Identifying persistent and characteristic features in firearm tool marks on cartridge cases.

Area of Science:

• Forensic Science
• Ballistics
• Computer Science

Background:

• Subjectivity concerns in traditional firearm identification methods.
• Need for objective, quantitative comparison of firearm tool marks.
• Development of algorithms for analyzing impressed tool marks on ammunition.

Purpose of the Study:

• To develop an algorithm for identifying consistent and significant firearm tool marks.
• To generate a quantitative similarity metric for tool mark topography.
• To improve discrimination between same-firearm and different-firearm comparisons.

Main Methods:

• Algorithm development for impressed tool mark analysis on cartridge cases.
• Feature extraction emphasizing consistency and persistence across firings.
• Creation of a surface similarity metric based on tool mark topography.

Main Results:

• A characteristic surface map representing persistent tool mark features.
• Improved discrimination between comparison scores of same vs. different firearms.
• Visualization of similarity areas for quantitative support.

Conclusions:

• The algorithm enhances objectivity in forensic firearm identification.
• Quantitative analysis of tool marks improves comparison accuracy.
• The method aids examiners by providing visual and quantitative evidence.