The Firearms Unit compares marks left on spent bullet casings and projectiles to those on samples fired from confiscated weapons. In addition, residue left on body parts or textiles after a weapon has discharged – so-called gunshot residues – can be identified using chemical methods. Together with findings from shooting scene reconstructions, a complete picture of the sequence of events can be revealed.

Under the direction of the Swiss Police Chiefs Association (KKPKS), the FOR maintains the headquarters (ZSAS) for matching open cases involving firearms both nationally and internationally.