Law Enforcement Expert's Testimony on Custodial Practices Limited

This action arises out of the death of Jose Sosa ("Sosa") on March 23, 2023 while in custody in the Redondo Beach Police Department Jail.

The Estate of Jose Sosa by and through his successor in interest, N.R. ("Plaintiff"), N.R., individually by and through his guardian ad litem Michelle Rodriguez, and Francisca Rodriguez initiated this action on March 21, 2025.

Defendants sought wholesale or partial exclusion of the Plaintiff's expert, Roger A. Clark's opinions concerning custodial practices, the adequacy of training, medical causation, and constitutional violations.

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

Plaintiff responded that Clark's experience and reliance on training materials and regulations qualify him to address custodial practices. Prior admission of Clark's testimony in other litigation does not establish admissibility of every opinion here, but neither does prior exclusion elsewhere establish that his present custodial-practices opinions must be excluded. The Court granted the motion to exclude only to the extent Clark purports to supply ultimate legal conclusions that Defendants violated Sosa's constitutional rights.

Such legal conclusions are not competent expert testimony. This ruling does not exclude testimony merely because it addresses whether staff conduct conformed to accepted custodial practices, whether training addressed recognized risks, or what trained custodial personnel should observe and communicate.

For purposes of summary judgment, the Court has assumed the admissibility of Clark's opinions within that custodial-practices subject matter and has considered them in Plaintiff's favor. The Court has also assumed the underlying constitutional deprivation, including injury from delayed medical care. Accordingly, its disposition does not depend on excluding Clark's opinions that the care was deficient, that the checks were inadequate, or that earlier intervention would have prevented Sosa's death. The Court does not resolve a disputed factual premise against Plaintiff merely because Defendants' witnesses disagree with Clark.

Whether particular statements venture into medical diagnosis or physiological causation beyond Clark's demonstrated qualifications would require an opinion-specific examination under Rule 702. Because those questions are unnecessary to the present disposition, the Court did not issue a broader admissibility ruling. The remaining requests for exclusion, including the challenges to medical-causation opinions and the reliability of particular custodial-practices opinions, are denied as moot.

Held

The Court granted Defendants' motion to exclude the testimony of Roger Clark solely as to ultimate legal conclusions and otherwise denied it as moot.

Key Takeaway

Police-practices testimony is not inadmissible merely because it addresses institutional standards relevant to whether conduct was reasonable. The Court must distinguish opinions about professional practices and training from opinions declaring that a Defendant violated the Constitution.

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