I still can't see how the head shot came from anywhere else but in front of JFK, though, given the Zapruder film. Did the back brace cause Kennedy's body to slam backward? Doesn't seem likely to me.
I have actually been to Dealey Plaza in Dallas, and scoped out all the famous sites. Ghoulish, but at least I saw for myself, as much as possible.
That's about as far as I take the matter. The rest just becomes conjecture upon conjecture.

There are at least two versions of the Zabrudder film out there. One shows Connolly turning around just after Kennedy is hit in the neck, prior to the head shot, then turning back to collapse in his wife’s lap; and is touted as a two shot version. The second version is the three shot version, which has a longer segment between Connoly’s turn and the collapse into his wife’s lap. Mrs. Connolly backs the second longer versiona nd the three shot scenario and says quite convincingly ‘Those pushing the Warren fantasy weren’t there to hear the htree shots.’ She’s right, since evn a SS guy at the rear of the limo claims he heard three distinct shots, with two very close together after the first with a pause before the following two, one of which was the Kennedy headshot. Connolly was not hit until after the Kennedy neckshot and just after or just before the head shot. Three shots, Senator ‘Scottish Law’ notwithstanding..
I still can’t see how the head shot came from anywhere else but in front of JFK
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The video in post 134 will answer your question, simple physics proves that the shot came from BEHIND.