Mass Shooter Leakage and Threats: A Multifaceted Assessment of Motives, Timing, Digital Behavior, and Opportunities for Attack Prevention

When mass shooters engage in leakage or make threats about violence, that creates what a recent NIJ report suggested may be “the best chance for intervention and prevention.” Thus far, however, most research on leakage or threats has not (a) included family and felony mass shootings; (b) explored all dimensions of perpetrators’ leakage and threats: who, what, where, when, why, and how; (c) compared mass shooters who killed four or more victims with less lethal perpetrators or averted shooters across all leakage, threat, reporting, and response variables; or (d) integrated studies of leakage with analyses of shooters’ digital and social media behavior and their “viral” influence.

For the current project, researchers will investigate mass shooter leakage and threats in unprecedented breadth and depth. They will create a rich database of U.S. cases from 2000 to 2023, then conduct at least five original studies to advance understanding of attack-related motives, timing, digital behavior, and opportunities for prevention. This will include (1) quantitative comparisons across mass shooting types and tests of association between leakage, threats, and important life factors, using 30 distinct variables on leakage, threats, public reporting, and responses to reports among approximately 500 public, family, and felony mass shootings; (2) a sequence analysis of the timing of leakage, threats, and intervention opportunities relative to other life events, behaviors, and attack dates, among 100 randomly selected shooters; (3) a quantitative comparison of all leakage, threat, reporting, and response variables between 50 completed and 50 averted shootings; (4) case studies of 50 mass shooters who leaked or made threats online and patterns in other elements of their digital behavior; and (5) statistical tests to analyze relationships for 110 public mass shooters between the (a) occurrence, frequency, type, and mode of their leakage or threats, (b) amount and prominence of news coverage they received, and (c) number of copycat attackers they inspired.

By following a comprehensive dissemination plan to share new empirical findings with scholars, government leaders, subject area experts, threat assessment professionals, law enforcement officers, and the public, this project will empower society to stop more perpetrators in the early stages. More community members will recognize that leakage and threats should not be dismissed as “merely” attention-seeking, that reporting helps potential shooters who want help, and that reporting saves lives. In turn, law enforcement and other authorities will gain the scientific basis they need to respond to leakage and threats more effectively.