Twin Cities, MN, police are hunting for a killer caller who confesses to a string of murders in a chilling, high-pitched voice, begging for forgiveness. No one can identify him until one woman survives a brutal attack.

In the summer of 1976, the NYPD are chasing a man shooting at couples in parked cars with a gigantic, .44 caliber handgun. He taunts the city with terrifying letters until police get a lead about a suspect who has shot a neighbor’s dog.

Brooklyn shop keepers are afraid of closing time as a killer shoots his victims while locking up their stores. Police release surveillance footage to the press and ask the public for help to find a duffle bag wielding murderer before he strikes again.

In the 1990s, New York is on edge as a killer leaves coded clues at crime scenes and declares his compulsion to choose victims by their birth signs. Police race against time before he can achieve twelve killings to complete the Zodiac.

A rash of young men goes missing around Chicago during the 1970s; when bodies start washing up in the river, a pattern emerges; a small piece of evidence leads police to the home of a model citizen, where his furnace puts the suspect in the hot seat.

Police find a string of murdered women in shallow graves in very remote areas of the Alaskan wilderness; after months of searching, police zero in on a local family man living a double life that no one suspects.

Numerous women are found dead by the side of the road with a unique ligature that looks like a dog collar and leash; detectives are stumped until a 17-year-old girl manages an escape from a vicious kidnapper, leading police to a serial killer.

The I-5 corridor in California is taken over by a brazen bandit who terrorizes the highway with a blitz of assaults and murders. The only clue to the identity of the killer is a specific athletic tape used to bind his victims.

A serial killer taunted Wichita, Kansas for decades with brazen letters taking credit for his horrific kills. At the introduction of the computer era, the killer gets sloppy and accidentally leaves a digital clue behind in his final taunt to police.

In the 1990s, Louisiana is terrorized by multiple serial killers. The small-town PD of Zachary discover the key to solving their cases when a pattern emerges with personal items missing from each local victim.