The Firearm and Tool Mark Section performs analyses in several areas of comparison. The examiners can identify the firearms used during a crime by microscopically comparing crime scene bullets with known test fired bullets. Serial numbers which have been damaged can be restored using chemicals. Thus stolen firearms can be traced to their owners. Investigations can be aided by analyzing for the presence of gunshot powder particles. When a tool is used to pry something open, the examiner can compare the characteristic marks left at the crime scene with those of the suspected tool. This section also maintains an open case file which contains bullets and cartridge casings from unsolved homicides and serious felonious assaults for comparison with weapons submitted by police agencies.

The section examines approximately 1500 cases per year, including such procedures as bullet and cartridge case comparisons, serial number restorations, weapon operability, tool mark analysis, and firing distance determinations.