Now that the Wizard has done all this photo analysis, I am left wondering whether the real Jack Ruby ever attended the Midnight Press Conference. He definitely went to the DPD late Friday night: TO DELIVER SANDWICHES TO THE DETECTIVES. The very idea of that tells you that he was NOT obsessed with Oswald. If anything, he was obsessed with the Dallas Police.
I checked Ken Rahm's timeline of Ruby's activities that weekend, and first I came to this:
11:15 P.M. Ruby claimed this was the first time that he had been to the station that day.
"The first time," a tacit admission that that was not him at the DPD at 2:00. And note that he made that denial during a polygraph examination: one which he passed, although the results were dismissed due to his mental illness. It was only done to humor him, which is strange in itself, because how many murder defendants have things done to humor them?
Oswald did admit going to the DPD late, and he placed the time of his arrival at 11:15. His purpose concerned the delivery of the sandwiches to the detectives. He, apparently, had no thought in his mind of seeing Oswald when he went there.
But, after that, there were many who reported seeing Ruby at the MPC. You can view them here under November 22 and early November 23, since it went past midnight.
Still, I have my doubts that that was him, and that's because we know for sure that some of the images were not him. And the only image that I am strongly confident was him is one that looks like a still photo placed into the film. (It was the Wizard who first suggested it.) You can watch it here in this gif, and as I watch it, I don't see the slightest movement in Ruby. None of them move very much, but you can see the cameramen fidget. But, even though he is in an awkward position, Ruby doesn't move at all; he doesn't flinch. The image is very suspicious.
The man on the right was the real Jack Ruby, but notice how much darker his suit was than the man on the left. Notice how much longer is head was. They are surely different men. The man on the left was balder than Ruby, and he had a hook nose which Ruby did not have.