Pre-attack crisis indicators in mass shooters: Differences across no-, single-, and dual-harm groups

Area of Science:

• Psychology
• Criminology
• Public Health

Background:

• Mass violence perpetrators often exhibit psychological distress before attacks.
• Previous research linked self- and other-harm histories to adverse outcomes.
• The crisis indicator framework has not been applied to mass shooters.

Purpose of the Study:

• To examine crisis indicators among U.S. mass shooters.
• To classify shooters into distinct profiles based on crisis indicators.
• To assess the utility of a harm-based framework for risk identification.

Main Methods:

• Analyzed data from 197 U.S. mass shooters (1966-2023) from The Violence Project Database.
• Classified participants into no-harm, single-harm, and dual-harm groups.
• Conducted latent class analysis (LCA) on nine pre-shooting crisis indicators.

Main Results:

• One-third of shooters had suicidality history; over half harmed others; 20.3% were dual-harm.
• LCA identified four classes: Depressed/agitated, No-crisis, Psychotic symptoms, and Emotionally labile/aggressive.
• The dual-harm group was overrepresented in the "Emotionally labile and aggressive" class.

Conclusions:

• Mass shooters display diverse crisis indicators and can be categorized into distinct profiles.
• A harm-based framework (no-harm, single-harm, dual-harm) may aid in identifying acute risk.
• Identifiable crisis signs in many individuals underscore the need for tailored prevention strategies.