I don't think the most serious allegations of Richard Cain's connections to the assassination place him in Dealey Plaza, but rather, some other incidents that he was allegedly involved in, like the discovery of the rifle order at Kline's, and whether Cain knew of Giancana's role in the CIA plots to kill Castro and in getting the West Virginia Sherrifs to support JFK's primary election.
Maybe Michael addresses these issues in his book?
BK
Bill,
In my book I talk extensively about the CIA-Mafia plots against Castro and Richard's role in those plots.
His supposed discovery of the purchase at Kline's was reported in the Chicago press by a gossip columnist, but may have been based on a self-serving boast from Richard, I haven't found any direct evidence to support the claim. I'm not denying it, just can't prove it.
Nor did I find any evidence regarding the West Virginia Sheriffs. It isn't likely, though, that he played a role there. I have a pretty good idea of where he was throughout 1960 and I don't see much in his activities that would support that. Again, it could have happened, I just haven't seen any evidence.
Hope that's helpful,
Michael