Lee Harvey Oswald

Lee Harvey Oswald was, according to five government investigations, the sniper who assassinated.

History
When Homer and Marge tried to solve Who Really Killed J.F.K., Homer told Marge he had figured it out: Lee Harvey Oswald wanted to steal the Jack Ruby. Marge then informed him that Jack Ruby was a man, not a jewel. Homer became mad at this statement, as they were back to square one.