From German nurse Niels Högel to U.K. doctor Harold Shipman to American nurse Charles Cullen, some serial killers target their patients.

Robyn Maharaj, co-author of 'Grilling Dahmer' with Milwaukee detective Patrick Kennedy, tells us about the late detective's experience with the serial killer.

We speak with author William Rawlings about 'The Stocking Strangler,' a serial killer who raped and strangled women, often with their own stockings, in the 1970s.

We investigate why the Charlotte Police Department took so long to identify 'The Taco Bell Strangler' who targeted Black women in the 1990s.

Serial killer Edmund Kemper, later known as the 'Co-Ed Killer,' was released on parole from Atascadero State Hospital when he was 21 after shooting and killing his grandparents when he was 15. Why did psychiatrists allow him to go free?

The serial killer brought fear to the University of Florida and surrounding area after murdering five young women over the course of three days in 1990.

We speak with author Dawn Keetley to gain insights into the life and crimes of Jesse Pomeroy, the pre-teen who tortured and killed children around Boston in the early 1870s.

What makes a murderer choose one killing method over another? We spoke with experts to gain insight into murder weapon preferences and what they mean.

Serial killer Lonnie David Franklin was arrested in 2010 due to a recovered DNA sample after murdering over the course of about 25 years. Learn about his victims.

In 1996 at Shenandoah National Park, Lollie Winans and Julie Williams were murdered. The case remains unsolved. Journalist Kathryn Miles believes investigators focused on the wrong man.