Dean (John Candy) Andrews' sweaty face during his talk with Garrison is real. Candy was petrified at the idea of appearing in a dramatic film with professional actors like Gary Oldman and Donald Sutherland. He sweated profusely throughout all his scenes.
Those are real tears choking up Kevin Costner as he makes his closing summation as Jim Garrison. The weight of what he was saying meant the actor became emotional although the speech was not scripted that way.
Dr. Marion Jenkins, the anesthesiologist, plays himself in the film. He was genuinely surprised at the level of detail and research that had gone into preparation for that key scene. Even the tiles for the set of Trauma Room One were exactly the same shade of green he remembered (even though the scene itself is black and white in the finished film).
In preparation for her portrayal of Marina Oswald, Beata Poźniak studied the 26 volumes of the Warren Commission Report, read every single "Time" and "Newsweek" magazine article about her character, and then actually lived with the real Marina for a while.
"X", Donald Sutherland's character, is based on L. Fletcher Prouty, Chief of Special Operations for the Joint Chiefs of Staff (and, thus, principal liaison officer between the Pentagon and the CIA) during the JFK presidency. He was a technical advisor for the film.
For the recreation of the assassination at Dealey Plaza, the producers had to pay the Dallas City Council a large amount of money to hire police to reroute traffic and close down streets for three weeks. Stone only had 10 days to shoot the entire sequence. Director of photography Robert Richardson employed two 35mm cameras, five 16mm cameras and 14 different film stocks for the sequence.
Even before "JFK" had finished filming, the Washington Post national security correspondent George Lardner showed up on set and wrote a scathing article attacking the movie. Lardner based this on the first draft screenplay he had read. Other leading newspapers followed suit upon the film's release, many taking particular umbrage with the liberties with the facts that Oliver Stone had taken.
Veteran movie critic for The Washingtonian Pat Dowell had her 34 word capsule review for the January issue rejected by editor John Limpert, a known opponent to the film. Limpert didn't want a positive review for a film that he regarded as treacherous. Dowell resigned in protest.
During the party scene flashback, Clay chastises David Ferrie, "Always one hare-brained scheme or another." He is right, too. The real David Ferrie was famous for doing stupid things. He once tried to turn a water tank into a submarine, unsuccessfully.
Getting permission to film in the Texas School Book Depository proved to be very difficult. The Depository demanded $50,000 to put someone in the window where Lee Harvey Oswald had stood. They were only allowed to film at certain times of the day, with only five people allowed on the floor at any one time. Co-producer Clayton Townsend said that the hardest part of the whole process was getting permission to transform the building back to the way it looked in 1963. That took five months of negotiation. Scenes of interior action on the sixth floor were actually filmed on the fifth floor, as the sixth floor is a museum exhibit. But all point of view shots of the motorcade were filmed from the actual sixth floor window, as well as all shots of the shooter behind the window as seen from the outside.
When shooting footage of the grassy knoll gunman Oliver Stone could not find a gun which made enough smoke to be visible. Since modern guns release almost no smoke from their barrels a smoke machine was made to get the effect which they wanted.
Oliver Stone was given a copy of Jim Garrison's book, "On the Trail of the Assassins", by a friend to read on the plane to the Philippines during the filming of "Platoon". After reading the book, Stone knew he'd found a new film project.
James Woods eagerly lobbied for the role of Garrison. However he and Oliver Stone had vast creative differences, Woods wanting the film to be more of a biography of Jim Garrison with much more emphasis on his personal life, while Stone wanted it to be primarily about the case.
Perry R. Russo, who was a key witness to conversations taking place between David Ferrie, Clay Shaw (aka Clay Bertrand), and Lee Harvey Oswald, plays a man in the bar at the beginning of the film, where Garrison and Lou are watching the TV coverage on the shooting. Mr. Russo yells about how they should give the shooter a medal for shooting Kennedy.
