Richard Beasley was a conman and serial killer who posed as a preacher and in 2011, posted advertisements on Craigslist to entice men to work with him on his farm.

On June 12, 2016, Omar Mateen walked into Pulse nightclub in Orlando, Florida and massacred 49 people -- while wounding an additional 53 -- in the deadliest attack in American history.

In the course of one year, 1984-1985, Richard Ramirez conducted a reign of terror over Los Angeles -- killing 13 innocent people. His highly publicized home invasion crime spree led to the media dubbing him the "Night Stalker."

Drew Peterson's eldest son recounts his experience raising his half siblings in light of his father's arrest, as well as his personal journey from denial to acceptance of the fact that his parent is a murderer.