Forensic Scientists assigned to the Firearms Unit conduct examinations of firearms and toolmark evidence to determine if a specific firearm or tool was used in a crime. This is completed through the comparison of cartridge cases, bullets, and toolmarks on other evidence items to test samples using a comparison microscope. Additional examinations that are completed by the Firearms Unit include firearm function testing, muzzle to target distance determinations, ejection pattern testing, serial number restoration, and shooting incident reconstruction. Trained personnel also enter fired cartridge cases into the National Integrated Ballistic Information Network (NIBIN), which compares evidence from crime scenes with other incidents to identify potential links.