The Organization of Scientific Area Committees (OSAC) for Forensic Science has placed two new standards covering firearm and toolmark analysis on its Registry of Approved Standards. According to a recent news release, these new standards provide guidance on implementing 3D technologies in forensic labs.
The new standards are:
- ANSI/ASB Standard 062, Standard for Topography Comparison Software for Toolmark Analysis
- ANSI/ASB Standard 063, Implementation of 3D Technologies in Forensic Firearm and Toolmark Comparison Laboratories
The new release noted that researchers have been developing new methods that use 3D surface scanning microscopes to produce 3D models of the bullets, and computer algorithms can then compare the microscopic features of the two virtual bullets to measure how similar they are.
“These standards give labs guidance on purchasing and setting up a 3D system, validating it to ensure that it produces accurate results, and implementing it into their workflow,” said Erica Lawton, a firearms examiner at the Alabama Department of Forensic Sciences who, as the chair of OSAC’s Firearms and Toolmarks Subcommittee, helped guide the new standards through the approval process.
According to the news release, a benefit of using a 3D system for comparing the surface features of two bullets or cartridge cases is that the algorithm generates a numerical score that describes how closely the two surfaces match. “That match statistic expresses the amount of uncertainty in the analysis, and police investigators, jurors and others can use it when weighing the evidence. With the traditional method, an expert can only give a subjective opinion as to whether two bullets or cartridge cases were fired from the same gun. They cannot provide a match statistic,” stated the news release.
The National Institute of Standards and Technology (NIST) administers OSAC as part of its larger Forensic Science Program, which works to strengthen forensic science through advanced research and improved standards. NIST also supports laboratory efforts to implement standards on the OSAC registry via a cooperative agreement with the American Academy of Forensic Sciences. For more information on OSAC’s role in the standards development process, visit the OSAC website.
The Center for Statistics and Applications in Forensic Evidence (CSAFE), a NIST Center of Excellence, is developing statistical and scientific foundations for assessing and matching firearms and toolmarks. Learn more about CSAFE’s work in this area at https://forensicstats.org/firearms-and-toolmark-analysis/.