Multiple killings by serial or spree killers and the mass violence seen in war crimes and other atrocities have typically been understood as discrete category types, which can foster the view that there are fundamentally different kinds of human beings, including "deviants" who are born evil and innately given to sadism or a callous lack of empathy. In contrast, this book considers the violence of these "deviants" in terms of larger questions about human violence. Therefore, in addition to describing the life histories of a sample of individual serial and spree murderers, the book includes analysis of macro-level phenomena such as genocide, mass rape and killing, and torture occurring under conditions of war, state authorization, or political upheaval. The chief claim of the book is that, given the "right" combination of factors occurring at different levels of analysis, virtually anyone can emerge as a killer or perpetrator of atrocities. While it is crucial to understand individual killers in terms of the details of their biographies, it is equally crucial to understand political atrocities in terms of the details of their histories; and to see that persons and groups are always the product of complexly interacting assemblage processes.