In 1999 and 2000, women began disappearing from Detroit's thriving areas of prostitution. No one suspected that John Eric Armstrong, a seemingly normal father was actually a killer.
From 1975 and 1980, Billy Mansfield Jr murdered at least five people, but investigators suspect the extent of his serial killing is still to be revealed.
After a worker found the body of Jarrae Estepp at a California recycling center, detectives closed in on her murderer: Steven Dean Gordon, and discovered that he had killed before.