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

An arrogant woman believes she's committed the perfect crime. She is wrong.

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

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.

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 psychopathic son wanting control murders his middle-aged parents.

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 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.

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 vindictive psychopathic wife murders her husband.

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.

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

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.

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.

Every parent's worst nightmare is the possibility that their child has the same evil traits as the most heinous murderers.

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.

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.

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

When a 64-year-old grandmother does not return home from her morning walk, local police uncover that the man responsible for her disappearance is not only a pathological liar but a sexually deviant psychopath carrying out a twisted fantasy.

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.

An obsession with a web-cam model leads to the annihilation of a family.

A prolific serial killer brags on tape about strangling eight young women.

A college student disappears at the start of his freshman year without a trace, leaving his family and his girlfriend reeling; when authorities look to his best friend for answers, they uncover a love triangle gone wrong.