The firearm / 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 pesence 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 assualts for comparison with weapons submitted by police agencies.