Dunblane 1996. Columbine 1999. Utøya 2011. Christchurch 2019. Lewiston 2023.What drives someone to commit the unthinkable? In Running Amok, forensic psychiatrist Paul E. Mullen burrows into the minds of lone wolf mass murderers, exposing the troubling patterns underlying their actions.Drawing on decades of first-hand experience assessing killers such as Australia’s Martin Bryant and Anders Breivik, Mullen examines the key forces that unite them: obsessive rage, personal grievance, a fascination with weapons and a destructive quest for infamy – often culminating in suicide. Mullen challenges myths about madness and violence, revealing these killers not as incomprehensible monsters, but as deeply disturbed individuals shaped by knowable forces. Crucially, he offers guidance for recognising warning signs and improving threat assessment.Running Amok is both a searing investigation into mass murder and a call to action, urging society to confront these dark realities and prevent the next horror.