Final answer:
Gunshot residue helps investigators by providing forensic evidence that can confirm or refute witness statements and establish a shooter's identity, especially in cases where witness memory may be unreliable.
Step-by-step explanation:
Gunshot residue (GSR) helps investigators in forensic science, which is a crucial aspect of criminal investigations. When a gun is fired, tiny particles from the burning propellant are expelled from the firearm. These particles can settle on the hands, clothing, or surrounding area of the person who fired the weapon as well as the victim. Forensic analysts collect samples, typically with a cotton-tipped applicator, and analyze them using techniques such as scanning electron microscopy (SEM) or inductively coupled plasma (ICP) analysis to detect the presence of GSR.
The information gathered from GSR analysis assists investigators in reconstructing the shooting incident, helping to confirm or refute witness statements, and establish the shooter's identity. This forensic evidence is particularly valuable when witnesses to a crime may have false memories or when their memory could have been influenced by suggestibility, leading to misinformation.