In the world of conspiracy theories, this one ranks as the current ""official"" view of the plot to kill JFK; and if you were paying attention during the proceedings of the House Select Committee on Assassinations, you've heard about it before. Blakey was Chief Counsel and Staff Director, taking a break from teaching law, while Billings is a journalist (Life) who helped write the report. The conclusions of the investigation come down to a theory for which there is little conclusive evidence, but much of the circumstantial sort. Blakey is certain that there was a second gunman in Dallas behind the ""grassy knoll"" who fired one shot that missed altogether, while Oswald fired three shots and is indeed the killer. The second gunman--who, Blakey thinks, should have been discovered by the Warren Commission--signifies that there was a conspiracy. As to who was involved, that remains conjecture. The best guess is that organized crime and Cuban exiles with CIA connections were involved. Oswald ostensibly was recruited on the pretext that he was aiding pro-Castro forces, while in actuality it was the reverse; Jack Ruby, according to this scenario, was a classic hit man. What the Committee knew was that the Mafia-types wanted Kennedy dead because of Robert Kennedy's anti-crime investigations; and that the Cuban exiles were miffed over the Bay of Pigs invasion. They were also aware of what gangland-style assassinations look like, and can establish personal connections between enough people to make the whole theory plausible without naming any names; they're sure, moreover, that the names will never be known--so this, presumably, is the final official word. As such, it leans more heavily on Mafia involvement than on the Cuban connection (which seems, by comparison, to have been under-investigated). Since most of the crime figures are dead, the Cuban connection may indeed leave some stones still to be turned by others.