When a gun is fired small particles of firearm discharge residues (FDR) are produced from the bullet and cartridge case of the ammunition.
These residues escape through openings in the gun such as the muzzle and breech, and can be deposited onto the firer, as well as nearby surfaces.
If an individual handles a recently discharged gun or makes contact with an item or surface that has firearm discharge residues on it, this can also result in the transference of these discharge residues to that individual.
When a cartridge is discharged, small particles of Firearm Discharge Residue (FDR) are produced from the cartridge case components of the ammunition and these are primarily composed of both burnt and unburnt particles from both the explosive primer compound, and the propellant material.
It is these particles that are of interest to the Forensic scientist.
FDR can be recovered from the hands, face, nostrils and hair of a suspect by; from their clothing; and from various surfaces, for example from within a vehicle used to transport the suspects, weapons and cartridges after a cartridge has been fired.
Samples taken from a suspect are analysed at a Forensic Laboratory using highly sensitive and complex scientific instruments, and the findings are interpreted and reported. Such reports might be relied upon by the Prosecution.
Our experts can undertake an extremely thorough, and robust assessment of all aspects of the analytical process at the laboratory where the examination took place, as well as the sampling procedures and continuity of the items and prepare a critical evaluation of the FDR evidence.