Arms - Guns - Weapons Expert Witnesses

Capt. David G. Bacon, is a Maritime Expert with over 30 years of vessel charter experience. He has a United States Coast Guard Captains License (Operator of Uninspected Passenger Vessel). His extensive consulting and expert work encompass; personal injuries, propeller strikes, collisions, allisions, running aground, Rules of the Road and navigation. Capt. Bacon's vessel charters include fishing, research, cruising, eco-tours, whale watching, diving, kayaking, photography, oil seeps, and oil spills. As owner/operator, and captain of WaveWalker Charters, he has decades of vessel operations experience with zero accidents and zero injuries. Capt. Bacon is experienced with crew training, safety procedures, crew drills, and practice. The Founder and Executive Director of a nonprofit organization providing at-sea educational adventures for special-needs children and adults, he has extensive knowledge of passenger safety orientation and creating/maintaining a safe environment for passengers, including special-needs passengers in for-profit and nonprofit (501c3) ventures.

Introduction by Captain David G. Bacon

Litigation Support - Capt. Bacon offers expert witness services to attorneys for both Plaintiff and Defendant and has successfully performed in depositions and testimony.  His cases include:

Capt. Bacon has spent 30+ years participating as a technical writer for marine electronics and electrical journals, work procedures, user manuals, magazine articles, on-line publications, and social media. He is a public speaker with 20 years of experience hosting seminars, informational/motivational lectures, and presentations for civic organizations and clubs.

View Capt. Bacon's Consulting Profile.

Brian Zawilinski has over 34 years of Corrections Experience. Currently retired, he served 27 years active duty for the CT DOC, the last 12 served as a Captain / Investigator in Internal Affairs.

Mr. Zawilinski has a significant amount of tactical experience and instructor-training experience in various areas for over 20 years. He has revised policy and curricula, conducted audits, conducted training at various levels, provided leadership training, conducted hundreds of investigations and mentored new supervisors.  

Litigation Support - Mr. Zawilinski is a Subject Matter Expert in use of force, facility operations, facility management, training, investigations and tactical operations. His services include thorough reporting, depositions, and trial testimony as needed. Mr. Zawilinski served as states witness and testified on numerous occasions. 

Ideal Client Engagement: 1) State Attorney General Office 2) Law firms deputized by the AG's Office to litigate cases. 3) Any law enforcement or corrections agency needing assistance 4) Private law firms litigating corrections-based cases.

Areas of Expertise:

Dr. Ron Martinelli, PhD, CMI-V, is a nationally renowned Forensic Criminologist and a federal/state courts qualified law enforcement and premises liability expert who is also a Certified Medical Investigator (physician's level) and a Certified Suicide Investigator. 

Dr. Martinelli directs the nation's only Forensic Death Investigations & Independent Review Team of 26 law enforcement, forensic and medical experts and specializes in officer-involved death cases, civilian self-defense shooting cases and premises liability/security cases. He is a forensic/law enforcement expert to the U.S. Department of Justice, several State Attorney Generals' Offices, numerous major municipalities and nationally prominent private law firms specializing in wrongful death, civil rights and premises liability. 

Dr. Martinelli is the prevailing expert in over 90% of his retained cases. He has saved defendants over $650M and earned plaintiffs over $290 million in jury verdicts and settlements since 2004. He is the media's go-to forensic expert for FOX News, One America News Network, CNN, HLN, Sky News, BBC, NPR, and the History & Discovery Channels. Dr. Martinelli is skilled in officer-involved shootings, in-custody deaths, crime scene reconstruction, forensics, applied sciences, human factors, psycho-medical emergencies and premises liability and security cases. His unique and extensive field experience, combined his academic and scientific credentials, excellent written reports and persuasive testimony, make him a very appealing expert to attorneys and juries alike.

