A series of murders in California bear eerie similarities, but police have trouble connecting them -- that is until unique ballistics, mysterious surveillance, and a bloody cell phone lead them to three criminals on a deadly revenge spree.

A series of murders in California bear eerie similarities, but police have trouble connecting them -- that is until unique ballistics, mysterious surveillance, and a bloody cell phone lead them to three criminals on a deadly revenge spree.

The Necktie Killer strikes fear in the hearts of Atlanta's citizens; detectives from neighboring counties piece together correlative clues and distinctive apparel left behind at each crime scene.

The Necktie Killer strikes fear in the hearts of Atlanta's citizens; detectives from neighboring counties piece together correlative clues and distinctive apparel left behind at each crime scene.

A woman's husband is murdered by an intruder wearing a clown mask. After three more victims are killed by a deranged clown, police realize they're dealing with a serial killer.

A woman's husband is murdered by an intruder wearing a clown mask. After three more victims are killed by a deranged clown, police realize they're dealing with a serial killer.

Dallas has its dark side, but nothing compares the horror of a series of women found murdered with their eyeballs surgically removed; a pair of beat cops use their street savvy to lead detectives to a sadistic killer and his bizarre motive.

Dallas has its dark side, but nothing compares the horror of a series of women found murdered with their eyeballs surgically removed; a pair of beat cops use their street savvy to lead detectives to a sadistic killer and his bizarre motive.

In Orange County, Calif., four men are stabbed by a mystery man in a month's time; no one makes a connection to the gruesome double murder of a woman and her son two months earlier except the man sitting in prison for killing his own family.

In Orange County, Calif., four men are stabbed by a mystery man in a month's time; no one makes a connection to the gruesome double murder of a woman and her son two months earlier except the man sitting in prison for killing his own family.

In Alexandria, Va., a sheriff's wife answers the door to a blaze of gunfire, causing the community to buzz with theories; then, more citizens are shot at their front doors, leaving everyone wondering who could be next.

In Alexandria, Va., a sheriff's wife answers the door to a blaze of gunfire, causing the community to buzz with theories; then, more citizens are shot at their front doors, leaving everyone wondering who could be next.

In Bellevue, Wash., a twisted murderer preys on young women leaving their bodies in sadistic poses; as police work to draw crucial connections, an unconventional clue surfaces and leads them to an unlikely killer hiding in plain sight.

In Bellevue, Wash., a twisted murderer preys on young women leaving their bodies in sadistic poses; as police work to draw crucial connections, an unconventional clue surfaces and leads them to an unlikely killer hiding in plain sight.

A monster hunts the streets of Baton Rouge, La., raping and murdering three women; when one brave woman survives a vicious attack, evidence leads police to the hunter.

A monster hunts the streets of Baton Rouge, La., raping and murdering three women; when one brave woman survives a vicious attack, evidence leads police to the hunter.