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Expanding the Scope and Efficiency of 3D Surface Topography Analysis in Firearm Forensics

NCJ Number
Ryan Lilien
Date Published
September 2021
43 pages

This is the Final Research Report on the findings and design of a project with the goal of extending the researchers' technology for 3D imaging to the examination of bullets.



One phase of this research focused on developing tools for high-resolution scanning and analysis of bullets. The second phase evaluated the use of a portable 3D scanning system within the crime lab. In the project’s first phase, the research team developed an automated bullet-scanning process and then evaluated that process on a small set of test fires. The bullet scanning process uses a batch scanning tray that fits into the researchers’ current scanner platform. The process was tested with a small set of test fires collected for the study. In the second phase of the project, the team completed a scanning study with its portable scanner. A core set of test-fired cartridge cases was scanned by four individuals using two portable systems and the team’s desktop system. Scans were compared to demonstrate the scan quality and consistency of the portable unit. Both project phases were completed during the specified project period. The first phase demonstrated that the team’s TopMatch scanning platform is capable of measuring, visualizing, and comparing pristine and damaged bullets. The project’s second phase demonstrated that the measurements acquired by each operator on each system are highly consistent, without a significant difference in scans collected by different operators or systems. Collaboration with crime labs is continuing in collecting scan data, eliciting feedback from practitioners, and instructing examiners and trainees.