Lorne L. Dawson, Professor Emeritus, University of Waterloo, Canada.
In public and expert judgements of whether an incident of mass violence by a lone actor is an instance of terrorism or simply mass murder much hinges on determining the relative roles of ideology and mental illness. The more the motivation is ideological the more likely the incident will be classified as terroristic; the more mental illness figures into the etiology of the event the more likely it will be viewed as an instance of public mass murder. Yet as recent and cutting-edge quantitative studies of the perpetrators of both types of attacks are demonstrating, the inclination to engage in such dichotomous thinking is ill-advised. With more and better data in hand, on the pasts and behaviors of those engaging in this violence, the distinction between these types of offenders is blurring, with significant consequences for how we should conceptualize, study, and seek to counter and prevent overall incidents of solo public mass murder.
This paper summarizes and critically analyzes much of the pertinent research literature, delineating the key findings and limitations of this new and expansive field of research, and it lays the groundwork for adopting a dimensional approach to differentiating these different types of solo public mass murderers. This seminar is arranged as part of the research project Violent threats and internal security. Canadian-Swedish bilateral research collaboration on organized violent threats.