in legal deductions.

Clark's report is littered with judicially defined and legally specialized terms. Most notably, Clark stated that Lawrence's use of force was "excessive," and he opined on what "no reasonable officer" would believe. In assessing Carter's excessive force claims, the jury will have to determine whether Lawrence's use of force was objectively reasonable. Clark's statements on what conduct is objectively reasonable and excessive thus has "a specialized meaning in law" and constitutes legal conclusions. Such legal conclusions are inadmissible.

Clark's report makes determinations as to credibility and casts judgment on competing evidence, often without any apparent factual basis. For example, while the parties dispute the nature of the collision between Carter and Lawrence's vehicles, Clark's report and testimony confirm his unwavering opinion that the contact was "brief" and "fairly minimal." Clark makes this assertion while disregarding contradictory evidence and without any expertise in accident reconstruction. When asked why he did not find Lawrence's account credible, Clark admitted that he made his determination without "the black box of the patrol car"—a recorder that logs crash data—"to show whether Lawrence was on the gas or on the brake." Such determinations are inadmissible because "jurors are more than capable of drawing their own conclusions about the evidence presented without the benefit of [an expert's] personal interpretation of it."

The final deficiency the Court will note is Clark's improper offering of opinions on mental states and medical opinions. An expert may not opine on the mental states of individuals. Clark's medical opinions and commentary on mental states are inadmissible, and these contentions are prevalent throughout his report.

Held

The Court granted the Defendants' motion to exclude the opinions of Roger Clark.

Key Takeaway

An expert witness cannot give an opinion as to their legal conclusion, i.e., an opinion on an ultimate issue of law. Courts have held that an expert's use of 'judicially defined' and 'legally specialized' terms constitutes an expression of opinion on an ultimate issue of law.

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