Fingerprinting — Bullet

When a gun is fired, several mechanical actions leave distinct impressions on the ammunition. These marks are primarily categorized into two types: 1. Striation Marks (on the bullet)

Bullet fingerprinting, more formally known as , is a forensic technique used to match a fired bullet or shell casing to a specific firearm. The "fingerprint" consists of unique, microscopic marks left on the ammunition by the gun's internal components during the firing process. While often portrayed as a flawless investigative tool in television dramas, the reality of its scientific reliability is a subject of significant debate within the forensic community. How It Works: The Mechanical Fingerprint bullet fingerprinting

: Microscopic flaws in the manufacturing process or wear and tear from use create a "signature" unique to that specific barrel. 2. Impression Marks (on the casing) When a gun is fired, several mechanical actions

: The pin strikes the primer at the back of the casing, leaving a unique indentation. The "fingerprint" consists of unique, microscopic marks left

Despite its usefulness, "bullet fingerprinting" is not always a definitive proof of guilt. Several factors can complicate or even invalidate a match. 1. Barrel Evolution

The shell casing is also marked by various parts of the firearm's internal mechanism:

Barrel uniqueness in firearms: reliable forensic match? - Facebook