PT Mobile Logo

Search form


Mass Shootings: Research and Lessons

Mass Shootings: Research and Lessons

Mass murder—the killing of 4 or more people at one location within one event—is a rare but appalling tragedy. The body of research on mass shootings is relatively small and hampered by the low base rate, questionable methods, and lack of data regarding thwarted events. Mass shootings are not new, but since the 1990s, they have taken on a different quality. This quality has been affected by cultural shift, social media, and enhanced media coverage.

The research

While the existing research is hampered by methodological problems, certain psychosocial factors are consistent (eg, problems with self-esteem, a persecutory/paranoid outlook, narcissism, depression, suicidality, social rejection). The problem of focusing too heavily on these factors is that too many false positives result. The reality is that “no consistent and reliable profile of school shooters exists, and most researchers and clinicians would agree that predicting violent behavior is a slippery slope.”1

In an excellent review of school-associated homicides in kindergarten through 12th grade, Flannery and colleagues1 noted that “a need remains for researchers and commentators to examine other factors beyond the individual that may explain school shootings, including culture, the social ecology of the school, or other community factors.” For example, there are differences between urban and suburban school shootings—some acts are related to threats to the perpetrator’s social identity.2,3 Suburban and rural shootings may be characterized by social alienation, whereas urban incidents may be associated with a general inner-city tolerance of violence. The issues of social marginalization and familial dysfunction are other common findings.4

Lindberg and colleagues5 noted that peer groups played a role in facilitating school shootings; they sought to study whether adolescents who had expressed an online threat of a school massacre differed from those who had expressed a threat offline. Those who expressed their threats online were more likely to have been bullied and depressed, more often made threats with clear intention, and more often were prepared. In contrast, those who expressed threats offline were more likely to have problems with impulse control and to have shown delinquent behavior before the threats.

In another study, Lindberg and colleagues6 attempted to characterize adolescent copycats who had threatened to carry out a school massacre. A majority of these copycats were found to have a history of mental health treatment, depressive symptoms, suicidal ideas, and impulse control problems. The prevalence of pervasive developmental disorders was high.


The assertion that severe mental ill-ness is to be blamed for mass shootings is a distraction. In reality, research shows that “even if one assumes that the association between severe mental illness and recorded violent crime is entirely causal . . . the overall contribution of patients with severe mental illness [is a mere 5%].”7

Given that both prediction and profiling are unhelpful, what are we left with? Most authorities recommend a careful threat assessment approach. The problem is that these endeavors are complicated and time-consuming and need to be done by well-trained professionals working as a multidisciplinary threat assessment team. The process also relies on a thorough psychiatric evalua-tion, which is a resource that is in short supply. Flannery and colleagues1 give the sensible advice that “particular attention should also be paid to a youngster’s access to or fascination with firearms and the presence of writings or drawings with violent themes,” as well as dysfunctional peer relationships, including bullying.

In response to the Sandy Hook tragedy, the Interdisciplinary Group on Preventing School and Community Violence provided a rational set of recommendations.8 The key element of their recommendations is improved communication. Their report states that “the most effective way to prevent many acts of violence targeted at schools is by maintaining close communication and trust with students and others in the community, so that threats will be reported and can be investigated by responsible authorities.” They recommend that schools develop “channels of efficient, user-friendly communication,” so that “community members, students, and staff members feel comfortable bringing concerns regarding safety to the attention of school administrators.”

Third parties, such as other students and family members, may have pre-offense knowledge or significant concerns because potential perpetrators often “leak” their intent. The National Alliance for Mental Illness, which has offices all over the country, is a good resource for friends or family who suspect that a problem is brewing.9,10


Loading comments...

By clicking Accept, you agree to become a member of the UBM Medica Community.