Police - Law Enforcement Expert Witnesses: 20

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.

Cameron Consulting is a physical skills teaching firm that provided contractual instruction to Police Agencies; College Districts; Private Security Companies; Private Corporations and the United States Military for 52 years, having trained approximately 40,000 Enforcement Officers on Arrest Control Tactics and Weaponless Defense.   

Don S. Cameron is a former Staff Member at Santa Rosa Criminal Justice Training Center, Napa Valley College Police Academy, San Joaquin Delta College Police Academy, San Francisco Police Academy and Contra Costa County Sheriff’s Law Enforcement Training Center.  He was a police Officer and Supervisor for 16 years with the Berkeley Police Department and the San Francisco Bay Area Rapid Transit Police Department. 

Worked as a police physical skills and classroom instructor for 52 years. A member of P.O.S.T.’s subject matter expert committee on use of force and less lethal control devises.  Member writer of Learning Domain #20 (use of force), #24 (crowd control), #33 (arrest methods/defensive tactics), #35 (firearms) & #37 (people with disabilities) for the P.O.S.T. Basic Academy.

Litigation Support - Mr. Cameron has served as an Expert Witness on Police Practices cases and Law Enforcement Training for the past 46 years, testifying approximately 500 times. His services include case review, thorough reporting, depositions, and testimony as needed.

Areas of Expertise:

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.

Chief Chet Epperson (Ret.), MBA, has over 44 years of experience as a Law Enforcement / Police Professional for the Rockford Police Department in Rockford, Illinois. Chief Epperson spent 33 years as an active law enforcement officer and 10 of those years as Chief of Police. 

Chief Epperson maintains practical experience as a municipal police chief, implementing several police reforms in his police agency along with accountability processes. He was instrumental in reforming the Rockford Police Department by enhancing its relationship with the community and providing internal and external transparency. Chief Epperson assisted in the formulation of a multi-jurisdictional task force to investigate officer-involved police shootings, in-custody police deaths, and serious uses of force.

Litigation Support - Since 2016, Chief Epperson has been serving as a Police Practices consultant, providing court-appointed expertise in police agency Federal District Court Consent Decrees. He is an expert in applying constitutional standards, state Law, policy, and practice to police incidents. Having Instructed courses on police use of force, internal affairs, and discipline, Chief Epperson is qualified to opine on cases of this nature for both plaintiffs and defendants. His police and jail litigation services include thorough reporting, deposition, and trial testimony as needed.

Areas of Expertise:

View AGR Police Practice Group's Consulting Profile.

Aaron T. Olson specializes as an expert in police investigations and employer investigations. His knowledge and skills come from a career in law enforcement, testifying in state and federal court, being an expert witness, private investigator, adjunct professor, author and trainer. 

Background Experience: Mr. Olson has 26 years of police experience with the Oregon State Police managing assignments in communications, recruitment, and patrol. He supervised and evaluated both police and non-police employees. He was a member of the OSP Procedures and Rules Advisory Committee and worked with Oregon's Department of Justice legal team in rewriting and validating OSP's trooper and cadet applicant hiring process. 

As a patrol supervisor, Mr. Olson directed major crime scenes and motor vehicle fatalities investigations. He reviewed and approved administrative, police, and use of force reports. He investigated allegations of police officer misconduct, conducted background checks, and participated in specialized tasks in community policing, dignitary protection with the U.S. Secret Service and other law enforcement agencies. In his tenure he had experience in police pursuits, the use of physical force and deadly force and next-of-kin death notifications.  

Mr. Olson is a former human resources investigator with Local Government Personnel Institute, Salem, OR. He conducted background and misconduct investigations on city and county employees and city and county elected officials, as well as city police chiefs. His misconduct investigations included sexual harassment, discrimination, retaliation and hostile work environments. He wrote the investigative reports and made the findings of facts on all misconduct allegations.

Besides being an expert witness, Mr. Olson is a private investigator. He is insured and bonded and licensed through the Oregon Department of Public Safety Standards and Training, Private Investigator License #113509. Mr. Olson is a contract expert consultant to the Oregon Public Defense Commission on police practices and investigations. His vendor number is 1833121097-000. 

Mr. Olson is a published co -writer of multiple books, CARE Approach: Seeking Solutions to Human Problems and Multicultural Law Enforcement: Strategies for Peacekeeping in a Diverse Society. Further, he is an adjunct professor teaching at a community college and state university.

Litigation Support: Mr. Olson meets the criteria of an expert witness as outlined in the Federal Rules of Evidence. He has experience as an expert on cases involving police misconduct, police procedures, police and non-police use of force, police pursuits; wrongful death; personal injury; employer investigations on employees; and cases involving employer negligent hiring, negligent training, negligent supervision, negligent retention, management performance and retaliation. He also has experience in reviewing criminal cases for defense attorneys. Mr. Olson's services are available to attorneys' representing plaintiffs and defendants and include diagnostics, thorough reporting, depositions, arbitration hearings, and trial testimony as needed. Contact him today for a free initial consultation.

Areas of Expertise:

View Aaron T. Olson's Consulting Profile.