Ballistic toolmarks refer to the unique patterns and characteristics left on a bullet or cartridge casing when it is fired from a firearm. These marks can provide important information to forensic investigators in criminal cases, such as identifying the type of firearm used in a shooting or linking multiple crime scenes to the same weapon.
Ballistic toolmarks are created when a firearm is fired and the bullet or casing is propelled out of the gun's barrel. The marks left on the bullet or casing are unique to the firearm that was used and can be compared to marks left on bullets or casings recovered from other crime scenes or weapons to determine if they match.
Forensic investigators use specialized equipment, such as comparison microscopes and computer databases, to analyze and compare ballistic toolmarks. The analysis involves examining the striations (grooves and ridges) left on the bullet or casing and comparing them to known reference samples from firearms.