Like rifles, shotguns are fired from the shoulder and may release a single projectile. Unlike rifles, however, one pull of a shotgun's trigger may also spray the target with round pellets, or shot. Additionally, the explosive that creates the energy to fire the gun occurs in the fixed shell of a shotgun rather than the metallic cartridge of a rifle.
Per the FBI, shotguns were used in 303 murders in 2012. With 27,000 shotgun recoveries reported to the ATF in 2012, they are the fourth most common type of firearm confiscated at crime scenes.