Oswald was a patsy
They set him up to take the fall.
He may have thought there was a plan to STOP the shooting and he was there to help- I think he was a plant inside the commie operations to spy on them, but not a very bright or useful one
So they had him be there for the shooting, and he sat it out, not knowing they were setting him up to take the fall for it
Sorry, but these conspiracy theories are total B.S.
The shooter in the grassy knoll turned out to be B.S.
The three rail yard workers did NOT see a shooter from their position on the triple overpass.
The best refutation of the magic bullet theory:
http://www.youtube.com/watch?v=DSBXW1-VGmM