Garrison's final lines in the film - "If it takes me 30 years to nail every one of the assassins, then I will continue this investigation for 30 years. I owe that not only to Jack Kennedy but to my country" - are lifted directly from the last word of his 1967 'Playboy' magazine interview.
When Joe Pesci is ranting about the assassination, saying that no one will ever solve the JFK murder, he utters the famous line, "It's a mystery wrapped in a riddle inside an enigma...." He was paraphrasing Winston Churchill's quotation, made in a radio broadcast in October 1939: "I cannot forecast to you the action of Russia. It is a riddle, wrapped in a mystery, inside an enigma; but perhaps there is a key. That key is Russian national interest."
Stone hired Jane Rusconi, a recent Yale graduate, to head up a team of researchers and assemble as much information about the assassination as possible while he completed his directing duties on Born on the Fourth of July (1989). While Stone read two dozen books about the assassination, Rusconi read well over 200 books on the subject.
Shortly after the film's release, film critic Roger Ebert received a tongue-lashing from Walter Cronkite, berating him for praising "JFK". Cronkite was adamant that there wasn't a shred of truth to the film.
Computer mock-ups of the assassination, particularly one by Dale K. Myers have since strenuously argued against the Magic Bullet Theory as presented in this film by pointing out that the Presidential Limo actually had a step in its manufacture, moving the passenger seats inwards. This had been overlooked in Garrison's diagram. However, Myers' simulation is not without criticism of its own in regard to accuracy.
The film alludes to the so called "umbrella man" as being part of the conspiracy, possibly as some type of signal for the shooters since he is standing very near to the limousine as Kennedy is shot. The implication is he and/or his motives were never identified. However, in the late 1970's, around ten years after Clay Shaw's trial, he was identified as Louie Steven Witt, and actually testified before the House Select Committee on Assassinations. According to filmmaker Errol Morris, and published with the New York Times, this mystery man opened his umbrella as Kennedy drove by, not for any sinister reasons, but to protest against Kennedy's father, Joseph P. Kennedy, who was an ambassador to Britain, and is a reference to former British Prime Mister Neville Chamberlain's umbrella. Morris's short film describing this is entitled "The Umbrella Man."
Every detail concerning the set for the Oval Office was meticulously reconstructed based on archival footage of the White House during President John F. Kennedy's term. The set cost about $70,000 to complete, yet it only appears in about eight seconds of film and is in black and white.
"The bigger the lie, the more people will believe it" was a Nazi quote, but this concise version did not belong to Adolf Hitler; it was spoken by Joseph Goebbels. Hitler had written "...in the big lie there is always a certain force of credibility...in the primitive simplicity of their (the broad masses') minds they more readily fall victims to the big lie than the small lie..." in "Mein Kampf" (Vol.I, ch.10, p.252; (c)1925).
The characters "Janet and Bill Williams" are based on Michael and Ruth Paine who, like in the movie, take in Marina Oswald into their home. Ruth Paine alerted Lee to the job at the Texas School Book Depository.
When Ferrie is raving about the necessity of killing Kennedy in order to free Cuba, he is unaware of a bitter irony. Part of the deal worked out by JFK to get the missiles removed from Cuba was a pledge by the USA not to invade the island nation. This was revealed only after the USSR/Soviet Union collapsed and the Kremlin archives were opened to the public. This is why, even after JFK was killed, Cuba remained a communist nation after the Cold War ended. The U.S. trade embargo against Cuba, which was enacted February 7, 1962, is still in effect. As of 2013, there are five Communist nations still in existence - Cuba, People's Republic of China, Socialist Republic of Vietnam, Democratic People's Republic of Korea (North Korea), and the Lao People's Democratic Republic (Laos).
The film generated intense controversy upon its release with many accusing Oliver Stone of making up many of the facts. In fact, Stone published an annotated version of his screenplay, in which he justifies and attributes every claim made in the film. Stone later addressed the controversy in his TV movie Wild Palms (1993) in which he has a cameo. That film takes place in the 21st Century and has Stone appearing on a talk show discussing how all his conspiracy theories surrounding "JFK" had been proven true.