Areas of Expertise:

• Arrests
• Search & Seizure
• Use of Force / Excessive Force - All Levels and Weaponry
• Officer Involved Shootings(OIS)
• In-Custody Deaths
• Criminal Investigations
• Law Enforcement & Corrections Practices, Training & Supervision
• Adult & Juvenile Corrections
• Law Enforcement Negligence
• Civilian Self-Defense, Premises Liability, Security, Foreseeable Harm
• Insurance Cases
• Human Factors

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.

Daniel G. O'Kelly has over 46 years of experience as a range instructor, firearm designer, builder, auditor of licensees, collector, and expert on firearms and ammunition. 

Mr. O'Kelly served for 11 years as a Police Officer and for 23 years as a Special Agent for the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). As one of ATF’s leading firearm experts, he was Lead Instructor of Firearm Technology at the ATF National Academy. Since his retirement from the ATF, he has served as a Senior Corporate Manager for Cabela’s, the then largest firearm retailer in the world, where he co-developed a firearm technology and ATF compliance training program for that company, and is the Founder/Director of IFSA. 

Mr. O'Kelly then founded and is the Director of, the International Firearm Specialist Academy (IFSA), a guild of award-winning experts, former Federal Agents, Investigators, Police Officers, Medical Doctors, and an Attorney, in the Firearm and Forensics field.

Litigations Support -  Mr. O'Kelly has testified continually in depositions and in criminal & civil cases in State, Superior, Circuit, District and Federal Courts since 1978, and has been recognized as an expert witness in Federal and State courts since 1990. He has opined on the topics of:

 Noteworthy Cases

• Retained as Defense expert in the Alec Baldwin case.
• Testified in four Federal trials on the topic of federal firearm definitions from 2014 to 2019 which resulted in ATF undertaking a 2-5 year rewrite of the definition of a firearm “frame or receiver”, which reached a SCOTUS decision in 2022. 
• Testified in trials wherein 1289 items of firearm-related evidence were ruled out by the Court as a direct result of his testimony.
• Worked undercover in three international illicit arms dealing cases, including the Diveroli case which sparked the movie "War Dogs", and is one of two ATF Agents to ever perform an undercover investigation of illicit international firearm trafficking in Europe.   

View Daniel O'Kelly's Consulting Profile.

Kirk DeLeeuw is a highly regarded and accomplished Forensic Biology and DNA Consultant / Expert Witness both nationally and internationally. He has over 20 years of dedicated experience in Molecular Biology and Forensic Science and is well respected worldwide.

Mr. DeLeeuw's career is defined by a deep technical mastery of DNA analysis, including specialized expertise in interpreting complex multi-contributor samples using Probabilistic Genotyping Software (PGS) such as STRmix. Mr. DeLeeuw is licensed by the Texas Forensic Science Commission. He likewise has a comprehensive understanding of FBI Quality Assurance Standards (QAS) and ISO/IEC 17025 accreditation requirements. He applies the standards through meticulous auditing of case files, bench notes, and high-volume electronic data files and images.

Litigation Support - Beyond the laboratory, Mr. DeLeeuw is a seasoned Expert Witness, qualified to provide testimony in Body Fluid Identification / Serology and DNA Analysis across numerous jurisdictions. He has provided sworn affidavits and oral testimony in federal, circuit, and district courts in many states including Washington DC, and internationally in the Royal Turks and Caicos Islands. His ability to translate sophisticated molecular biology data into clear, accessible testimony ensures that scientific integrity remains paramount during both civil and criminal litigations.

Mr. DeLeeuw maintains technical proficiency through a rigorous commitment to continuing education, frequently attending the International Symposium on Human Identification and National CODIS Conferences. His hands-on experience spans a wide array of instrumentation, including Applied Biosystems Genetic Analyzers and Hamilton robotic workstations, as well as various quantification and amplification kits. This combination of technical expertise, regulatory knowledge, and proven courtroom experience allows him to provide unparalleled oversight and analysis in the field of forensic DNA.

Areas of Expertise:

Background Experience - Mr. DeLeeuw's extensive professional background includes high-level roles across private and public sectors. As a Forensic DNA Analyst at DNA Labs International, he analyzed casework from across the United States and internationally, utilizing advanced PCR/STR-based methods and various chemistries. Prior to that, he served for nearly 20 years as a Forensic Scientist for the Michigan State Police.

