Oh, good grief. We absolutely know who shot Kennedy. People who live their lives based on faith alone, of course, refuse to believe it, belief being the operating word. If you choose to believe in a supernatural deity despite zero credible evidence, or you refuse to believe the truth about something despite irrefutable evidence, that is your choice. If you want to justify your belief by saying it is beyond your capacity to understand, that is your choice. There are plenty of theists-even writing articles here at Medium-who insist that they have the evidence. Yes, human knowledge is fallible, hence scientific methods require constant analysis and testing and re-testing until errors are eliminated beyond a reasonable doubt. But human knowledge is not finite, it is growing constantly and has no end. I place priority on science. You can live your live by the instructions of your religious authorities.