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Addressing Quality Assurance Issues in 3D Firearm and Toolmark Imaging



Michael T. Stocker, Robert M. Thompson, Johannes A. Soons, Thomas B. Renegar, Xiaoyu A. Zheng


The emerging capability for measuring and analyzing the three-dimensional (3D) surface topography of forensic samples is expected to have a profound impact on firearm and toolmark identification. As forensic laboratories are working to integrate 3D topography metrology into actual casework, it is critical that quality assurance guidance is in place on how to select a suitable measurement instrument and how to ensure that the instrument performs to specification. While progress towards these goals are being made in several standards organizations for generic applications, there remains a need for additional detailed documentation that applies to firearm and toolmark identification. This report describes research efforts to provide practitioners with: 1) well-defined performance specifications to fairly evaluate and compare instruments, 2) procedures on how to validate that an instrument meets specifications upon installation, 3) quality assurance procedures to verify ongoing instrument performance and 4) a custom set of physical reference standards designed specifically for calibration and quality control of surface topography instruments being used for firearm and toolmark identification.
Journal of the Association of Firearms and Toolmarks Examiners
Spring 2018


3D, measurement uncertainty, performance specifications, quality assurance, reference artifacts, surface topography


Stocker, M. , Thompson, R. , Soons, J. , Renegar, T. and Zheng, X. (2018), Addressing Quality Assurance Issues in 3D Firearm and Toolmark Imaging, Journal of the Association of Firearms and Toolmarks Examiners (Accessed June 14, 2024)


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Created April 1, 2018, Updated August 30, 2018