In Trigger Points,  Mark Follman traces the evolution of behavioral threat analysis—from Dr. Robert Fein and Dr. Shervert Frazier's startling interviews with the criminally insane at Boston's Bridgewater State Hospital in the 1970s to the stalking behaviors discovered by FBI agents in the aftermath of John Lennon's 1980 assassination to the barrage of mass shootings that began, in earnest, with Columbine in 1999 and culminated in research that revolutionized the field of analysis and deepened in more recent years following the events of Sandy Hook, Las Vegas, and Stoneman Douglas. Although each event is unique in size and scope, Follman shows how the the branch of forensic psychology originating in the FBI’s research on serial killers and stalkers was eventually modified to predict the violence brewing within members of our communities. Weaving panoramic storytelling with fresh investigative insights, Trigger Points offers hope and a way forward at a time when the costs of failing to prevent gun violence have never been higher.