Even though public mass shootings are relatively rare, they represent an atypical form of violence that is both sudden and yields an unprecedented amount of carnage; for these reasons, an inordinate amount of scholarship has been produced in order to isolate both the causes and effects of these rampages. As there is no clear cut and universal cause, over the past forty years numerous factors have been offered to account for these types of shootings, including bullying, peer relations, family problems, cultural conflict, demographic change, mental illness, gun culture, copycatting, and the media. While there appears to be an element of truth in each of these perspectives, all of these isolated factors focus upon only one or two surface-level influences, thus ignoring the possibility that multiple and distinct causes are interacting with one another. The aim of this study is to construct a meaningful model of motivation that is common to each situation, is to build upon psycho-social theories of crime, and to highlight which combination of specific background factors and processes is necessary to produce these vicious massacres. To answer the underlying research question, "Why do certain individuals elect this specific line of action?" this thesis will first provide a review of the relevant literature, will then emphasize three key social and psychological predisposers that combine together to negatively influence the individuals involved, and will subsequently highlight five separate and unique case studies in order to examine the proposed model.