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What constitutes a mass shooting?

"Incident that involves multiple victims"
Posted: 4:11 PM, Jun 07, 2021
Updated: 2021-06-07 19:27:45-04
Mass Shootings

(KERO) — It was a deadly weekend for America. Officials reported at least 9 mass shootings across five states highlighting the issue of gun violence in the United States.

A significant portion of that bloodshed happened on the streets of Chicago. Police in the area say there were roughly 34 different shootings where 5 people died.

  • In Cleveland, Ohio, seven people were shot at a graduation party.
  • In Youngstown, Ohio three people were killed and three others were injured in a bar shooting.
  • In Columbus, Ohio a 16-year-old was killed and 5 others injured Saturday night.
  • In New Orleans, Louisiana, eight people were shot at a gathering.
  • In Fort Wayne, Indiana, one person died and three were injured at an apartment complex.
  • In Norfolk, Virginia, four people were injured.
  • In Paterson, New Jersey five people were wounded at a large gathering.
  • In Cumberland County, New Jersey two were killed, and 12 injured at a house party.
  • In North Charleston, South Carolina a 14-year-old was killed, and 13 injured at an "unauthorized" concert.
  • In San Angelo, Texas a 5-year-old boy was one of four people injured in a shooting at a sports complex.
  • In Minneapolis, Minnesota one person was killed, and eight wounded.

With all these shootings happening, you might be wondering what constitutes a mass shooting?

The most accepted definition establishes a mass shooting as any incident that involves multiple victims of gun violence. "Victims" are both people who are killed and those who are injured by gunfire. Typically four people have been injured or killed for the incident to qualify as a mass shooting.

Variation in How Mass Shootings Are Defined

Although there is no official standard for the casualty threshold that distinguishes a mass shooting from other violent crimes involving a firearm, a common approach in the literature is to set a casualty threshold of four fatalities by firearm, excluding the offender or offenders (Fox and Levin, 1998; Duwe, Kovandzic, and Moody, 2002; Gius, 2015c; Krouse and Richardson, 2015; Fox and Fridel, 2016). Using this criterion helps reduce measurement error in identifying mass shootings because fatalities are captured in administrative data and are frequently included in media reports (Duwe, 2000).

However, this categorization is not without controversy. It does not capture incidents in which fewer than four victims were killed but additional victims were nonfatally injured, and it does not include multiple-victim homicides in which fewer than four fatalities resulted from gunshots but additional fatalities occurred by other means.

Thus, many have chosen alternative definitions of casualty thresholds for mass shootings. For instance, Lott and Landes (2000) adopted the definition of two or more injured victims, Kleck (2016) used a six-victim casualty threshold, the Gun Violence Archive (undated-a) defined mass shooting as an incident in which four or more victims (excluding the shooter) are injured or killed, and the Mass Shooting Tracker (undated) set a criterion of four or more people injured or killed (including the shooter).
Gun Policy in America: Rand Corporation

As noted above, the Gun Violence Archive, established in 2013 as "an independent research and data collection organization to provide comprehensive data for the national conversation regarding gun violence," also uses "a purely statistical threshold to define mass shooting based ONLY on the numeric value of 4 or more shot or killed, not including the shooter."

The Congressional Research Service and The Violence Project, which runs the Mass Shooter Database use a threshold of 4 FATALITIES: “a multiple homicide incident in which four or more victims are murdered with firearms—not including the offender(s)—within one event, and at least some of the murders occurred in a public location or locations in close geographical proximity (e.g., a workplace, school, restaurant, or other public settings), and the murders are not attributable to any other underlying criminal activity or commonplace circumstance (armed robbery, criminal competition, insurance fraud, argument, or romantic triangle).”

However, even the more accepted definitions of "mass shootings" are not without their controversy. Some argue that shootings that take place during the commission of another crime should not be considered.

"Because mass shootings that stem from domestic and gang violence are contextually distinct from high-fatality indiscriminate killings in public venues, some analysts have argued that they should be treated separately," explained a report from the Rand Corporation on Gun Policy in America.

The Justice Department is looking at legislation to help curb gun violence. U.S. Attorney General Merrick Garland announced two proposals Monday morning.

One bill clarifies restrictions on turning a pistol into a short-barreled rifle. This comes after similar guns were used in two mass shootings this year.

The second bill would allow family members, law enforcement, and others to petition the court to temporarily prevent a person from having access to firearms. This is commonly referred to as a "Red Flag" law.