AFTE Range of Conclusions
Definition
Association of Firearm and Tool Mark Examiners standard scale: Identification, Inconclusive (A, B, C), Elimination, Unsuitable for examination. The same scale used in bullet comparison.
- Issuing body
- Association of Firearm and Tool Mark Examiners (AFTE)
- Conclusion tiers
- Identification, Inconclusive A/B/C, Elimination, Unsuitable
- Basis
- Pattern match of class and individual characteristics
- Also applies to
- Cartridge case and bullet comparison
Common questions
Why does the scale split Inconclusive into A, B and C?+
The three sub-tiers record why an examiner could not reach identification or elimination: A means agreement of some individual characteristics but not enough for identification, B means agreement of class characteristics with unresolved individual marks, and C means poor-quality or insufficient marks to compare at all.
Is an AFTE Identification the same as a numerical statistical match?+
No. The conclusion is a subjective examiner judgment based on training and experience, not a calculated probability. This has drawn criticism in admissibility challenges, since the AFTE theory does not specify a fixed threshold of matching marks required for identification.
Related terms
- Class Characteristic
- A feature shared by an entire group of objects (every shoe of one model has the same sole tread; every tire of...
- Combination Mark
- Both impressed and striated features in the same mark, typical of pry-bar and chisel attacks where the tool first bites into the...
- Impressed Mark
- Also called indented or compression mark. Tool is pressed perpendicularly into the softer surface and reproduces the contour of the tool's working...
- Individual Characteristic
- A characteristic unique to a specific typewriter unit arising from manufacturing variation or service wear; used to identify or eliminate a specific...
- Mikrosil
- Brand-name silicone polymer casting compound (also Microsil, AccuTrans) used to lift a fine-detail negative of a tool mark from the scene without...
- Striated Mark
- Also called scratch, abrasion or scrape mark. Tool slides laterally across the surface and leaves parallel striations from microscopic imperfections on the...
- Subclass Characteristic
- Batch-level feature introduced by manufacturing-tool wear that is shared by a sub-population of tools made in the same production run (a die...
- Toolmark
- The microscopic striations and impressions left on a softer material (a bullet, a cartridge case, a lock body) by contact with a...