Season 9

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

A vindictive psychopathic wife murders her husband.

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.

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.

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.

A young girl disappears, and detectives find a psychopath who duped her.

An impulsive psychopath randomly kills a successful female executive.

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