Mass shooting

A mass shooting is a violent crime in which one or more shooters kill or injure multiple persons with firearms. There is no widely accepted definition for mass shooting. Different organizations tracking such incidents use different definitions. Definitions of mass shootings exclude warfare, and sometimes exclude instances of gang violence, armed robberies, familicides and terrorism. The perpetrator of an ongoing mass shooting may be referred to as an active shooter. Mass shootings are most common in the United States.