Examining Pathway-Related Behaviors in Mass Public Shootings: A Large-Scale Empirical Assessment

The Path to Intended Violence framework is widely used to explain the behavioral processes preceding targeted violence, yet pathway-related behaviors have not been systematically examined across large samples. This study provides a large-scale empirical assessment of pathway-related behaviors among individuals who carried out mass public shootings and for whom documented pre-attack warning signs were available. Data were drawn from a multi-source database of 171 incidents involving 175 perpetrators in the United States between 1999 and 2024. Five pathway-related behavioral domains were analyzed for prevalence, accumulation, co-occurrence, variation in documented behavioral combinations, and pathway intensity. Grievance (92.0%) and leakage (85.7%) were highly prevalent, while research and planning (54.3%), preparation (65.1%), and final acts (44.0%) were less common. Most individuals exhibited multiple pathway-related domains, with nearly three-quarters engaging in three or more. Only 22.9% of cases exhibited all pathway-related domains, exceeding expectations under independence and indicating structured overlap. Associations between domains generally were weak to modest, suggesting that pathway-related behaviors do not consistently co-occur across perpetrators in the study. Overall, pathway-related behaviors exhibited substantial variation in their accumulation, co-occurrence, and documented combinations across cases, providing empirical support for conceptualizations of the Path to Intended Violence framework that emphasize flexibility and variation across individuals.