By  Emily Ann Greene-Colozzi

This dissertation used environmental theoretical frameworks to understand how public mass shooting incidents are impacted by aspects of the crime situation and opportunity. Predatory, public shootings perpetrated by individuals with evidence of mass intent were examined in the United States between 1966 and 2019. This project progressed in several distinct steps with discrete aims: (1) establish an open source database of public mass shooting incidents meeting definitional criteria; (2) perform statistical analysis, including latent class analysis, regression modeling, and structural equational modeling to assess research questions; and (3) perform comparative case studies and crime script analysis to assess situational crime prevention failure or success in eight purposively selected cases. Two research questions, guided by pathway to violence literature, rational choice perspective, and situational crime prevention, were examined: (1) can public mass shooting perpetrators be sorted into meaningful classes according to preparatory and warning signs behaviors?; and (2) how do the built environment and situational guardianship structure of the public mass shooting location influence incident casualties and severity outcomes? Results from this mixed methods study indicate that public mass shooting perpetrators fall into three distinct behavioral classes characterized by different probabilities of warning signs behaviors. Next, there is a protective role of holistic situational crime prevention for mitigating harm of public mass shooting incidents. Protective environmental design exerted a contradictory effect on incident outcomes, mediated by perpetrator and victim behaviors during the shooting. Case studies revealed that failure is often due to human error in implementation of established SCP protocols, rather than a lack of SCP protocols. Implications for prevention and harm mitigation are discussed.

New York: CUNY, 2022. 365p.