Karen Kuzma--sister of John Wayne Gacy--comes out of the shadows to reveal intimate details of one of the world's most notorious serial killers.

Cindy Brown reveals how her childhood sweetheart and husband, Bobby Joe Long, evolves into a fiend who rapes more than 50 women, ultimately killing 10. Their son Chris, talks on camera for the first time, revealing his struggle as a serial killer's child.

Mildred Muhammad--ex-wife of infamous "DC Sniper" John Allen Muhammad--reveals how the man she loves disintegrated into a monster who threatens to kill her.

Randy Hausner--brother of serial shooter Dale Hausner--shares the inside story of a man who terrorized the city of Phoenix in a year and a half-long killing spree. He reveals his brother's never before seen journal disclosing a chilling view on the development of a killer.

Amber and Michelle Yates--daughters of serial killer Richard Yates--tell the inside story of being raised by a man who terrorized the city of Spokane, Washington. The episode reveals devastating details and chilling home videos of a strict father who disciplines his children by day, and hunts innocent women by night.

Melissa Moore--daughter of Keith Hunter Jesperson, infamously known as the "Happy Face Killer" tells her own personal story as the daughter of a serial killer. The episode reveals shocking behind-the-scenes accounts of what it was like growing up with a father who, she later learned, was committing horrific murders.