Blurred Boundaries of Lone-Actor Targeted Violence: Similarities in the Genesis and Performance of Terrorist Attacks and School Shootings

Over the past 5 years, Europe has witnessed an increasing number of attacks by lone actors, whose definition and classification presents challenges to the existing premises of violence research. These cases appear to combine elements from both rampage killings (school shootings) and terrorism. Research has to date treated school shootings and lone-actor terrorism as distinct phenomena, although no clear and unequivocal definitions have been formulated for either. In terms of execution and developmental path, school shooters and lone-actor terrorists appear to have a great deal more in common than previously thought. Against the background of the current state of research, we derive hypotheses about the differences and similarities in the genesis of both phenomena. In relationship to execution, this applies to the planned mode of assassination and the communicative significance attached to both phenomena. In connection with the development path, we find that similar processes of progressive cognitive transformation (toward a polarized and violent interpretative framework) occur in a context of experienced grievances and crises, whereby both groups tend to exhibit functional processing of reality. Processes of identification with biographically and culturally compatible worldviews and interpretative frameworks lead to a redefinition of the perpetrator's self-concept, and in turn to cognitive escalation and changes in behavior. The path toward violent action is supported by social mechanisms arising out of the necessity to keep this cognitive and behavioral escalation process secret. Finally, similar trigger events are observed for both phenomena. In this context, we describe school shootings and acts of terrorism as demonstrative targeted violence.