Ryan Larrison is a senior forensic science and public sector executive with over 25 years of experience spanning Forensic Laboratory Operations, Quality Assurance, Firearms Examination, and large-scale Program and Systems Management within the Michigan Department of State Police.

Mr. Larrison currently serves in a senior leadership role within the Information Technology Division, where he directs a multi-million-dollar portfolio of enterprise systems, operations, and project delivery. In this capacity, he oversees complex, multi-agency initiatives, aligning technical execution with operational and investigative outcomes across multiple state departments. His work includes executive sponsorship of statewide technology programs and the coordination of vendors, stakeholders, and cross-functional leadership teams in high-risk, high-visibility implementations.

Litigation Support - Mr. Larrison serves as an expert witness in cases involving laboratory analysis or laboratory quality assurance. He has been deposed and/or testified over 200 times in the past 5 years.

Areas of Laboratory Expertise:

Background Experience - Prior to his current role, Mr. Larrison served as Assistant Division Director and Quality Assurance Manager for the Michigan State Police Forensic Science Division. In that role, he was responsible for the strategic direction, implementation, and oversight of quality systems across seven accredited forensic laboratories. He led all quality assurance activities, including training, corrective action programs, risk assessment frameworks, and accreditation compliance under ISO 17025 standards. His leadership resulted in a substantial reduction in non-conformities and sustained accreditation across all laboratory operations. 

Mr. Larrison has extensive experience as a program executive and project sponsor for complex forensic and evidential systems. He directed the statewide implementation of the Evidential Breath Alcohol Testing Program, including instrument selection, software integration, vendor coordination, and regulatory compliance, supported by a $2.5 million procurement process. He also led the development and implementation of a Forensic Genetic Genealogy program, establishing quality expectations, vendor deliverables, and investigative reporting standards.

Dean S. Molnar, Jr. is a highly trained and exceptionally experienced Firearm and Tool Mark Examiner, Crime Scene and Firearms Trajectory Analyst, and a proven leader in the field of Forensic Science Operations and Quality Assurance. Mr. Molnar has over 25 years of experience as a certified law enforcement officer and State Trooper, and over 17 years of experience serving as a firearm and tool mark examiner, firearms and tool mark unit supervisor, and laboratory director with the Michigan State Police (MSP) Forensic Science Division.

Litigation Support - Mr. Molnar's experience as a forensic firearm and tool mark examiner includes recognized expert testimony in over 140 criminal cases in both state and federal courts involving both firearms and tool mark identification, crime scene investigation, and shooting reconstruction.  He has personally processed over 60 homicide scenes during his career, including scenes involving shooting reconstruction, photography, and documentation.

Areas of Expertise:

• Firearms function, operability, alterations, defects, conversions, modifications, accidental discharge
• Cartridge manufacture and source determination of ammunition components
• Shooting scene (trajectory) reconstruction
• External and/or terminal ballistics calculations and determinations of the projectile’s trajectory, ricochet, penetration, etc
• Distance determinations (muzzle-to-target determinations) from gunshot residue patterns or shot pellet patterns
• Serial number restorations (firearms, motorcycles and other vehicles, bicycles, etc.) – anything with an identifying characters, numbers or markings that have been obliterated either intentionally or by wear or corrosion

Background Experience - Mr. Molnar’s leadership experience has included firearms unit supervisor duties at three different laboratories. He currently serves in a key role as the Laboratory Director at the Michigan State Police-Lansing Laboratory where he is specifically assigned as the operations director for pattern disciplines.

Mr. Molnar also has over seven years of quality assurance experience as an ANSI National Accreditation Board (ANAB) assessor. His years of experience include almost 15 years of ongoing training within an extremely professional and accredited crime scene processing program at MSP, along with even more specialized training in firearms trajectory analysis. Mr. Molnar holds a Bachelor of Science in Fire Science and a Bachelor of Science in Criminal Justice from Lake Superior State University. He is a long-time member of the Association of Firearms and Tool Mark Examiners (AFTE) and is also a member of the American Society of Crime Laboratory Directors (ASCLD).

