Isn't it amazing that a piece of skull bone that big went flying out of Kennedy's head? It tells you certain things. For instance, it tells you that he wasn't shot with a standard FMJ bullet because that would have passed through his head intact. The bullet used exploded inside Kennedy's head, which created an expansile force which blew out that piece of bone. They needed that bullet to disintegrate because, from that angle, if it had passed through JFK's head intact, it could have hit Jackie. And remember: they needed Jackie to be standing next to LBJ at the swearing-in ceremony.
Now, I am NOT suggesting that she was in any way part of it. She was manipulated, through and through. Look at that picture! LBJ's wife Lady Bird is some distance away. The "couple" there is LBJ and Jackie. And she's there because she represents the embodiment of JFK granting his approval and blessing to the passing of the torch to LBJ. The legitimacy of the transfer of power comes from one thing and one thing only: Jackie Kennedy being there. So, they had to make darn sure that they didn't shoot her. If she were lying in a casket, dead, maimed, and bloodied like JFK, it would not have looked so good.
The Harper fragment is proof that they used a frangible missile to shoot Kennedy from the Grassy Knoll, and it is proof that his head was blown out in back.