A frantic graduate student calls 911 to say she just shot her boyfriend in self-defense. Police soon discover that her story doesn't add up and realize they are face-to-face with a remorseless, calculating psychopath.

Eleven operators receive a terrifying call from a youngster who claims he stabbed his parents to death. Unsure if the call is a Halloween joke, police rush to the area, only to learn that it is not a fake and that the caller is a budding psychopath.

A teen plays out his sadistic fantasies of murder on an unassuming drifter.

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.

In rural Missouri, police receive a chilling call from a 50-year-old man who claims to have shot three individuals inside his home. Detectives discover that this impulsive massacre had a purpose, and that the culprit is a psychopath obsessed with control.

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.

A road rage incident turns deadly as an elderly man is beaten to death by a teenager who claims he was acting in self-defense. Detectives not only find holes in his story but uncover that he is a remorseless and utterly manipulative psychopath.

A mother awakes to find her two sons with their throats cut. Their aunt's boyfriend confesses to his mother, and she wears a wire to capture her son. As he admits his guilt, it's clear how a psychopathic rage led to horrific violence and innocent victims.

Experts explore cases of psychopathic killers known as family annihilators.