Homicide is as old as human existence and, likewise, mass murder and serial killings are not recent phenomena. Having adopted formal definitions in the 1980s’s both mass murder and serial homicide are often mistakenly equated; however, the two phenomena are distinct as evidenced by wider patterns of violence, victimization, and psychopathology. This chapter provides an overview of mass murder and serial homicide including definitions and selected case studies. Seeking to clarify the distinctions between perpetrators of mass murder and serial homicide, this chapter also provides information on the psychopathology of each type of offender and provides a brief examination of the developmental experiences and victim choice of the perpetrators.

Selective enforcement and people’s community continued to order offenders and punishments until the bloody end. Widespread defiance during the invasion of Allied forces shook radicals. Himmler had to intervene when security services defied the HSSPF over unsanctioned orders to execute Aryans. Mass arrests and forced evacuations sufficed instead. Mass releases followed as counterattacks relieved pressure. The security services decentralized authority to avoid the same problem during the new year. A regional triumvirate maintained legitimate oversight with joint orders of execution. Punishable offences became death sentences and imprisonment served as a warning. Most Germans were released, and most foreigners were murdered. An epilogue traces how the Gestapo Leader Gerhard Dahmen presented selective enforcement as resistance from within the system during denazification. The main conclusions link this to how a predictable criteria of political reliability grounded in people’s community allowed targeted persecution to be presented as a public good. A mutually reinforcing dynamic of popular support and terror targeting socio-political outsiders legitimized dictatorship.