You know what happened. I think.
Anyway, I just saw the most amazing reproduction of the Zapruder film. It was recreated using still-photos of the original frames, and then digitally sequenced to make it a motion picture again. The dust and stuff is kept to a minimum. Also, they took the photos of the whole frame, not just between the sprocket holes. So we can see stuff that was never before seen.
Then they showed it in slow motion and close-up. Let me just say, you do not want to see a guy shot in the head from the other side of the shot. His head, like, exploded open and in a still-frame, you could see bits of brain and skull and flesh flying off. It was like his head was a tomato. An overly ripe tomato, and then someone thumped it.
He was obviously shot from in front, and not from behind.