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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.
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.

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