Mass Shootings in Public Places: Continuities and Complexities.

This study examined 71 mass shootings carried out by a single individual who opened fire on random victims in a public setting. Findings indicate that the (all-male) shooters commonly showed signs of anger, isolation, and marginalization. Many were motivated by a perceived grievance. However, among the sizeable group of young White men, extremist, hate-based ideologies often served as motivations. While very few of the shooters had been formally diagnosed, a number had shown signs of mental illness or suicidal tendencies, and close to 30% committed suicide following their attacks. The shooters typically carried out their attacks with semi-automatic guns and high-capacity magazines. Suggested preventative actions included attention to warning signs and gun control measures.