Adding a crooked-cops twist to the outnumbered-and-under-siege plot that John Carpenter lifted from "Rio Bravo" for his "original" 1976 B-movie shoot-'em-up, the new "Assault on Precinct 13" is a reasonably entertaining update of a reliable action-drama formula.

The flick gets off to a powerhouse start with a flashback to undercover cop Ethan Hawke posing as a freaked-out addict (and giving a great performance) during a drug bust gone wrong. Six months later he's pushing paper at the Detroit Police Department's most run-down outpost in an industrial outskirt of town during a New Year's Eve blizzard.

It's supposed to be the last day this precinct is open -- the phones have been shut down and the joint has been largely cleared of officers, weapons and equipment. But the road-closing storm brings Hawke and his two remaining stock-character staffers (retiring beat cop Brian Dennehy and sexy secretary Drea de Matteo) some unexpected visitors: A department shrink (Maria Bello), trapped there after her required session with reluctant patient Hawke (he's guilt-ridden over deaths in the drug bust), and a small busload of prisoners in transit.

Chief among them is a cop-killing kingpin (Laurence Fishburne) whose arrest makes him a turncoat threat to a ring of corrupt detectives recently dropped from his payroll. Now they want him dead, and his overnight lock-up at isolated, snowed-in, nearly empty Precinct 13 is their best chance to see to his demise.

The story arc is obvious: Good cops and bad criminals must join forces and think cunningly to fight off the far better equipped enemy. Bullets fly, trust issues arise, bonds are formed and broken, confidence rises and falls, minor characters die in blazes of glory or stupid escape attempts, and director Jean-Francois Richet (making his Hollywood debut) keeps the action tight and lets his actors find a little nuance in their roles.

But in this remake, written by James DeMonaco ("The Negotiator"), many plot points are too obvious (like who among the precinct's defenders will become a traitor) and many more are questionable. How are the rogue cops blocking cell phone signals? Why are their snipers so bad at their jobs, and so bad at genuinely surrounding the precinct? What industrial part of Detroit butts up against a thick forest, convenient for a dramatic hide-and-seek finale?

The film's talented cast -- which includes Gabriel Byrne as the somewhat conflicted leader of the crooked assailants, and John Leguizamo and rapper Ja Rule as other transport prisoners -- is capable of holding one's interest through the weaker points of "Assault on Precinct 13." But it's a Saturday matinee at best.