I should have made clearer why I brought up the grassy knoll gunman point. One of the major critiques of the Garrison trial was that he was just a paranoid DA who was looking to indict every Tom, Dick and Harry with conspiracy to murder the president. Hence, I just wanted to make clear I think this is a bogus claim, although you yourself weren’t arguing this.
To answer your final question, yes I do believe Clay Shaw was involved in a conspiracy to kill JFK, due to the evidence today as well as what was available at the Shaw trial. His consistent lying throughout the build up in the trial for me doesn’t help prove his innocence. As a Brit I’m not fully aware of how your conspiracy laws work, so Dr Wager’s comment was especially useful. I certainly don’t think he’s as complicit as members of the CIA, FBI, Secret Service etc., but with these type of cases you have to start small and peel back the layers. It reminds of The Untouchables, where they start off small, then get the bookmaker, before finally getting Capone.
As has been pointed out Garrison had good reason to go after Shaw, based on the certain initial instances. Had the Dean Andrews debacle not happened, as well as David Ferrie’s weird story about his trip to Texas, I doubt Garrison would have even attempted to start investigating. As DA, he was well aware of Ferrie and Bannisters right wing leanings, which should make anyone question why so many people saw them hanging around ‘communist’ LHO. Even though he wasn’t privy to what we have available now, I believe he was right to charge Clay Shaw with conspiracy.