Five of the Chicago serial killer's 33 victims from the 1970s remain unidentified, but the Cook County Sheriff's office is continuing the work to ID them.

In 2003, Steven Mack, a homicide detective with the Huntington Beach Police Department, took a leading role in retrying a twice-overturned murder case against Rodney Alcala. His efforts led to the uncovering of a prolific serial killer.

Amish men are rarely prosecuted and jailed for sexual abuse against children. What's being done to expose these crimes?

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.

The British socialite and Jeffrey Epstein conspirator was sentenced to 20 years in prison for her role in recruiting, grooming and abusing teenage girls over a decade. What made these girls trust her?

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.

On December 4, 1978, Billy Milligan, who was charged with the kidnapping, robbery and rape of three women, became the first defendant found not guilty by reason of insanity due to multiple personality disorder, now reclassified as dissociative identity disorder.

In 1999, Cary Stayner, brother of high-profile abduction victim, Steven Stayner, murdered four females at Yosemite National Park. Where is he today?

Throughout the years, some murderers have turned to the popular classifieds advertisements website to find their victims. Here's why.