Infographic: Mass Shootings in the United States, 1982-Present

A mass shooting, also called an active shooter incident, is defined by the U.S. Federal Bureau of Investigation (FBI) as an event in which one or more individuals are “actively engaged in killing or attempting to kill people in a populated area. Implicit in this definition is the shooter’s use of a firearm.” The FBI has not set a minimum number of casualties to qualify an event as a mass shooting, but U.S. statute (the Investigative Assistance for Violent Crimes Act of 2012) defines a “mass killing” as “3 or more killings in a single incident.” For the purposes of this article, both sets of criteria will be applied to the term mass shooting, with the distinction that the shooter or shooters are not included in any fatality statistics.

Mass shootings have exacted a deadly toll on communities across the United States. According to statistics compiled by Mother Jones magazine, more than a thousand people have been killed in such attacks since 1982. American society is deeply divided on the issue of gun control, however, and these events have only intensified the debate. In the wake of the Sandy Hook Elementary School shooting in 2012, some, including Pres. Barack Obama, called for a renewed ban on assault weapons and for tighter background checks. Others, chief among them the National Rifle Association, resisted any gun restrictions as an unacceptable infringement on the Second Amendment. In the decade following the Sandy Hook shooting, some states enacted restrictions on high-capacity magazines, but no meaningful gun control legislation was passed at the federal level.