The procedure used by firearms and ballistics experts involves external investigation of an examination item and checking the operation of all its mechanisms, followed by firing an item at experimental shooting range to a bullet trapper or tube (barrel) filled with water in order to recover cartridge cases and bullets. Consequently, these are subject to microscopic, comparative examinations with relevant items from the National Collection of Bullets and Cartridge Cases.

An examiner investigates individual construction features, operation mechanism and ballistic properties of a firearm. During this process, experts utilise in situ collection of more than 3000 firearms, including manufacture-made, home-made and the so-called “concealed” (e.g. shooting pens or pipes) firearms, as well as ammunition collection. Examination is supported by essential measurement instrumentation, including photo-optical gates and Doppler radar for bullet velocity measurements, Trigger Scan for measurement of trigger pressure and special chamber for firing gas pistols.

A number of marks and damages are formed as a result of shooting. Experts consider various cases of gun-shot damages depending on the type of firearms or bullet, target and shooting distance.

„LINIA” device is used for determination of bullet trajectory from a shooting point to the target. “LINIA” employs a laser, emitting two beams running in two opposite directions. Such examination is used, among others, for verification of versions of event, elimination of suspects, verification of testimonies provided by witnesses and suspects, typing of incident-related persons and finally, pointing to a circumstantial evidence.

Bullets and cartridge cases found at crime scenes are stored in dedicated, forensic collection and used for searching against other bullets and cases from various scenes of crime or firearms used in shooting incidents. To this end, experts utilize mainly microscopic and macroscopic optical instrumentation and automated search performed by Automatic System of Ballistic Identification – ARSENAL.

In line with the Regulation of the Minister of Interior and Administration of April 24, 2004 on weapon decommissioning, experts endorse technical specification and verify correctness of firearms decommissioning procedure.