Ballistic signatures


1. Unlike human fingerprints or DNA, ballistic signatures DO change.

Wear through shooting the firearm, or intentional changing or alteration of the barrel and certain parts (bolt/slide face, firing pin, extractor, ejector) will change the ballistic signature.


2. In the case of new guns coming off the production line, ballistic signatures are NOT unique.

These signatures are the result of tool marks left by the rifling cutter and parts such as the bolt face, extractor and ejector. Newly-produced firearms are generally uniform in these features, especially in barrels coming off the production line sequentially.


3. There are currently more than 200 million firearms in circulation in the U.S. No discussion has been made of an attempt to take a ballistic signatures of these guns.

This would be an extremely costly and time consuming measure, and one that would have little or no impact on solving crimes. Most guns used in crimes are stolen.


4. Ballistic signatures are most useful as a tool to tie a recovered firearm (from a crime scene or suspect) with ballistic evidence (bullets, cartridge cases) left at the crime scene.

The greater the time separating the gun from the crime, the less likely ballistic signatures will prove effective. Ballistic characteristics have been available as a crime lab tool for decades and have been instrumental tying recovered guns to crime scenes. It fails the cost-benefit test when applied to any general collection of sample cartridges cases and bullets.


Note: we intentionally do not use the term "ballistic fingerprint" because we believe it to be misleading. Ballistic signature or ballistic characteristics is a more accurate description of the marks left on the bullet and cartridge case by a firearm.