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Applied Research, Development, and Method Validation for a Statistically Based Comparison of Tool Marks Using GelSight-Based Three Dimensional Imaging and Novel Comparison Algorithms for Firearm Forensics

NCJ Number
Date Published
March 2016
30 pages
The reported project is a critical next step in investigating the overall performance characteristics of a novel, accurate, and low-cost system (TopMatch) for structural 3D imaging and comparison of cartridge casings.

TopMatch technology shows excellent and continually improving match accuracy; however, in order to fully establish the base credibility of the platform, it was necessary to establish best-scamming practices and to demonstrate that the method meets the quality-control criteria of other forensic instruments. The current project aimed to enhance TopMatch by establishing best practices and conducting a set of methodology studies. The project followed the intent of the Scientific Working Group on DNA Analysis Methods' Validation Guidelines for Analysis Methods document. That document describes seven validation criteria for new scientific methods: Accuracy, Stability, Precision, Repeatability, Reproducibility, Contamination Risk, and Performance Checks. The current project complements the previous studies on "Accuracy" and evidence "Stability" by addressing the remaining issues of Precision, Repeatability, Reproducibility, Contamination Risk, and Performance Checks. In addition, researchers will study the effects of Cleaning Protocols, Focus Variation, and Ambient Lighting Variation. 8 tables, 6 figures, and 3 references

Date Published: March 1, 2016