Goal: To build a scientific infrastructure for objective forensic firearm and toolmark analysis with a rigorous evaluation of uncertainty to quantify the strength of the evidence for expert testimony in court proceedings.
When a firearm is fired it leaves marks on the bullet and cartridge case. Forensic firearm and toolmark examiners compare these marks to evaluate whether a bullet or cartridge case recovered at a crime scene was fired by a particular firearm. A similar comparison is performed for marks left by other tools, such as screwdrivers, pry bars, and bolt cutters.
The comparison of toolmarks is currently a subjective process that relies on the skill and expertise of the examiner. NIST is working with the forensic community to augment an examiner’s testimony with objective measures for toolmark similarity and the strength of the evidence.
Firearm and toolmark analysis are transitioning from the use of comparison microscopes to the acquisition and comparison of three dimensional (3D) toolmark topography images. This new technology requires standards and procedures to ensure measurement data interoperability and traceability.
Developing standards, reference artifacts, and procedures for measurement quality assurance and interoperability
Building research and reference databases of toolmarks for method development and statistical evaluation of the strength of the evidence
Developing objective metrics and algorithms for evaluating the similarity of toolmarks
Developing statistical models and procedures to quantify the strength of the evidence.
Registry notches its 100th standard, marking a milestone for the forensic science organization.