The manufacturing process uniquely marks firearms, meaning that individual guns can leave distinct marks on any bullets and cartridges fired from them. These marks make it possible to link such evidence back to the originating weapon.
Scientists in the Firearms Unit conduct ballistics examinations to tie ammunition and related components to particular firearms. For example, many valuable items manufactured today, including firearms, have serial numbers die-stamped for identification. When serial numbers are removed and/or obliterated, forensic scientists in the Firearms Unit can utilize a variety of techniques to restore the original serial number.