Ballistics Matching Using 3D Images of Bullets and Cartridge Cases: Final Report

• NCJ Number: 182567
• Author(s): Benjamin Bachrach
• Date Published: 1999
• Length: 55 pages
• Grant Number(s): 97-LB-VX-0008
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

This report presents the methodology and findings of a study designed to determine whether three-dimensional (3D) information from a bullet's surface can be successfully exploited to improve the matching rate of existing automated search and retrieval systems.

Abstract

This required the development and implementation of all the elements of an acquisition component. Moreover, this particular acquisition component operated based on 3D captured data, as opposed to 2D captured data. Together with the acquisition component, a preliminary version of a correlation component was developed to verify the usefulness of the 3D captured data. The complete automated search and retrieval system was tested by two types of independent evaluations. The first evaluation involved bullets being fired by three different guns whose barrels were manufactured consecutively. The challenge to the system was to group the different bullets correctly. This set of bullets was used to "tune" the many parameters in the numerical algorithms of the system. The second type of evaluation was meant to emulate a more "real life" situation. These evaluations involved so-called "blind tests." Researchers were provided with both control bullets from different guns and with questioned bullets. The task was to identify which gun fired each of the questioned bullets based on the data obtained from the control bullets. Two sets of tests were performed, the first with six guns and the second with five guns. In both cases the system was able to correctly identify which gun fired each of the questioned bullets. 22 exhibits