Death row inmate John Hummel agrees to a final interview weeks before his execution.

An early morning fire inside an apartment complex reveals the dead bodies of a young woman and an infant boy.

A 19-year-old woman vanishes, and the suspect is a former high school classmate with whom she had been communicating days earlier. The family is weary, for the suspect has a notorious past filled with sexual deviancy and homicidal urges toward women.

A vindictive psychopathic wife murders her husband.

Police catch a break on three St. Louis cold case murders when emerging DNA technology makes a match: a 73-year-old frail man whose harmless facade is hiding a vicious individual.

A young man's confession to participating in a plot to murder another teenager stuns police of Ocala, Florida. As detectives dig in, they uncover a sadistic plot involving a manipulative ex-girlfriend with the desire to kill.

When a young mother goes missing, her husband joins the search while police discover her dismembered body in a stack of bins.

Hikers in Portland discover the badly decomposed body of a raped and strangled young girl. A month later, another woman turns up brutally murdered in same fashion. The prime suspect is a homeless drifter harboring dark sexual fantasies.

A psychopathic son wanting control murders his middle-aged parents.

After a couple's murder, police find a fantasy killing by two psychopaths.

Terror rocks an Ohio town when a mother, her two kids, and a close friend vanish. Fearing foul play, investigators track down the prime suspect and uncover a house of horrors. Detectives find themselves dealing with a psychopath with a bizarre obsession.

A husband becomes the prime suspect when his wife goes missing as police discovers his checkered past; lacking a body or evidence of foul play, detectives hope to gain a confession from a man they realize might be a cold-blooded psychopath.

Experts explore the anatomy of the key manipulative tactics of psychopaths.

A man finds his girlfriend and her mother murdered in their beds at night; he calls 911 for help, but police discover his urge to seek revenge.

A killer shoots a young woman dead in her boyfriend's Orlando apartment. Hours later, he turns up in a hospital bed 500 miles away with a gunshot wound and a bizarre story that unravels to reveal he's a lying, callous psychopath.

A 33-year-old oil rig worker calls 911 to report his girlfriend missing. He seems to be helping in the time-critical hunt to find her. A failed polygraph test leads detectives to suspect this seemingly caring boyfriend is a psychopath.

A 911 operator receives a frightening call from a man who claims that he stabbed and killed two people. Police rapidly learn that not only is the call legitimate, but the caller is a violent and unpredictable psychotic.

Weeks after an 18-year-old man's friend reports him missing, his clothing turns up burned in a trash can behind a suburban home. When witnesses lead investigators to a young man with a history of violence, they soon learn he had not worked alone.

A man finds his family slaughtered in their West Virginia home. The oldest son, 16-year-old Gavin Smith, is missing, he turns up hiding at his girlfriend's.

For over three decades, Albuquerque police struggle to solve three violent cold cases. After years of searching, the cases break wide open when officers pick up a man on a probation violation. and he soon reveals himself to be a homicidal psychopath.

When police question a man in his pregnant ex-girlfriend and her young son's disappearance, they discover he has a terrifying capacity for violence. Later, a seemingly innocuous man searching for a missing girl could be a real-life monster.

A missing Colorado woman's roommate claims she'll do anything to help find her, but investigators fear they may have a rare female psychopath on their hands. Later, a killer's angry outbursts could be real, or just an act put on by a manipulator.

A concerned mother reports her 24-year-old son missing. He has fallen under the spell of a 47-year-old widowed woman. Detectives soon realize she's a sexual psychopath who has claimed the lives of more than one admirer.

After his wife vanishes from Jackson, Missouri., a psychopath plays cat and mouse with detectives.

Six months pregnant Martine Bernard's family reports her missing, days later, her father vanishes as well. When officers interview Martine's husband, Cassandritz Blanc, they find a calculating psychopath willing to do anything to cover his tracks.