The timing of opportunities to prevent mass shootings: a study of mental health contacts, work and school problems, and firearms acquisition

Abstract

Although it is important to know what public mass shooters have in common, it is also helpful to understand when different variables were present on their pathways to violence. This study explored the timing of key life events for the deadliest public mass shooters in the United States since Columbine (N = 14). Using data from official reports and supplementary sources, we found perpetrators’ mental health contacts often began more than a decade before their mass shootings, and often ended more than a year before their attacks. Mental illness was typically a constant in their lives, not something that automatically caused them to attack. While treatment may help prevent some mass shootings, mental health professionals have limited influence over patients they have not recently seen. In turn, perpetrators’ work and school problems also typically began long before their mass shootings, but these issues continued closer to their attacks. Employers and educators may therefore have an opportunity to intervene later in the process. Firearms acquisition often occurred in the final stages, after perpetrators were already interested in mass murder. Red flag laws and ERPOs which prohibit sales to explicitly dangerous individuals may therefore help reduce the prevalence of these attacks.

Keywords:

• Public mass shootings
• mental illness
• work or school problems
• firearms
• violence prevention

Disclosure statement

No potential competing interest was reported by the author(s).

Notes

1 For some variables (such as use of psychiatric medication), comparisons between public mass shooters and the general population might benefit from controlling for perpetrators usually being male.

2 The 14 qualifying cases were as follows: the 1999 Atlanta day trading murders, 2007 Virginia Tech shooting, 2009 Binghamton shootings, 2009 Fort Hood Army base shooting, 2012 Aurora movie theater shooting, 2012 Sandy Hook school shooting, 2013 Washington, DC Navy Yard shooting, 2016 Orlando nightclub shooting, 2017 Las Vegas shooting, 2017 Sutherland Springs church shooting, 2018 Parkland school shooting, 2018 Thousand Oaks shooting, 2019 El Paso shooting, and 2019 Virginia Beach shooting. We did not include the 1999 Columbine shooting or the 2015 San Bernardino shooting because they involved co-perpetrators who attacked together. This is very rare in public mass shootings—more than 95% of incidents involve a single shooter attacking alone (Peterson & Densley, 2019)—and the intermingled nature of co-perpetrators’ lives may be fundamentally different from the lives of single attackers. In a few cases, public mass shooters killed victims shortly before their mass shooting, and we included these victims in the total count.

3 Although this study focused on the deadliest public mass shooters, we were not trying to explain what factors cause some perpetrators to kill more victims than others, nor what differentiates highly lethal mass shooters from less lethal ones.

4 For some perpetrators, their first mental health contact or first firearm acquisition was also their last mental health contact or last firearm acquisition, but this was not the case for any perpetrators regarding their work or school problems.

5 In some cases, public mass shooters exhibited symptoms of mental illness but were not formally diagnosed. Post-attack mental health contacts (e.g., assessments in jail or prison) were not included.

6 Two variables can only be sequenced if both were present in a perpetrator’s life. These proportions were calculated based on the 12 perpetrators with at least one mental health contact and the 13 perpetrators with at least one work or school problem. All shooters acquired firearms, of course.

7 Our study’s finding that 50% of the deadliest public mass shooters were prescribed psychiatric medication is substantially higher than Peterson and Densley’s (2019)’s finding of approximately 20% for public mass shooters in general. Two potential explanations are that (a) this is a fundamental difference between the deadliest perpetrators and less deadly ones, and/or (b) this difference is attributable to more data availability for the deadliest perpetrators and more missing information for less deadly ones.

8 This could also be interpreted as evidence that A.A. failed to “cure” these individuals, but for some people, treatment does not yield a quick, permanent solution. For them, it is important that treatment be sustained—in some cases, for a lifetime.

9 In the United States, men are significantly more likely than women to avoid doctors (O’Hara & Caswell, 2013) and to own firearms (Pew Research Center, 2017).