How one serial killer wreaked havoc in California and changed the nation's laws. Everything from rape crisis centers, to 911 emergency services and DNA collection laws were influenced by the Golden State Killer. Yet, for 40 years the perverse predator has evaded capture. In 2016, however, law enforcement and the FBI launched a massive nationwide manhunt and are hot on his trail.

Investigators analyze the evidence and explore the various theories as to who this ruthless barbarian could be, including what job could have afforded him the time to commit his heinous crimes; where he may have lived; and how he managed avoid detection.