Ruthless drug lord Pablo Escobar turns Columbia into the murder capital of the world and may have been responsible for 4,000 to 5,000 murders.
David Berkowitz, aka the Son of Sam, goes on a yearlong murderous rampage killing six people in 1976 and bringing New York City to its knees.
Known as the Boston Strangler, Albert DeSalvo's murder spree claims the lives of 13 women, many of whom he strangled to death with their own nylon stockings.
Police officer turned killer Laurie Bembenek is convicted of murdering her husband's ex-wife, Christine Schultz; Bembenek claims she was framed for the savage murder, but the evidence included her husband's police revolver and fibers from her wig.
In 1966, mass murderer Richard Speck systematically tortures, rapes and murders eight student nurses from South Chicago Community Hospital.
Seemingly average husband and father-of-two Dennis Rader lives a double life as a serial killer who terrorizes the Wichita, Kan., area from the 1970s to the '90s as the self-proclaimed BTK Killer.
For three weeks in 2002, the streets of Washington D.C. are terrorized by 17-year-old Lee Boyd Malvo and 42-year-old John Muhammad who hunt random civilians in broad daylight with a rifle.
John Wayne Gacy, widely thought to be the inspiration for Stephen King's character Pennywise the Clown, murdered 33 young men and teen boys, most of whom he buried in the crawl space beneath his home.
Hitchhiking sex worker Aileen Wuornos garnered national attention after she was charged with murdering at least six men in less than a year by shooting them at point-blank range.
Canadian serial killers Karla Homolka and her husband, Paul Bernardo, drugged, raped and murdered three teens, including her younger sister.