Epistemology is the study of the theory of knowledge, that is: What constitutes knowledge? What makes something a fact? What is the criterion for claiming that you know something. Not that you believe something; not that you accept something; not that you surmise something; but that you know it; that it is a bankable fact.
Now, let's apply Epistemological theory to the claim that Jack Ruby shot Oswald. On what basis is that claimed to be a fact?
First, there is the fact that many people believe he did. Millions.
Well, Epistemology doesn't give a shit about that. Epistemology pisses on that. That means nothing to Epistemology. Not little, but nothing. Nada.
Millions of people can be wrong. I'll say it again: millions of people can be wrong.
There is the fact that Jack Ruby admitted doing it. But, did you ever listen to him? Did you, or did you not, notice how baffled and incoherent he sounded? He sounded dopey and confused as he mumbled, stumbled, tumbled around talking about it. And, he said that he had no memory of doing it. He said he remembered going to the garage, and the next thing he remembers is being piled upon by police. That's it. Nothing in-between.
You can't just look at the abstraction of Ruby saying that he did it. You have to actually listen to him say it and assess his credibility in saying that he did it. And when I do the latter, I come away with a lot of misgivings. To me, Jack Ruby sounded very much like Sirhan Sirhan who said and still says that he has no memory of shooting Robert Kennedy.
So, does the totality of what Jack Ruby said in claiming to have shot Oswald, including what he said and the manner in which he said it, make it an epistemological certainty that he did it? Of course not. Not by a long shot. People make false statements all the time. Do I have to point that out? People often lie. People are often mistaken without lying. And in Jack Ruby's case, there is grave concern about the state of his mind, because he did not sound clear and lucid. He never sounded clear and lucid.
So, the Epistemology Judge says no when it comes to claiming knowledge from that. It doesn't begin to meet the threshold.
What's left? There is the photographic evidence, which should be what cinches it. But, in this case: THERE IS NO IMAGE OF THE SHOOTER THAT PROVIDES ENOUGH VISUAL DATA, ENOUGH VISUAL INFORMATION. TO IDENTIFY HIM AS JACK RUBY. We simply don't see enough of him. For instance, you can't claim from looking at this that the shooter is Jack Ruby.
You know how fingerprint matching works. They compare different "points" in the fingerprint to corresponding points in the unknown fingerprint, and it takes a certain number of point-matches to declare that it's the same person who made both prints. How many matches exactly? That's often debated, but the more the better. And, you can't put a known image of Ruby up next to that guy and make enough point-matches to state, categorically, that he was Jack Ruby. You can't because it is too possible for someone to look that much like Jack Ruby without being Jack Ruby.
Then, there is the mere fact that there is no image of the shooter's face. With as many cameras as there were in that garage, doesn't it seem like one of them would have captured his face?
And don't even bring up those bull shit images from Backes. I'm talking about the guy above.
And then there is the fact that Dallas Police made the unusual response of herding the shooter out of the area without stopping to cuff him first, and the very fact that the mob of men knew to do that is disturbing. We don't hear anyone shouting orders. So, how did they know that was the plan? Doesn't it seem likely that at least one of the cops would have taken out handcuffs and tried to cuff him?
So, there is no photographic proof that the shooter was Jack Ruby, and the behavior of the police in sprinting him out of there, in mob-like fashion, only makes it more troubling.
So, the bottom line is that, epistemologically speaking, there is no proof that that shooter was Jack Ruby.
Now, if you want to believe he was Jack Ruby, you can, and I can't stop you. But, don't try to claim that you KNOW that he was Jack Ruby, because you can't possibly know that, and I won't let you get away with it. I won't. I'll call you on it every time. And, I'm sure Plato and Socrates are siding with me on this.