Lawrence R. Porte is a nationally and internationally recognized Investigative Analysis Expert and Trial Assist Analyst with more than forty (40) years of experience in federal law enforcement, protective intelligence, targeted violence assessment, aviation security, and criminal investigations.

Mr. Porte's distinguished career spans service with the United States Secret Service, the Department of Homeland Security, the Transportation Security Administration, higher education, and municipal law enforcement, giving him rare depth in both operational and analytical aspects of complex investigations.

 Litigation Support - Mr. Porte is widely respected for his ability to assess investigative integrity, identify behavioral warning signs, and provide clear, well-supported analyses. His current consulting work focuses on investigative case review, litigation assist support, and threat assessment for attorneys and institutions confronting high-risk or procedurally complex matters.

Areas of Expertise:

Background Experience - During his federal career, Mr. Porte held senior leadership positions with the United States Secret Service and later served as Special Agent in Charge for the Transportation Security Administration, where he directed investigative operations across a 14-state region that included approximately 110 federally protected airports. In that capacity, he supervised criminal investigations, cargo security matters, and internal misconduct inquiries, while also helping develop the TSA’s first Workplace Violence Policy and the agency’s Integrity Test Program aimed at combating theft and misconduct in airport environments.

Earlier in his career, Mr. Porte served on the White House Presidential Protective Division and was a member of the first White House Counter Assault Team, experiences that placed him at the center of some of the nation’s most sensitive protective and intelligence operations. He also opened and managed the Saginaw Resident Agent Office and later served as Special Agent in Charge of the Detroit Field Office, with oversight of additional Michigan offices.

Mr. Porte’s national and international recognition is further reflected in his participation in significant protective intelligence and investigative matters, including a threatened assassination plot involving Indian Prime Minister Rajiv Gandhi and an operation connected to extremist networks and coordinated activity extending into Canada. 

Dr. James F. Pastor, Ph.D, JD, CPP, is a multifaceted security expert with a rich background that spans security, policing, legal, and academia. His career began as a tactical officer in Gang Crime Enforcement with the Chicago Police Department, where he gained hands-on experience in one of the nation's most dynamic policing environments. This real-world foundation laid the groundwork for his extensive expertise in security, policing, and public safety.
 
 Transitioning from the streets to the courtroom, Dr. Pastor built a distinguished legal career representing police unions, security guard and electronic security firms, corporations, and religious institutions. His comprehensive counsel and advice to litigation attorneys, corporate counsel, and policy makers is grounded on real world experience and practical understanding.
 
With a doctorate in Public Policy Analysis, Dr. Pastor brings vision and understanding of how policies shape incentives and influence human behavior. This academic insight, combined with his extensive experience, gives him a unique perspective on risk and liability, making him a sought-after advisor for corporations and communities aiming to prevent crime or mitigate its impact.
 
Dr. Pastor’s security sense is a blend of street-level policing intuition, academic scholarship, legal expertise, and technical know-how, further enhanced by a deep understanding of geopolitical trends. His decades-long study of terrorism and extremism also informs his work, allowing him to contribute valuable insights and assessments in a variety of settings.

Areas of Expertise:

Litigation Support - Dr. Pastor is a highly regarded expert witness with experience in policing, security, public safety, and legal issues relating to these. His depth and breathe of experience is substantive, yet practical. Bringing a unique background, along with credentials and skills, including participating in over 750 prior depositions, has proven to be very effective in his expert witness role.

Dr. Pastor has over 20 years of university teaching experience in security, public safety, and policing, including Northwestern University- Center for Public Safety and the International Law Enforcement Academy. 

Author of four books on security and public safety, plus chapter on Private Policing in ASIS International's Protection of Assets Manual and created Privatization of Policing Bibliography for Oxford University Press, both being comprehensive, substantive works relating to Private Policing.

