On May 21, 2022, Defendants Deputies Montana Arceo and Brandon Avalos contacted Mr. Lyric Leeyn Cline at an ARCO gas station in Tacoma, Washington, after observing a vehicle they believed matched one involved in recent criminal incidents.
Cline fled on foot, the deputies pursued him, and a struggle followed during which the deputies used physical force, including strikes, before other officers arrived and Cline was handcuffed and transported for medical evaluation.
Cline brought claims for excessive force against Deputies Arceo and Avalos and for failure to intercede against Deputy Avalos.
Defendants retained Mr. Chris M. Nielsen, a retired SWAT officer and police trainer, to offer opinions on police practices and use-of-force. In general, Nielsen opined that the decision to contact and pursue Cline, the types and levels of force used, and the provision of medical care were consistent with generally accepted police training and Pierce County Sheriff’s Department policies.
Law Enforcement Expert Witness
Chris M. Nielsen has approximately thirty-one thousand hours of training and operational experience in patrol-level operations, tactics, supervisory, instructional, and leadership experience. He retired from active law enforcement in December, 2024.
He has an Associate of Arts degree from Bellevue College, a Bachelor of Arts in psychology from the University of Washington (cum laude, Phi Beta Kappa), a Master of Arts degree in political science from the Maxwell School of Citizenship and Public Affairs at Syracuse University and a Juris Doctor degree from the Syracuse University College of Law (cum laude).
Discussion by the Court
A. Reliability and Methodology
Plaintiff challenged Nielsen’s methodology on the grounds that he relied on a limited factual record, did not review Avalos’s deposition before issuing his report or testifying, did not interview percipient witnesses, and did not supplement his opinions after additional discovery. Plaintiff cited portions of Avalos’s testimony and argued that those statements, together with the absence of certain videos from Nielsen’s review, undermine his conclusions.
However, Nielsen reviewed department policies, training materials, reports, medical records, and video, and applied his law enforcement experience to assess the deputies’ conduct under generally accepted police standards and Pierce County policies. That is an accepted, experience-based methodology for police practices experts under Rule 702.
B. Use of Video Evidence
Plaintiff argued that Nielsen’s testimony will not assist the jury because body-worn camera videos depict the encounter and that his descriptions of the footage risk confusing or misleading the jury.
Defendants did not offer Nielsen as a video analyst. They offered him to explain police training, use-of-force frameworks, pursuit and Taser policies, and how officers are trained to assess flight, resistance, and threat. These subjects concern professional standards and decision-making processes outside typical juror experience and fall within Rule 702(a).
The Court, however, enforced certain limits at trial. Nielsen may not narrate the videos or opine on purely factual questions such as where Cline’s hands were at a given moment or whether he in fact assumed a fighting stance. Jurors can reach those factual conclusions. He may testify about generally accepted police practices, relevant policies and training, how officers are taught to assess risk and select force options, and whether the deputies’ decisions were consistent with those standards, assuming specified facts.
C. Legal Conclusions
Plaintiff contended that Nielsen’s opinions that the deputies’ conduct was “necessary,” “appropriate,” and “consistent with training and policy” effectively stated that the force was objectively reasonable under the Fourth Amendment.
Consistent with these principles, Nielsen may not testify that the deputies’ conduct was or was not objectively reasonable, constitutional, or similarly lawful. He may describe policies, training, and generally accepted police practices and state, in professional terms, whether particular actions were consistent with or departed from those standards, based on stated assumptions.
D. Bias and Litigation History
Plaintiff noted that Nielsen has testified exclusively for Law Enforcement Defendants in use-of-force cases and cites his compensation as evidence of bias and unreliability.
However, the Court held that such matters may be explored on cross-examination and left to the jury in assessing what weight to give his testimony.
Held
The Court denied Plaintiff’s motion to exclude the testimony of Chris M. Nielsen.
Key Takeaway
Bias affects credibility and weight, not admissibility under Rule 702. Basically, Nielsen’s litigation history and compensation do not show that his methodology is unreliable or that his opinions lack a factual foundation.
Case Details:
| Case Caption: | Cline V. Arceo |
| Docket Number: | 3:24cv5309 |
| Court Name: | United States District Court, Washington Western |
| Order Date: | February 02, 2026 |
