LegiStorm

Summary:

There is no single, widely accepted definition of a mass shooting. Instead, there is a group of numerous, disparate, and uncoordinated definitions of a mass shooting. Various entities, however, have offered related definitions. For instance, the Federal Bureau of Investigation (FBI) defines “active shooter incidents,” and since 2000 has reported annually on active shooter incidents that meet “the federal definition of ‘mass killing’.” These are the closest concepts to mass shootings offered by federal law enforcement and require consideration of the status of the incident when it becomes known to law enforcement, the context in which the shooting occurs, and the number of fatalities. Active shooter incidents are those where “individuals [are] actively engaged in killing or attempting to kill people in a confined and populated area” involving the use of a firearm where the incident is ongoing and thus has “the potential for a response to affect the outcome.” Active shooter incidents that meet the federal standard for mass killings have at least three fatalities in a single incident, not including the shooter. If the police are notified of the incident after it has concluded or the event occurs in a sparsely populated public place, then it is not considered by the FBI to be an active shooter incident. Incidents resulting from selfdefense, gang violence, drug violence, domestic or residential disputes, hostage situations, or crossfire as a byproduct of another ongoing criminal act, as well as acts that do not put other people in peril, are also not considered active shooter incidents. In its report Active Shooter Incidents in the United States in 2023, the FBI identified a total of 40 active shooter incidents that resulted in a mass killing between 2021 and 2023. In contrast to the FBI’s definition, nongovernment organizations have defined mass shootings in various ways. For example, the nonprofit organization Gun Violence Archive (GVA), which attempts to track every reported incident of gun violence in the United States using publicly available sources, defines a “mass shooting” as an incident where there is “a minimum of four victims shot, not including any shooter” (the definition is agnostic to the number of fatalities). Using this definition, the GVA counts 1,965 separate mass shootings during the same period examined by the most recent FBI report (2023) on active shooter incidents. The arguments given about what should and should not be included as requirements to define incidents of firearm violence as a mass shooting involve three primary questions: • Should there be a minimum number of fatalities or casualties, and if so, what number should be used? • Is the shooting itself an end goal for the perpetrator or does it occur within the context of a broader crime, such as armed robbery or drug trafficking? • Should incidents involving domestic violence and familicide be considered mass shootings, especially if the incidents occur in a perpetrator’s or victim’s private residence? Members of Congress consistently face calls to combat mass shootings. Without a clear method of defining the phenomenon, this can lead to different understandings of scope, imprecise and ineffective responses, and faulty measures of effectiveness. If mass shootings are defined too narrowly, it may be difficult to identify the shared contributing characteristics of the incidents that could be addressed by policy changes. If mass shootings are defined too broadly, any policy considerations may have to be broad enough to address a wide array of contributing characteristics associated with these incidents. Congress may debate the tradeoffs of adopting a definition of mass shootings narrowly, broadly, or at all. If policymakers choose to define what constitutes a mass shooting, they may also consider whether to adopt a single definition or multiple definitions that may cover specific types of shootings.