Final answer:
Cartridges from revolvers have distinct markings unique to each gun and can be compared to identify the gun it was fired.
Step-by-step explanation:
Cartridges from revolvers have distinct markings that can be compared to identify the gun it was fired. These markings are unique to each gun and are caused by the specific characteristics of the gun's barrel and firing pin. The leaders teach them to be like each other in movement and appearance to maintain uniformity, which also means avoiding any individual behaviors that could break this uniformity. When a bullet is fired, it leaves marks on the cartridge case, such as scratches, grooves, and impressions, which can be examined and compared to the markings on the cartridge case found at the crime scene or in other investigations.