- 01: Introduction
- 02: History
- 03: Propellants, Firearms, and Ammunition Development
- 04: Modern Firearms Manufacture
- 05: Small Arms Ammunition
- 06: Evidence Handling Procedures
- 07: Equipment and Instrumentation
- 08: Examination of Firearms
- 09: Cartridge and Shotshell Examination
- 10: Characterization and Evaluation of Fired Projectiles
- 11: Bullet Comparison and Identification
- 12: Gunshot Residue and Distance Determination
- 13: Toolmark Identification
- 14: Communicating Results
- Resources
Identification
Home > Bullet Comparison and Identification > Identification
Land impression on a fired lead bullet
Firearms identification is simply a firearms-related specialized subset of toolmark identification. A tool is defined as the harder of two objects; when the harder object is brought into contact with the softer object, the softer object will be marked.
This is what happens when a fired bullet (typically made of some softer metal such as a lead or a copper-jacketed bullet) engages the rifling in the interior of a barrel. Rifling is found in a machined steel surface bearing unique microscopic characteristics as a result of the process of manufacture. When the bullets are fired, the marks are transferred to the surfaces of the fired bullets and appear as parallel striated marks.
Groove impression on a fired lead bullet
AFTE defines striations as contour variations (generally microscopic) on the surface of an object caused by a combination of force and motion, where the motion is approximately parallel to the plane being marked. The toolmarks on fired bullets reflect both class and individual characteristics in their general rifling characteristics and identifiable striae. Subclass characteristics may also be present on the fired bullet surface.
