How can you tell by looking at my photo that Specter is demonstrating the right to left trajectory? I can't. I suspect that John Mytton would be able to tell.
Because I can see from that photo the rod is being held above the entry point on the jacket and the other end of the rod is on the entry point on the back of the agent taking JBC's place. That puts the rod above the path of the bullet.
Can you link to some photos in which the jacket can be seen to not be lifted up at all?
By lifted, do you mean bunched up at the top? The picture I posted earlier shows that quite nicely? I have since learned in another thread that is one of Phil Willis' slide photos.
The Croft photo was taken on Elm street, at about the same time as Zapruder frame 160; 3.44 seconds before the single bullet shot.
I'm using the bunch jacket argument for two reasons. One, the jacket was bunched up. Two, the holes in the shirt and jacket are 5.5 inches below the tops of collars and the wound itself is about 2.5 inches below the tops of the collars. I don't believe that the curvature of JFK's back was anywhere near enough to make up for that 3 inches
I hadn't looked closely at the background when you first posted the Croft photo but on further inspection, it does appear the west end of the TSBD in the background. Can you sync that photo with a Zapruder frame. I started a thread to get someone to assist me with the Willis photo and there's a good argument it syncs up with Z145. It appears we have two photos taken seconds apart, one showing a bunched jacket and one in which it was not bunched. The difference seems to be the position of JFK's right arm. When he had his hand up by his forehead, the jacket is not bunched. The Croft photo seems to be with his arm down. Just before the bullet struck, his arm had been up waving to the crowd but he was lowering it when he disappeared behind the sign. So with his arm part way down when JFK was struck, was the jacket bunched or not? Who knows? I think the fact the top of the jacket was not vertical but tilted forward had more to do with reducing the vertical separation between the top of the jacket and the entry point. The entry point would not have been 5 1/2 inches below the top of the jacket whether the jacket was bunched or not.