: Scientists look for minute traces of DNA and organic matter inside the firearm's barrel and internal mechanisms.
: By analyzing these biological samples, experts can create a direct link between the physical mechanics of the gunshot and the biological profile of the victim. Series Context
The episode centers on a specialized field that bridges ballistics and molecular biology. When a firearm is discharged at close range, a phenomenon occurs where organic material (such as DNA, blood, or tissue) from the victim is actually into the weapon through the barrel. This "backspatter" provides investigators with a decisive way to prove a specific gun was used in a shooting, even if the exterior of the weapon has been cleaned. Key Investigation Steps
: The team begins with a weapon found at a crime scene. The primary objective is to verify if it is the definitive murder weapon.