Just 3D Optical Topography

Just 3D Optical Topography


Episode Three of Just Science, funded by the National Institute of Justice’s Forensic Technology Center of Excellence [Award 2016-MU-BX-K110], features Dr. Ryan Lilien, from Cadre Forensics and Todd Weller, from the Oakland Police Department talking about their groundbreaking research in optical topography and firearms identification. Optical topography is a means to give firearms examiners data that is close to a perfect representation of an impression. This research provides the possibility that in the future we will be able to relate the human examiner’s judgment to a statistical representation.

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Ryan Lilien, MD/PhD.  Ryan is the head of research at Cadre Research and has worked in scientific computing for over twenty years. His research expertise focuses on the use of advanced scientific computing and statistical models to solve interdisciplinary research problems. Ryan earned an MD/Ph.D. from Dartmouth Medical School and Dartmouth’s Department of Computer Science. Ryan was faculty at the University of Toronto cross-appointed between Computer Science and the Faculty of Medicine. The Gates Foundation recognized his drug discovery research with a prestigious Grand-Challenges Grant. He has received additional research funding from the NIJ, NIST, and Canada’s National Sciences and Engineering Research Council. Ryan leads development of the TopMatch-GS 3D system (a novel 3d imaging and analysis system for firearm forensics and virtual microscopy). He’s presented his group’s steady progress on developing and validating the system at recent national and regional AFTE meetings. Ryan is also currently a member of NIST’s OSAC Subcommittee on Firearms & Toolmarks.




Todd Weller has been a Criminalist for over 17 years.  He worked for the Oakland Police Department for over 16 years and now is in private practice.  He has performed casework in drug analysis, DNA, crime scenes, and for the past nine years has worked in the firearms identification specialty.  He graduated from the National Firearms Examiner Academy (NFEA) in 2009. Todd has a B.A. in biochemistry/molecular biology from Dartmouth College and a M.S. in forensic science from the University of California, Davis. For his master’s thesis, Todd collaborated with NIST to study confocal microscopy on test fires from consecutively manufactured firearms.





Additional Content

Cadre Research link:
TopMatch GS 3D:
OpenFMC file format X3P:
NIST Ballistics Toolmark Research Database:
Forensic Optical Topography Working Group Meeting, Report: