Mass Shootings In The United States: Population Health Impacts And Policy Levers

The United States is experiencing a gun violence epidemic, and mass shootings are one of its most tragic manifestations. During the past four decades, mass shootings have caused at least 1,000 deaths and another 1,500 injuries in the United States. Although mass shootings account for less than 1 percent of all firearm deaths annually in the country, they evoke significant public interest and have detrimental effects that extend far beyond the harm to the direct victims and their families.

This health policy brief reviews research about mass shootings and their effects on population health. We also discuss policy interventions that may reduce the population health harms inflicted by mass shootings and outline areas for future research. We focus on mass shootings, not the broader phenomenon of gun violence, which is another critical yet distinct issue.

In the 1980s the Federal Bureau of Investigation adopted the definition of a “mass murderer” as a person who kills four or more people, excluding themselves, in a single incident, and typically in a single location. After the 2012 Sandy Hook school shooting, Congress defined the related term “mass killing” to mean three or more killings during a single incident, excluding the perpetrator, without referring to a weapon. With the lack of a firm definition of a mass shooting, researchers rely on different organizations’ definitions and databases to analyze and track mass shootings. The criteria used to create these databases vary by several dimensions, including the minimum victim count, where the incident occurred, whether the shooting was related to a conventional crime (gang violence, robbery, and so on), and whether the perpetrator and the victims were related. These inconsistencies lead to different assessments of the prevalence and lethality of mass shootings.

Despite these differences, most data sets show an increase in the number and lethality of mass shootings between 2000 and 2019 (exhibits 1 and 2). Moreover, there has been greater public awareness of these tragic events in recent years as a result of media coverage. According to a 2019 poll, nearly half of Americans live with the fear of becoming a victim of a mass shooting.

https://www.healthaffairs.org/content/briefs/mass-shootings-united-states-population-health-policy-levers