James Belushi makes a cameo in Director's Cut as an accomplice of JFK's murder. He appears in Elm Street (where the president was killed) as archive footage when Jim Garrison explains step by step the JFK's murder in the trial.
Oliver Stone made a handshake deal with Warner Brothers on the proviso that the studio would retain all rights to the film if they stomped up $20 million for the budget. Stone did this deal because he didn't want the screenplay to do the rounds of all the studios, thereby lessening the chances of potential leaks.
During one scene of an NSC meeting, a general accuses Kennedy of having "...his hand on the chicken switch again." A Chicken Switch is an emergency cut-off button installed in Air Force flight simulators. If the testing candidate feels his life is in danger, he can "chicken out" by shutting down the machine. By using this vernacular, the general identifies himself as both a pilot and an Air Force general.
Several times when talking about Washington D.C. Mr. X (Donald Sutherland) says, "inside The Loop". He is referring to the convergence of several freeways around the nation's capital. The nickname is common to natives and those who work in Washington D.C.
The television show Seinfeld (1989) would later parody the "magic bullet" theory featured in "JFK" in an episode where Kramer and Newman believe that they had been spat at by NY Met Keith Hernandez. Jerry diagrams the course of the "magic loogie" and Keith later reveals that there was a second spitter, Roger McDowell. Wayne Knight, who plays Newman, is also in "JFK" as a member of Garrison's team. He would be one of the two men to model the shooting in court to prove the implausibility of the "magic bullet", not unlike how Jerry disproves Newman and Kramer's theory.
During the conversation between Jim Garrison and X, there is a close-up of a desktop nameplate which is partially obscured. It reads "M/Gen. E.G... nsd... e", and is a reference to Edward G. Lansdale of the United States Air Force. Lansdale is the subject of the book "JFK and Vietnam" by John M. Newman, one of the film's technical advisors.
During the conversation between Jim Garrison and X appears a flashback in black and white which a headmen group of some organizations (CIA, NSA, Pentagon... ) plot to control Kennedy, and one of them ask Max Taylor follows McNamara. Max Taylor is really Maxwell D. Taylor, general of USA Army in this time, and McNamara is really Robert McNamara, United States Secretary of Defense when Kennedy was President and one of the Kennedy's advisers.
The real Jean Hill filmed a cameo in which she played the stenographer during her own questioning. The shot was composed so that her face and the face of Ellen McElduff playing her would ironically be seen on split sides of the screen. But it didn't make the final cut. Her cameo can be seen as an outtake on the 2-disc special edition DVD.
The movie mentions a conflict of interest connection between Vice President Johnson and a military contractor called Brown and Root and its financial motivations in preventing Kennedy's ending the Vietnam war as a motive for Kennedy's assassination. The same corporation, now known as Kellog Brown and Root (KBR) a subsidiary of Halliburton, was a military contractor connected with Vice President Cheney.
Jeff Bridges and Nick Nolte were both considered for the role of Jim Garrison. Bridges was turned down because he was not a major box-office draw, while Nolte was considered to be too old. He later worked with Stone in U Turn (1997).
When discussing the Oswald impersonators, Laurie Metcalf's character tells them about one of the impostors going to buy a car. The salesman remembers him being 5"7 but the real Oswald was 5"11. In reality, Frank Whaley, who plays the impostor, is 5"7 1/2, while Gary Oldman, who plays Oswald, is 5"9.
Oliver Stone can be seen very briefly in the assassination re-enactment. Look very close for him as the Secret Service agent who runs towards the back of the limo after the fatal headshot.
The trivia item below may give away important plot points.
Garrison's meeting with Mr. X was originally scripted and shot as two different meetings, the second one occurring after Garrison has lost the case, and it would have been the last scene in the film. During post-production, the two meetings were weaved into one. On the Special Edition DVD the complete alternate scene is available.