- 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
U.S. Department of Justice, Office of Justice ProgramsNational Institute of JusticeThe Research, Development, and Evaluation Agency of the U.S. Department of Justice
Inconclusive Results
Home > Toolmark Identification > Toolmark Examination > Inconclusive Results
If the evidence and test toolmarks cannot be matched with each other based on individual marks (no sufficient agreement), possible reasons for the inconclusive result include the following:
- The toolmarks were made by two different tools.
- Damage occurred that caused distortion, deformation, or elimination of microscopic detail in the toolmark.
- The tool was damaged, extensively used, abused, or remachined (i.e., sharpened) between the time the two marks were made.
- Numerous subclass characteristics may be present.
Potential remedies that could be used in certain circumstances to produce better microscopic detail in test marks include these:
- Remount both test and evidence marks end to end on their respective mounts and reexamine them.
- “Smoke” the evidence toolmarks with magnesium smoke to enhance detail. This technique is beyond the scope of this training and should be performed only by an experienced examiner.
- Prepare additional test marks in a different material, possibly a softer material or material more like the evidence item.
- Change the amount, direction, and angle of force employed to create the test marks.
| Note: |
| A study of crime scene documentation and investigative reports often provides insight into the precise orientation of a tool to a toolmarked area at the time the mark was made. This can save considerable time by reducing the number of possibilities. |
