What a police practices expert
actually does.

A police practices expert answers one family of questions: did the police conduct documented in this record follow national standards, the agency’s own policy, the officers’ training, and generally accepted police practices? The raw material is the record counsel assembles: video, incident and investigation reports, witness statements, depositions, training files and agency policy. The yardstick is external to the case: what accepted practice required of an officer in that situation, judged on the totality of the facts and circumstances.

The standards are not the expert’s private preferences. Generally accepted police practices are informed by the national bodies and materials agencies themselves rely on: IACP model policies, PERF guidance, CALEA accreditation standards, state POST commissions, and the curricula of agency academies, field training programs and in-service instruction. An opinion grounded there can be checked against something outside the expert’s own experience, which is precisely what makes it useful to counsel and durable in front of a jury.

Use-of-force questions are governed by Graham v. Connor, 490 U.S. 386 (1989), and the analysis holds to that discipline: objective reasonableness judged from what was known at the time, with no hindsight. Where the record shows the officer’s conduct fell within accepted practices, the report says so. The analysis does not change with the party who retains it.

The sequence is the same in every engagement. Retention is confirmed in writing, the complete record arrives on physical media, and the analysis starts from the video and the paper, not from the complaint or the press coverage. Each item in the record is read against the others: the written reports against the video, the statements against the timeline, the conduct against the policy and training that were in force on the date of the incident.

The opinions that survive that process go into a written report that states each opinion and its basis, identifies the materials considered, and stays inside the discipline. Where the record supports the officers, the report says so. Where it does not, the report says that, in the same measured terms. The report is written to be defended: at deposition, under Fed. R. Evid. 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and at trial.

Method is also why the practice declines hindsight. The analysis is anchored, per Graham, to what was known at the time: the question is never what the incident looks like with the ending known, but what generally accepted police practices required of an officer seeing what this officer saw, knowing what this officer knew.

A police practices opinion often sits inside a larger expert lineup, and a clean division of labor strengthens every seat in it. Questions of injury, cause of death and medical causation belong to qualified medical experts; laboratory and firearms evidence belongs to the forensic disciplines; each is deferred to on the record where the case raises them.

What this practice does not do is offer those lanes. The discipline stays police practices: standards, policy, training and conduct. When a report reaches the edge of another expertise, it says so and stops. Attorneys who depose experts for a living know why that matters: an expert who exceeds his discipline gets impeached with his own report, and the damage spreads to every opinion in it.

For matters that call for a second discipline, independent consultants are retained case-by-case, each reviewing the record independently within his own discipline: Sheriff Robert Snaza on command, policy and training, and FBI Special Agent Christopher Holland (Ret.) on crime scene analysis.