The strong association between firearms, domestic violence (particularly intimate partner homicide), and additional victimization suggests that prioritization of measures to decrease access to firearms to perpetrators of domestic violence may also reduce the incidence of mass shootings. The majority of mass shootings are associated with domestic violence. The current study by Kivisto and Porter examines whether the use of a firearm in domestic homicide affects the risk that others will also be killed during the same incident. Earlier studies have demonstrated that domestic homicide often extends to additional victims linked to the primary perpetrator or victim, either through a preexisting relationship or through physical proximity to the violence. Based on a national surveillance database, Kivisto and Porter confirm findings from earlier, more limited studies. Firearm use is associated with an increased incidence of multiple homicide victimization, especially in domestic situations. This suggests that additional laws to prevent those who perpetrate domestic violence from purchasing or possessing firearms, and vigorous enforcement of new and existing laws, may decrease the incidence of mass shootings, whether additional victims are inside or outside the home.
The study by Kivisto and Porter, “Firearm use increases risk of multiple victims in domestic homicides,”1 examines whether the use of a firearm in domestic homicide affects the risk that others will also be killed during the same incident. Firearms are the most commonly used weapon in all homicides, including intimate partner homicide. As Kivisto and Porter acknowledge, earlier studies have demonstrated that domestic homicide “frequently extends to additional victims linked to the primary perpetrator or victim, either through a preexisting relationship or simply through physical proximity to the violence” (Ref. 1, p 1). Their current findings, the first based on a national surveillance database, confirm what earlier, more limited studies have suggested: “Firearm use is associated with an increased incidence of multiple homicide victimization, particularly in domestic situations” (Ref. 1, p 8).
Most people think of a mass shooting as an incident with multiple fatalities in which a lone gunman opens fire on random people in a public space. When domestic homicides involving intimate partners and other family members are confined to a residence, they may not be considered or counted as a mass shooting. Nevertheless, between 2009 and 2018, at least 54 percent of mass shootings, defined as shootings in which more than three people are killed in one event, were related to domestic or family violence.2
Prohibiting firearm access for those with a history of domestic violence has proved effective in reducing rates of intimate partner homicide. This suggests that, in the context of domestic violence, identifying additional areas where prohibition might decrease access to firearms and effectively enforcing restrictions that already exist may also decrease mass shootings, both inside and outside the home. That the study by Kivisto and Porter1 is the first to demonstrate the national scope of the intersection between domestic homicide and mass shootings underscores the challenges in gathering basic research data regarding mass shootings as well as domestic violence.