Loved ones grew concerned when Goldie Robinson allegedly eloped with a mystery multimillionaire and gave her home and possessions to a new family.

Peggy King had recently helped a girl handle an abusive partner. Was that why she vanished?

Dr. Judith Calder was previously attacked by a man who told her, "Someone at the university wants you dead."

Investigators looked into a theory that 74-year-old Skip Scandirito disappeared while kayaking with a mystery woman he met at a golf course. 

Billy Sproates' brother knew something was wrong when he didn't show up to a scheduled hunting session in the Delaware forest.

Tera Lewandowski was looking for a fresh start when moving in with a town council member who led a double life.

Was Bryan Ruff an overwhelmed father who walked away from his life? Or did something more sinister happen? The theories ran wild around the 1991 disappearance of a man who simply vanished from his graveyard shift. 

Between boyfriends and stepfathers, there was no shortage of suspects in the disappearance of Becky Stowe. 

A caped stranger nicknamed "The Count" lurked around L.A.'s Sunset Strip in search of his victims, including 18-year-old Lisa Ann Mather. 

Boyfriends and serial killers were just a couple of theories surrounding the 1987 disappearance of Vickie Eddington.