This was many years ago, why'd he do it? What do you think? I've read the Wikipedia article, but I couldn't find a motive.
Lee Harvey Oswald did have a motive. Every murderer does. Unfortunately, he was killed by Jack Ruby before people could get anything out of him. A lot of people think it was just a huge conspiracy involving the mafia, because JFK's brother Robert Kennedy was trying to cut down on organized crime.
The guy was just stressed I'm not sure and we'll never know why he killed Kennedy cuz he's already dead so oh well....
I believe that Oswald wasn't alone, given JFK's exit wound. Oliver Stone painted Oswald almost as a saint who was completely framed. I wouldn't go that far, I think Oswald did shoot and did mean to kill. However, I do think there was a second gunman on that grassy knoll.