Charles Manson is a violent predator who has powers of persuasion that make it possible for him to convince his hippie followers to brutally murder innocent strangers.

Dr. Michael Swango takes an oath to do no harm, but does just the opposite; suspicious illnesses and deaths follow the once-trusted physician-turned-killer from hospital to hospital for nearly two decades and across two continents.

In 1977, the city of New York is stalked by a seemingly faceless serial killer known as "Son of Sam"; after his final shooting takes him to Brooklyn, a twist of fate and a little luck leads to his capture.

From 1976 to 1977, David Berkowitz terrorizes New York City under his creepy self-given moniker: the "Son of Sam"; he is among the most infamous serial killers in American history.

The Zodiac Killer terrorizes Northern California in the late 1960s; he taunts the public with cryptic clues, threats of violence and ciphers that are supposed to lead to his identity, but mostly go nowhere.

More than 900 Americans died in an isolated jungle in northern Guyana in November 1978; Jim Jones has gone down in history as a madman who drove his followers to suicide, but the truth is more complicated and tragic than that.

More than 900 Americans died in an isolated jungle in northern Guyana in November 1978; Jim Jones has gone down in history as a madman who drove his followers to suicide, but the truth is more complicated and tragic than that.

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, 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 Northern California, a masked predator meticulously plans his sexual assaults by studying the habits and routines of his female prey; after 27 years on the loose, police close in on the man they believe to be the NorCal Rapist.

In Northern California, a masked predator meticulously plans his sexual assaults by studying the habits and routines of his female prey; after 27 years on the loose, police close in on the man they believe to be the NorCal Rapist.

The Zodiac Killer terrorizes Northern California in the late 1960s; he taunts the public with cryptic clues, threats of violence and ciphers that are supposed to lead to his identity, but mostly go nowhere.

The Zodiac Killer terrorizes Northern California in the late 1960s; he taunts the public with cryptic clues, threats of violence and ciphers that are supposed to lead to his identity, but mostly go nowhere.

More than 900 Americans died in an isolated jungle in northern Guyana in November 1978; Jim Jones has gone down in history as a madman who drove his followers to suicide, but the truth is more complicated and tragic than that.

A look at the deal makers and hangers-on who attached themselves to Aileen Wuornos, who is known as America's first female serial killer.

Charles Manson is a violent predator who has powers of persuasion that make it possible for him to convince his hippie followers to brutally murder innocent strangers.

A look at the deal makers and hangers-on who attached themselves to Aileen Wuornos, who is known as America's first female serial killer.

A look at the deal makers and hangers-on who attached themselves to Aileen Wuornos, who is known as America's first female serial killer.

In Northern California, a masked predator meticulously plans his sexual assaults by studying the habits and routines of his female prey; after 27 years on the loose, police close in on the man they believe to be the NorCal Rapist.

Charles Manson is a violent predator who has powers of persuasion that make it possible for him to convince his hippie followers to brutally murder innocent strangers.

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.

Uncovering the dark and twisted motives that led to gruesome killings in the pursuit of a deeper understanding of the relationships behind the horrific killings and of the psychology of the people who committed them.