What is one of the main components found in gunshot residue?

Gunshot residue (GSR) is primarily made up of small particles that result from the discharge of a firearm. One of the main components of gunshot residue is lead, which originates from the primer and, in some cases, the projectile itself. When a firearm is discharged, the primer contains lead compounds that are expelled into the air, creating tiny particles that can settle on the shooter and nearby surfaces. The presence of lead in GSR is significant in forensic investigations, as it can be used to determine if an individual had discharged a firearm, handled a firearm, or was in close proximity to one when it was fired.

Other components of GSR may include barium and antimony, which are also found in primer mixtures, but lead remains a primary indicator due to its prevalence in traditional ammunition. This is why recognizing lead as a major component of gunshot residue is critical in forensic trace evidence analysis. An understanding of this composition is essential for evidence technicians when they are collecting and analyzing samples in criminal investigations.