As a chiropractor, I am very tuned-in to postural habits, and we are seeing the exact same postural arrangement in the collage of Young Bookhout and the Garage Shooter. But, Jack Ruby was a different story. His postural habit- the way he held his head- was very different. He held his chin higher, which means he cocked his head back slightly, while he also bent his head slightly to the right and rotated it slightly to the left. It was a very complex hold and not a relaxed one. This was a very deep-seated postural habit that he did subconsciously. It is very different from what we see in the other two images which are of James Bookhout. I'll say this for Bookhout: he had a very relaxed posture- especially compared to Jack Ruby.