LBJ was in on it. He was a great actor..
I still say the kill shot came from the sewer grate. If you look on Google Maps it is right there, and the culvert goes away from the scene, conveniently...
Cui bono or who benefitted? LBJ. First, Life Magazine was going to run an expose the following Monday on his corruption and that of his chief Senate aide, one Bobby Baker. Second, JFK had told his secretary, Evelyn Lincoln, that he intended to dump LBJ as VP in 1964 when he was to return from Texas. Third, Jackie told the biographer William Manchester that LBJ was behind it. Fourth, Jackie overheard an argument between JFK and LBJ at his Fort Worth hotel room the night before in which LBJ was adamant that Ralph Yarborough, whom he detested, and not his protege John Connally ride with the President, an argument that LBJ lost. Fifth, LBJ lied about Secret Service agent Rufus Youngblood jumping on him while the bullets flew - the back seat could not accommodate this and Senator Yarborough, who rode with LBJ, said it never happened.