Method and system for determining a similarity or distance measure between ballistic specimens

A system for determining a similarity or distance measure between a first ballistic specimen and a second ballistic specimen, the system comprising:

• at least one processor;
• and
• a non-transitory computer-readable medium having stored thereon program instructions executable by the at least one processor for:
• acquiring topographic data from the first ballistic specimen and the second ballistic specimen of at least one region of interest;
• computing from the topographic data at least one similarity score s for the first ballistic specimen and the second ballistic specimen;
• determining a non-match probability measure of the similarity score for at least one parameter characterizing a macroscopic and/or microscopic feature of the topographic data, the non-match probability measure associating the first ballistic specimen and the second ballistic specimen to a different source;
• and
• correcting the similarity score by determining a corrected similarity score that yields a same value of the non-match probability measure as the similarity score for a reference value of the at least one parameter.