Gunshot Residue Expert Witnesses: 5

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).

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.

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.

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.

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.