The creation of the federal "Supermax" prison in Colorado, and its use of solitary confinement, was the result of the actions of inmates Thomas Silverstein and Clayton Fountain.

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.

Mona Gable, author of 'Searching for Savanna,' spoke with us about LaFontaine-Greywind's murder, and how it sparked progress in ensuring justice for missing and murdered Native American women and girls.

Aside from the emotional pain and physical injury it causes, bullying among kids can also result in death. Young bullies have murdered their victims. Bullying at school has also led to some victims lashing out and killing.

The Baton Rouge serial killer murdered eight women in Louisiana between 1994 and 2004, around the same time serial killer Derrick Todd Lee was also active in the area.

Susan Jonusas talks to us about her book 'Hell's Half-Acre' about a 'family' of four known as the 'Benders,' who were accused of murdering 11 people in Kansas but fled before they were prosecuted.

Read about the life and death of Tim McCoy, serial killer John Wayne Gacy's first known victim. Gacy murdered at least 33 boys and men between 1972 and 1978

During the 1990s and early 2000s, more than 30 women were targeted by serial killers, including Derrick Todd Lee, in the Baton Rouge area.

Dr. Marissa Harrison, an evolutionary psychologist and author, speaks to us about her research on female serial killers and how she was impacted by victims' stories.