- 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
Elimination
Home > Cartridge and Shotshell Examination > Identification of Impressed Toolmarks > AFTE Range of Conclusions > Elimination
Elimination on individual characteristics
As defined in the AFTE Glossary, elimination is a significant disagreement of discernable class characteristics and/or individual characteristics. For purposes of fired cartridge case and shotshell case comparisons, an elimination is most often based on observed differences in any class characteristic.
However, an elimination based on individual characteristics is more complex. Conceptually, an elimination based on individual characteristics means that if a firearm can be shown to have never been subjected to significant use or abuse over a period of time, the qualitative aspects of the striations produced on fired cartridge cases and shotshell cases should remain the same. A difference in these qualities indicates an elimination.
Elimination based on individual characteristics requires a detailed knowledge of the history and treatment of the firearm, as well as documentation to support the history. It is the responsibility of the examiner to provide this historical documentation. This type of elimination should be approached with caution. Many experienced examiners have never made such an elimination, and the protocols of many laboratories do not allow it.
Eliminations are as sensitive and important as identifications. When eliminations based on microscopic marks alone are permitted by laboratory protocols, the process should adhere strictly to the criteria for an elimination set out in those protocols. When a firearm is included in the evidence and an elimination is based solely on individual characteristics, examiners may add phraseology to their report indicating that their conclusion was based on the condition of the firearm as received or the firearm in its current state of assembly.