View SecureLaw LLC's Consulting Profile.

Dr. Roy G. Taylor is a current Chief of Police with over 40 years of experience in a wide-range of federal, state, local, and private criminal justice positions. Dr. Taylor specializes as an expert witness in Police Practices and Procedures and Law Enforcement and Criminal Justice. Current Positions:

• Chief of Police Blue Ridge Public Safety (2014)
• President/CEO Signal 88 Security of Charlotte (2012)
• President/CEO Capitol Special Patrol (2012)
• Chief of Police Capitol Special Police (2002)
• Lt. Colonel – Provost Marshal, Army National Guard (2000)
• Antiterrorism / Emergency Management Branch Chief DoD (2007)
• Provost Marshal Joint Civil Support Task Force, Joint Chiefs of Staff (2014)

Litigation Support - Dr. Taylor is called upon to analyze cases from both defense and plaintiff perspectives. His services include case review, written reports, deposition, and trial testimony as needed. 

Areas of Expertise:

View Roy Taylor's Consulting Profile.

Emanuel Kapelsohn is an internationally recognized Firearms Training and Use of Force consultant who has instructed thousands of police and security officers, federal agents and others throughout the U.S. and abroad since 1980. A graduate of Yale University and Harvard Law School, he is a practicing attorney in addition to his consulting work. 

As vice president of the Internat’l Assoc. of Law Enforcement Firearms Instructors, Mr. Kapelsohn is a certified in force science and shooting scene reconstruction, and as an instructor in numerous law enforcement disciplines. He is a featured presenter at national and international instructor conferences. He has authored over 130 published articles, is Associate Editor of "Standards & Practices Guide for Law Enforcement Firearms Instructors," and principal author of "Firearms Training Standards for Law Enforcement Personnel," and "Guidelines for Simulation Training Safety." 

Mr. Kapelsohn testifies as an expert witness in civil and criminal cases in state and federal courts nationwide, and has testified by invitation before both houses of Congress. 

Testimony on the Following Subjects:

View Emanuel Kapelsohn's Consulting Profile.

Adam Bercovici has over 40 years of experience in the Police and Security field. Mr. Bercovici spent 30 of those years with the LAPD, 20 as a supervisor and manager. He is currently a retired LAPD lieutenant and former security company CEO.

Background: Mr. Bercovici's leadership assignments included the Criminal Investigation Section- Major Crimes Division-The Joint Terrorism Task Force, The FBI Violent Crime Task Force ( where he supervised the FBI Fugitive Task Force), The Special Investigation Section, and Homicide Special Section. 

Since 2012, Mr. Bercovici has worked as a subject matter expert and consultant in Police Practices and Complex Police Investigations. His clients have included major law firms, insurance companies, and corporations.  Mr. Bercovici is currently retained on several high-profile cases.  He is an experienced Expert Witness who has written numerous Rule 26 Reports and has testified in both State and Federal courts.  Writing examples can be provided.  Mr. Bercovici has been an on-air talent, producer, and script and story consultant in the entertainment industry.  He was the Co-Talent on The History Channel Series JFK Declassified-Tracking Oswald.  Mr. Bercovici was the Executive Producer for American Cartel for Discovery Plus. 

Litigation Support: Adam Bercovici splits his work between defense and plaintiff. He has been retained by prominent civil rights firms, major municipalities and their legal counsel, plaintiff attorneys, city attorneys, and criminal defense attorneys. Mr. Bercovici accepts work based on the merits of the individual case.

Areas of Expertise: 

Internationally recognized expert on Firearms History and Values. Consulting, appraisals, expert witness services, and museum exhibit design. Retired director of NRA Museums Division, overseeing 3 national firearms museums & curating NRA's 10,000 gun collection.

Writing & Media - Editor of leading price guide Standard Catalog of Firearms. Author of hundreds of articles and nine firearms books.  200+ national TV appearances as Gun Expert.

Attorney (inactive)  J.D.  AGI certified firearms appraiser.