Investigation Discovery

TWISTED takes an in-depth look at the world's most prolific serial killers through first-hand accounts and testaments of those closest to them, and attempts to answer the question: Was it nature or nurture?

Hardcover Mysteries is an American true crime television series that airs on the Investigation Discovery network. Debuting on October 11, 2010, Hardcover Mysteries is produced in conjunction with Digital Ranch Productions, Inc.