Similarities between copycat mass shooters and their role models: An empirical analysis with implications for threat assessment and violence prevention

Background

Although an important subset of mass shooters has admitted copying previous shooters, there has been almost no empirical research on the similarities between mass shooting role models and their copycats. Such analysis is essential for understanding who is most susceptible to the influence of high-profile mass shooters and what behaviors they are likely to copy.

Methods

We first compiled all documented instances we could find globally of public mass shooters and active shooters becoming a role model for a copycat from 1966 to 2022 (n = 205) and calculated how often their risk profiles and behaviors were similar. Next, we ran simulated matches (n = 2000) and used binary logistic regression to test whether copycats were significantly more similar to their role models than to a random shooter.

Findings

Compared to a random shooter, copycat attackers were significantly closer to their role models in age and more likely to share the same sex, race, country, incident location type, and offender outcome. Nearly 80% of copycats attacked more than one year after their role model, and the average temporal gap was approximately eight years. Copycats averaged significantly fewer victims killed and wounded than their role models.

Conclusions

The risk that high-profile mass shooters influence copycat attackers persists for many years, with the most susceptible individuals sharing characteristics of the role model shooters themselves. These findings could be used to make media coverage of mass shootings safer and to inform triage and case prioritization for threat assessment and violence prevention.