Montage of some of the deadliest mass shootings that occurred in the United States. Clockwise from top left: The 2017 Las Vegas shooting, the Orlando nightclub shooting, the Virginia Tech shooting, the Sandy Hook Elementary School shooting, and the 2019 El Paso shooting.
Mass shootings are incidents involving multiple victims of firearm-related violence. Definitions vary, with no single, broadly accepted definition. One definition is an act of public firearm violence—excluding gang killings, domestic violence, or terrorist acts sponsored by an organization—in which a shooter kills at least four victims. Using this definition, one study found that nearly one-third of the world's public mass shootings between 1966 and 2012 (90 of 292 incidents) occurred in the United States. Using a similar definition, The Washington Post records 163 mass shootings in the United States between 1967 and June 2019.Mother Jones records 133 mass shootings between 1982 and July 2022. The Associated Press records 59 mass shootings between 2006 and August 2022.
^Bjelopera, Jerome (March 18, 2013). "Public Mass Shootings in the United States"(PDF). Congressional Research Service. Archived from the original(PDF) on September 9, 2013. Retrieved August 26, 2018. There is no broadly agreed-to, specific conceptualization of this issue, so this report uses its own definition for public mass shootings.
^Greenberg, Jon; Jacobson, Louis; Valverde, Miriam (February 14, 2018). "What we know about mass shootings". PolitiFact. Tampa Bay Times. Retrieved February 20, 2018. As noted above, there is no widely accepted definition of mass shootings. People use either broad or restrictive definitions of mass shootings to reinforce their stance on gun control. After the 2012 Sandy Hook school shooting, Congress defined "mass killings" as three or more homicides in a single incident. The definition was intended to clarify when the U.S. Attorney General could assist state and local authorities in investigations of violent acts and shootings in places of public use.
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