If you haven't seen this seminal movie by Oliver Stone, it's still as fresh today as the first time I watched it. Kevin Costner's role as Jim Garrison is flawless and spell binding. I recommend you watch it even though we now know the Zapruder film was doctored and that the mob/mafia connections to JFK's murder were a whole lot less than the CIA.
However the broad thrust of the film is accurate. It is still important because the people who organised the President's shooting that day are still in charge.
Dick Cheney is the Allen Dulles of his day. There's no difference.