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Yet the Willis girl stopping approx Z195 and the Betzner 186 photo and Willis Z205 photo are valid reasons to consider that the 1st loud shot heard was at Z195-200 approx.
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Certainly Rosemary Willis coming to a stop around z195 is not evidence for a shot at z195-200. Because what is relevant is not when she came to a stop but when she started to slow down. Humans, girls, indeed objects in general cannot stop on a dime, unless they run into a brick wall. They have to decelerate, which takes some time. We have to take into account basic physics.
I have studied frames of the Zapruder film using the Costella images which anyone can find by googling 'zapruder frames'. I invite anyone to do that, to see how far she goes from z150-160, with z160-z170, with z170-z180, with z180-z190, with z190-z200. You can check her position relative to some stationary object like the standing man she disappears behind at z154. And draw a simple diagram of a large rectangle representing the man, and shorter rectangles showing Rosemary at z150, z160, z170, z180 and z190. It appears to me that she starts to slow down sometimes during the z160's and is almost stopped by z180. Between z150-z160 she travels about one and a half of her own width (from Mr. Zapruder's angle). But between z160-z170 she only travels about one width. She is clearly slowing down during the z160's.
Considering that it takes a human mind a little while to react to a loud noise and decide what to do, starting to slow down during the z160's is not at all evidence of a shot around z195-200 but is consistent with a shot at z152, which corresponds to a Zapruder camera jiggle around z157.