Read page 4 of the deposition of Dr Paul Peters who was one of the doctors in the ER in the Warren Commission. He clearly states there was a large occipital (back of the head) wound which was judged to be mortal. Could only come from a frontal entry/rear exit.
Thanks, you dive deeper than I do. I surmised that, the big clue was the path of brain matter, then the stupid watermelon test. Any guy from 12 to 120 has thought of using TV’s, beer cans, road signs, and watermelons for targets. First shot was highly likely to have been from the front, through the throat, kill shot also, only into the skull.