Currently Available Full Episodes

Summer of Fear

S3/EP10 |
Aired: 11/07/2021
Chaos descends on Phoenix as two serial killers compete for the media���s attention and the bodies pile up faster than the police can investigate. 1:25:48

Deaths in the Desert

S3/EP9 |
Aired: 10/31/2021
El Paso investigators race to track down a ruthless killer that is burying his victims in shallow desert graves, dead or alive. 43:54

The Tourniquet Killer

S3/EP8 |
Aired: 10/31/2021
A Houston killer taunts the media and authorities as he uses homemade ligatures to murder his victims. 43:54

The Grim Sleeper

S3/EP7 |
Aired: 10/24/2021
A cold blooded killer conceals his victim���s bodies with trash, discarding them like garbage in the back alleys across Los Angeles. 43:54

The Interstate Killer

S3/EP6 |
Aired: 10/17/2021
A killer crisscrosses the Midwest leaving a string of victims along the interstate. When investigators are hot on the highway killer’s trail, the murderer suddenly changes his mark. 43:54

Classified to Kill

S3/EP5 |
Aired: 04/16/2021
Chicago detectives believe a serial killer is using the classified ads to lure and murder his victims. The investigation is set ablaze when flames obliterate evidence, until police make a shocking discovery. 43:54

Latest Clips

Phoenix Police Realize Serial Shooter Is on the Loose
Preview
1:51
Mark of a Serial Killer

Phoenix Police Realize Serial Shooter Is on the Loose

S3/EP10 A police officer from Tolleson, a tiny town near Phoenix, contacted the city���s police department to reveal a similar shooting had occurred in his area. Could it be the same person?
The Baseline Killer Stalks Phoenix
Preview
1:59
Mark of a Serial Killer

The Baseline Killer Stalks Phoenix

S3/EP10 Police used a national database to determine the same gun used to murder Tina Washington was connected to other cases ��� cases involving a criminal known as the Baseline Rapist.
Serial Shooter Victim Gives Vital Clue
Preview
2:24
Mark of a Serial Killer

Serial Shooter Victim Gives Vital Clue

S3/EP10 As Phoenix was terrorized by two serial killers in the summer of 2006, a victim of the Serial Shooter managed to survive and give police important information about the killer.
Why Did the Tourniquet Killer Stop?
Exclusive
1:23
Mark of a Serial Killer

Why Did the Tourniquet Killer Stop?

S3/EP8 After four women were found strangled to death in Houston, the serial killer behind the murders seemingly stopped. Police had potential theories why that was.
Tourniquet Killer Seemingly Contacts Media
Exclusive
1:35
Mark of a Serial Killer

Tourniquet Killer Seemingly Contacts Media

S3/EP8 A reporter recalls the anonymous call made to the Houston news station in 1995, where the caller told her details about where to find the body. “I knew I was talking to the killer,” she declares.
License Plate Clue Emerges in ‘Grim Sleeper’ Murders
Exclusive
2:27
Mark of a Serial Killer

License Plate Clue Emerges in ‘Grim Sleeper’ Murders

S3/EP7 On January 10, 1987, a witness called 911 to report a man disposing of a body in an alleyway. He was able to give authorities a description of the car and the license plate number — was this the break they needed?
Women’s Bodies Found in L.A. Alleys
Exclusive
1:20
Mark of a Serial Killer

Women’s Bodies Found in L.A. Alleys

S3/EP7 Starting in 1985, women were found dead in alleys in Los Angeles, typically covered in trash. Here’s why investigators thought the killer discarded bodies like that.