When the story concentrates on Garrison and his team and the information they uncover, it often settles nicely into a thriller/whodunit motif with an energy all its own. But it's never long before Stone, hardly a subtle filmmaker to begin with, interrupts with some sensationalizing — the body of the president shown in gory detail while an autopsy is performed, flamboyant images of the New Orleans gay subculture, the home-movie footage of the shooting of the president repeated incessantly, etc. Those elements tend to undermine Stone's attempt to be taken seriously. As do scenes where characters give testimony while black-and-white flashbacks show the "truth."

And toward the end, when Garrison confronts an informant who was once a high-ranking military man and later goes public by prosecuting Clay Shaw as a conspirator, there are two impossibly long set-pieces — a park bench explanation and Costner's passionate closing argument to the jury — which seem to go on forever.

Of the many fine performances in Stone's large cast, standouts include Gary Oldman as Lee Harvey Oswald, Tommy Lee Jones as Shaw and Joe Pesci as Shaw's cohort David Ferrie. And the film itself is slick and sporadically entertaining.

Stone avoids facts that don't suit his purposes and manipulates several separate theories so that they all become a part of Garrison's investigation. He even links the later assassinations of Martin Luther King and Bobby Kennedy to the president's death.

Not that it should be surprising, given Stone's distortion of truth in favor of dramatic impact in "Born on the Fourth of July" and his strident tone in "Platoon" and "Wall Street."

But it might be confusing to young people who walk in ill-informed and accept this cinematic dissertation as fact-born.

As scenery-chewing entertainment, "JFK" would appear to be an interesting failure, but certainly conspiracy theorists will want to take a look. After all, Stone probably made it for them anyway. Or did he really expect to convert a segment of the more conservative audience?

"JFK" is rated R for considerable violence, gore and profanity, along with some nudity in a strip club, vulgarity, drug abuse, homosexuality and implied sex.