A background to Gunshot Residue Analysis

Gunshot Residue Analysis is a key part of many crime scene investigations today where a forearm has been fired. Whenever a firearm is discharged, the primer and the powder detonate inside the cartridge, violently pushing the bullet down the barrel. Most if not all of the explosive gases and particles created by the explosion follow in the bullet's wake. Some of these particles pass through an opening in the firearm. This is very true for revolvers, which has a tendency to leak more gases than semiautomatic firearms.

Gunshot residue is the name given to these chemicals and particles of these gases created from the firing of a weapon. When conducting a clothing analysis or trace analysis many forensic investigators will look for gunshot residue which sticks to the firearm user's hand, arm, clothing, hair, and face. It’s also common for gunshot residue to stick to nearby walls, curtains, furniture and on a victim's clothing and skin particularly in close-up shootings.

Forensic Crime Scene Investigations for Gunshot Residue can often be disrupted by forces including the weather, where wind and rain can alter the pattern of or reduce the spread of the cloud of Gunshot Residue. Gunshot residue (GSR) can be identified by infrared photography under substandard circumstances.

If you require further information on Gunshot Residue Analysis, Firearm Analysis or Trace Analysis please contact Forensic Resources Ltd.