"RUBY," coming out hot on the heels of Oliver Stone's "JFK," is, of course, the story of Jack Ruby (played by Danny Aiello), the man who shot Lee Harvey Oswald. But this movie isn't really about the Kennedy assassination. Nor is it a satisfactory explanation of the main character's most famous moment . . . though it does foster an argument about why he did what he did.

"Ruby" is actually little more than just another gangster picture with an unusual hook.

The film spends 90 percent of its screen time showing Ruby as a low-life nightclub owner in Dallas who dallies with mobsters, corrupt cops, FBI agents and, unwittingly, with the CIA. He aspires to a prestigious position with organized crime, though he realizes that will never happen.

Once in awhile, the Ruby depicted in this film turns the tables on his challengers, but most of the time he's just another pawn in a bigger game.

A subplot, one that takes up too much screen time, has him in a platonic mentor-style friendship with Candy Cane (Sherilyn Fenn), a young stripper he takes in and puts on the road to success.

But an explanation prior to the end credits tells us Cane is a completely fictitious character, which may well cause the audience to wonder just how much of the rest of the movie is fictitious.

And in the end, Ruby's action against Oswald, his trial and the end of his life is far too rapidly dispensed with.

A better film should have given us less of Ruby's life before the killing of Oswald and more of the trial and his subsequent prison term.

The one thing "Ruby" has going for it that manages to keep things afloat is an excellent, often surprisingly subtle performance from Aiello in the title role. He is far and away the only reason to see this film.

"Ruby" is rated R for violence, profanity, nudity and vulgarity.