didn't you just cite a mainstream media outlet??

Posted on: August 7, 2019 at 08:52:55 CT

In the 1980s, the Federal Bureau of Investigation (FBI) defined mass murderer as someone who “kills four or more people in a single incident (not including himself), typically in a single location” (Krouse and Richardson, 2015). However, the government has never defined mass shooting as a separate category, and there is not yet a universally accepted definition of the term. Thus, media outlets, academic researchers, and law enforcement agencies frequently use different definitions when discussing mass shootings, which can complicate our understanding of mass shooting trends and their relationship to gun policy. The table below provides examples of the variation in the criteria set by five of the most commonly referenced data sources on mass shootings in the United States.

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 adopt the FBI’s criteria for a mass murderer and set a casualty threshold of four fatalities by firearm, excluding the offender or offenders (Duwe, ­Kovandzic, and Moody, 2002; Krouse and Richardson, 2015; Gius, 2015c; Fox and Fridel, 2016). However, this categorization is not without controversy. It does not capture incidents in which fewer than four victims were killed but additional victims were 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. Additionally, the FBI classification of mass murderer was established primarily with the aim of clarifying criminal profiling procedures, not for the purpose of data collection or statistical ­analysis (Ressler, Burgess, and Douglas, 1988). 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, 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 Mass Shooting Tracker (undated) set a criterion of four or more people injured or killed (including the shooter).