On the other hand, the shot from the wall behind the "grassy knoll" is even shorter, only about a 40 yard shot. That looks like the shot that a clear-thinking professional hit man would have chosen. So who knows, maybe the final shot was fired by a professional with a silencer from the grassy knoll. That's still possible, but there's no evidence to support that theory. It's also possible that other people helped Oswald, although he didn't really need any help.
A lot of people have commented that Dealy Plaza and the grassy knoll area is quite small and would have been difficult for an assassin, though not impossible. I'm convinced Oswald had help because of the direction Kennedy's head took on the fatal hit, which was to the back and left. We've heard a lot of the "jet effect" theory that a hit from the back could have caused his head to go that way but I have a hard time buying it, most likely it did because he was struck in the front right temple.
There are other discrepancies between the official Warren Report and direct witness testimony as well that point to more than one gunman. Mrs. Connally for example, even though she believes Oswald acted alone swears to this day the single bullet theory was inaccurate because of the way she heard the bullet sounds. First Kennedy was struck, then a few seconds later a separate shot hit her husband. That would mean there were at least four shots and another gunman. And there were others who swore they heard shots from the knoll.
As far as Oswald: the police got the man right man, he was up there and was firing at Kennedy. Too many conspiracy theorists want to pretend he wasn't or that he was setup but the evidence is overwhelming he was involved.
Throwing the rifle at JFK would have been about as effective as using it to shoot at him. It was a piece of junk and hadn't been fired in months if ever. There is no record or even hint that Ozzie even bought ammo for it nor any excess found.