William Stanley Milligan, aka Billy Milligan, was an American citizen who committed several felonies and was arrested for 3 rapes on the Ohio State University campus. He was the first person acquitted of a major crime because of the multiple personality disorder.

Billy's lawyers claimed that the crimes were committed by two of his alternate personalities. Billy was the first criminal with multiple personality disorder to raise such a defense.

Billy Milligan had 24 personalities inside his head. Only 11 of them were "the good" guys. Others were defined as "The Undesirables".

Have you ever heard about Billy? What do you think about his case? Was he really mentally ill? You are welcome to share your opinion in the comments below!