Goofs

The detectives sometimes pick up a weapon with a handkerchief or by inserting a pencil in the barrel. In real life, the handkerchief might contaminate possible DNA evidence, and the pencil would destroy microscopic markings inside the barrel, making it difficult to match the weapon to slugs retrieved from a victim's body or a crime scene. Instead, one expert recommends holding a weapon in place with gloved fingertips and sliding a thin, stiff sheet of plastic beneath it. See more