Who was Jack Ruby? Whatever he was he was not patriotic. He did what he had to do when he killed Lee Harvey Oswald, and he knew why.
When an oligarch orders a hit, he's certain it will never come back to him.
Who was Lee Harvey Oswald? Oswald was a nut, just the kind of person to get for this type of mission. He was solicited by Jack Ruby; when Ruby came up to him, he expressed recognition of Ruby. He had a look of total astonishment on his face after he was shot.
Why is discussion of this subject total taboo, that's the question everyone should ask.