Police Practices and Procedures Expert Witnesses: 21

Global Forensic Services, LLC (GFS) is a Forensic Consulting, Laboratory and Investigative Firm offering over 44 years of experience and training in a wide range of forensic science and private investigation disciplines.

Larry Stewart has personally examined tens of thousands of individual items of evidence from sources such as state, local, and federal agencies (e.g. Federal Bureau of Investigation, Secret Service, Bureau of Alcohol, Tobacco and Firearms, Central Intelligence Agency, and others), and foreign governments. On several occasions he has examined cases involving international disputes between governments. 

Mr. Stewart has testified as an Expert Witness in state, federal and military courts of law, as well as in foreign court systems to include; Austria, Australia, Canada, Germany, Singapore, Sri Lanka, Switzerland and Thailand. He has also testified at The Hague in the Netherlands and three times as an expert before the U.S. Congress. 

Areas of Expertise Include:

My name is David T. Sweeney.  I am a Police Policy and Procedure expert and a retired 34-year veteran police leader with Seattle Police and Oregon State University PD.  I have decades of experience supervising a large number of police officers and supervisors. I am currently employed as adjunct faculty in the School of Police Staff and Command at Northwestern University. I enjoy assisting with expert reviews of policing best practices for a variety of legal standards for police departments. As an expert witness, I have been pleased to work with both plaintiff and defense attorneys. I will give you an honest assessment of your case, so that I can provide the best reports and helpful testimony. I have experience with 65+ total cases: 1/3 defense cases and 2/3 plaintiff cases.

Litigation Support - My goal is to improve best practices in policing by offering expert witness and police consultation services. I am also a trained mediator specializing in workplace conflicts. I provide honest, unbiased opinions. I will be happy to review and discuss your case. I will point out strengths and weaknesses of the case, and we can work on next steps, whether it be further case review, expert report, deposition, or trial testimony. I have spent 21 years as a sergeant and lieutenant, responsible for training and reviewing topics such as police pursuits, use of force, police tactics, de-escalation, police supervision, less lethal weapons, active shooter, SWAT, crowd control, legal standards, EEO, Human Resources, U.S. 1983 cases, and more.

 Areas of Expertise:

View David T. Sweeney's Consulting Profile.

Donald L. Leach, II, is a Jail / Corrections Management expert with over 30 years of experience. He has 20 years of consulting experience on jail management issues nationally, focusing on Risk Management for Jails and Jail Operational Methodology. 

Mr. Leach has extensive supervisory experience, having overseen up to 402 employees (indirectly). He also supervised internal affairs investigations, experienced in interviewing, hiring, training, scheduling, motivating, evaluating, and dismissing personnel. He is experienced in administering and managing a large detention facility, developing and administering programs, budgeting, contract development and monitoring, conducting research, monitoring compliance with policies and procedures, community relations, public speaking, controlling costs, problem-solving, and preparing reports.

Litigation Support - Mr. Leach has served as an expert witness for 5 years, in both State and Federal court. His services are available to counsel for both Plaintiff and Defense and include case review, testimony, and consultation for jail and prison issues.

Areas of Expertise:

View Donald Leach's Consulting Profile.

Dr. John R. Black is a recognized expert with extensive experience in international, federal, and state courts on Lethal Force, Police Use of Force, Officer-Involved Shootings, and Civilian Self-Defense, blending forensic analysis with human-centered perspectives and systems thinking. Dr. Black employs a systems thinking approach that enables him to view incidents from multiple perspectives. He regularly speaks to Police leadership, investigators, lawyers, and organizations about how we think about the process of inquiry, our biases, and our sensemaking.

Litigation Support - Dr. Black is qualified as an expert witness in state and federal courts related to police practices, police use of force, decision-making, officer-involved shootings, police tactics, police training, incident command, and police / jail operations. He is also qualified with similar expertise for civilian self-defense and use of force events.

Expert in Use of Force & Lethal Force Incidents & Decision-Making

In cases involving force--lethal force, understanding decision-making is as critical as the facts themselves. Whether you are a defense attorney explaining your client’s actions or a prosecutor challenging them, you need an expert who integrates both events and decision-making processes. Dr. Black offers a unique approach, blending quantitative precision with qualitative insight into how individuals make sense of their world. he is a recognized expert with experience in international, federal, and state courts on lethal force, police use of force, officer-involved shootings, and civilian self-defense. He combines forensic analysis with human-centered perspectives, ensuring a balanced view that benefits both defense and prosecution.

Advanced Forensic Video and Qualitative Analysis

Video evidence often plays a pivotal role in determining the facts. Dr. Black is skilled in forensic video analysis, using Amped Five software to extract key details. What sets him apart is his ability to combine video analysis with qualitative thematic tools like Atlas.TI, understanding both what happened and how individuals interpreted their environment under stress.

Cognitive Interviewing and Human Performance Expertise

Dr. Black specializes in cognitive interviewing, exploring clients’ mindsets during critical moments leading up to the use of force. His approach bridges the quantitative analysis of human performance with qualitative insights into violent encounters, offering a comprehensive view of why actions were taken.

Military and Law Enforcement Expertise

With 30+ years in U.S. Army Special Forces and 23+ years in law enforcement, Dr. Black brings unmatched experience to each case. He provides practical insights grounded in real-world experience. His background ensures a comprehensive understanding of how policy, training, and decision-making intersect under pressure.

View Aragon National, Inc.'s Consulting Profile.

Andreu Experts is a premier expert witness and consulting firm specializing in Law Enforcement Practices, with a distinct focus on Homicide Investigations, Use of Force, and Complex Criminal Case Analysis. Founded by a former Chief of Police with more than 45 years of distinguished law enforcement experience—including over two decades dedicated to homicide investigations—Andreu Experts delivers authoritative, fact-driven opinions grounded in real-world investigative leadership.

Their firm provides comprehensive expert services to both plaintiff and defense attorneys in state and federal courts. They are retained in cases involving wrongful death, police procedures, investigative failures, officer-involved shootings, and allegations of misconduct. Every opinion rendered is the product of meticulous case review, careful analysis of reports, witness statements, forensic evidence, and adherence to generally accepted law enforcement standards and practices.

What distinguishes Andreu Experts is not only the depth of experience, but the credibility and clarity brought to each case. Having led major investigations and supervised detectives in high-stakes environments, their principal understands how investigations should be conducted—and where they fall short. This perspective allows them to identify critical issues, explain complex procedures in plain terms, and assist attorneys in building compelling, well-supported arguments.

Services include case evaluation, report writing, deposition and trial testimony, and trial preparation support. They work closely with legal teams to strengthen case strategy, anticipate opposing arguments, and present findings in a manner that resonates with judges and juries alike. Whether retained early in litigation or brought in to assess an existing case, Andreu Experts provides objective, defensible opinions that stand up under scrutiny.

Andreu Experts' commitment is to professionalism, integrity, and precision. They do not advocate—they analyze. Their role is to assist the trier of fact in understanding what occurred, why it matters, and how it aligns with accepted law enforcement standards. When experience matters and credibility is critical, Andreu Experts is a trusted partner in the pursuit of justice.

Michael McNeill - Retired Sheriff’s Commander has over 32 years of progressively responsible Law Enforcement experience.

Client Engagement: Attorneys and law firms handling matters involving law enforcement practices, police operations, use of force, officer-involved shootings, vehicle pursuits, criminal investigations, supervision, policy compliance, detention or custody operations, and related civil-rights or public-entity litigation. Available to assist both plaintiff and defense counsel.