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Mapping Microscopic Surfaces Could Help Solve Crimes


3D firing pin impression
Example of a 3D image of firing pin impression showing microscopic surface features. Credit: NIST.

Topographic maps that display surface features like mountains, valleys and coast lines, have long helped people navigate great distances. Forensic science researchers are now looking to topographic maps of microscopic features, like ridges, bumps and roughness, to aid in solving crimes.

Forensic experts who specialize in ballistics matching could be among the first to use detailed surface maps of microscopic features on fired bullets and casings, but the technology also has future promise for other types of pattern evidence including toolmark and shoe impressions analysis.

However, a number of technical challenges must be met before micro-scale topographic surface maps can be used to analyze evidence. To address these challenges, the National Institute of Standards and Technology (NIST) and the National Institute of Justice (NIJ) are holding the first meeting of the Forensic Optical Topography Working Group in Gaithersburg, Md., March 17-18, 2015.

The Forensic Optical Topography Working Group, which includes NIST scientists and engineers, is sponsored by the National Institute of Justice Forensic Science Center of Excellence.

This meeting will mark the start of the working group's efforts on the technical challenges, many of which are related to standards and inter-comparability across laboratories, such as:

  • standardization of data transfer
  • best practices for evidence comparisons
  • standard calibration methods, and
  • inter-laboratory studies.
Released March 10, 2015, Updated January 20, 2023