When a gun is recovered from a crime scene never touch the blank with hands or any other object so you don't accidentally discharged the weapon

When an investigator processes and reconstructs a crime scene where shots were fired, determining who may have shot the firearm may be critical to the case. The lab may be able to assist with such investigations through the use of gunshot residue (GSR) analysis. GSR is typically expelled from a firearm upon discharge and can land on individuals in close range of the firearm. GSR kits are designed to collect these particles, and the Trace evidence section of the lab has the equipment and expertise to analyze these kits. While GSR testing can provide important information for your case, there are limitations in what the results indicate in a shooting incident.

i'm assuming that the correct answer is indeed the first one/ "a"..

i have no clue hope you find the answer