90 Day Journey: Nicole & Azan

In Chicago, community leader and part-time clown John Wayne Gacy leads a double life, transforming into a monster who preys on male teenagers and becomes the most prolific serial killer of his day.

In Chicago, businessman and part-time clown John Wayne Gacy leads a double life; by day, he is a community leader and helpful neighbor, but, by night, he's a monster who preys on male teenagers as one of the most prolific serial killer of his day.

Charles Manson had the ability to charm and persuade, and he quickly amassed a group of loyal followers who he was able to convince to commit murder.

A serial rapist, who meticulously planned his assaults on women, terrorized Northern California for 27 years before police closed in on a potential suspect.

Wanted for multiple sex attacks against women in Northern California over three decades, this masked predator meticulously planned his assaults by studying the habits and routines of his female prey.

In 1990, Florida police were on the hunt to stop a woman serial killer after the bodies of seven men were found scattered along state highways.

After the bodies of seven men were found scattered along state highways in 1990, Florida police were on the hunt for a woman serial killer.

A killer terrorized Northern California in the late 1960s and taunted the public with cryptic clues. Can new DNA techniques finally unmask this murderer?

Discover if new DNA techniques can finally unmask a murderer who terrorized Northern California in the late 1960s, taunting the public with cryptic clues.

Jim Jones, a charismatic minister turned madman, ultimately led more than 900 followers to their deaths by mass murder-suicide in a South American jungle.

A charismatic minister turned madman, Jim Jones ultimately led more than 900 followers to their deaths by mass murder-suicide in a South American jungle.