It’s 1977 and the era of the serial killer begins. LAPD detectives chase multiple killers at the same time. They scour the Hollywood Hills for the Hillside Strangler while hunting the Skid Row Stabber downtown. And then another serial killer emerges...

The Hillside Strangler becomes a media sensation, but Detective Grogan believes it’s two men killing together. Is a woman slain near the beach the work of another serial killer? Detective Lange pursues the Skid Row Stabber to a darkened movie theater.

Kenneth Bianchi is arrested in Washington State, suspected of being the Hillside Strangler. Is his cousin his murder partner? A young girl disappears in Huntington Beach, the victim of a serial killer who appears on the TV show The Dating Game.

Kenneth Bianchi claims he has multiple personalities, and that “Steve” is the Hillside Strangler who kills with a partner. The Dating Game Killer is arrested but proving his guilt will not be easy. Detective Souza begins his pursuit of the Freeway Killer.

While Detective Souza chases the Freeway Killer, he consults with one of the Tool Box Killers. To avoid the death penalty, the Hillside Strangler agrees to testify against his murder partner, Angelo Buono. A new serial killer strikes on the Sunset Strip.

The Sunset Strip Killer leaves a decapitated head for the detectives. The Freeway Killer is sentenced to death and Detective Souza fulfills a promise. The Dating Game Killer is re-tried. The long trial of the Hillside Strangler ends with drama.