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Applied Research, Development, and Method Validation of Toolmark Imaging, Virtual Casing Comparison, and In-Lab Verification using a GelSight-Based Three Dimensional Imaging and Analysis System for Firearm Forensics

NCJ Number
Date Published
February 2017
43 pages
Stemming from a previous project that developed a 3D surface topography imaging and analysis system for forensics based on the GelSight scanning technology and custom feature-based image comparison, the three objectives of the current project were 1) to develop the ability to scan and compare firing pin impressions (FPIs); 2) to examine the use of the imaging and analysis technology in a live lab experiment; and 3) to investigate Virtual Microscopy (VM), the use of measured 3D surface topographics as a substitute for physical casings.

The project successfully completed these three objectives during the project period of 1 year. A protocol was developed for scanning and analyzing FPIs, and the latest scanning system was deployed to crime labs for the role of such a system in verification. Software was developed for Virtual Microscopy (VM), and the research team recruited 15 labs and 56 individuals to participate in the VM examiner study. The team is developing measurement and analytic techniques that are able to provide accurate quantitative sample comparison and database search. It is also expanding the types of tool marks that can be analyzed by scan acquisition hardware. Overall, this work benefits the criminal justice system and its ability to present firearm identification and tool-mark evidence in the courtroom. Additional impact will be made as more crime labs become aware of the work through dissemination of results. 22 figures, 1 table, and 6 references

Date Published: February 1, 2017