Ten minutes into "Street Kings," the film bluntly shows us what to expect for the next 100.

Tom Ludlow (Keanu Reeves), fresh from a beating at the hands of two Korean hoods, bursts into their lair, shoots everyone in cold blood, and puts a gun in a corpse's hand for his "they fired first" alibi. Ludlow casually feeds the lie to his complicit fellow police and gets a hero's tribute in the press. The scene sets the tone for this grimly violent film and the murk of official corruption its characters swim through. Our screen surrogate, an amoral, remorseless killer, is the best vice cop in Los Angeles.

"Street Kings" gives us a scuzzy world where the distinction between perps and lawmen is dim at best. Co-scripted by brutalist crime writer James Ellroy, and directed by David Ayer, who wrote the depraved-cop drama "Training Day," the film wears its cynicism on its blood-soaked sleeve. Everyone in the large cast is presented as a possible bad guy, and almost everyone is one, to some degree.

Ludlow follows the grand tradition of loose-cannon policemen. He starts his day with a puke and cleanses his palate with a vodka mouthwash. Living on the edge since his wife died in another man's bed, he's the animal the force turns loose to hold back the animals.

Ludlow despises his do-gooder ex-partner, suspecting that he's about to rat him out for planting evidence. When the man ends up as a slippery floor hazard following a convenience store shootout, Ludlow is a prime suspect, caught between his manipulative mentor, LAPD vice Capt. Jack Wander (Forest Whitaker) and aggressive Internal Affairs Capt. James Biggs (Hugh Laurie). Demoted to paper-shuffling duty in the headquarters complaint desk, Ludlow spends his free hours digging into his old partner's death, uncovering a labyrinthine trail of wrongdoing that reaches the heart of the department. It's a good role for the poker- faced Reeves; his noncommittal expression keeps us guessing about his every move.

"Street Kings" wobbles increasingly as it runs along, beginning well, growing so-so and culminating in a preposterous here's-what-it-all-means confession by the main villain. Still, the film has technical polish and inventive casting. Rappers Common and the Game make strong impressions as mysterious menaces, Cedric the Entertainer scores as a nervous drug dealer, and Laurie owns every scene.

Ayer understands that conviction, velocity and adrenaline count for more than intellect in stories such as this. He doesn't develop a distinctive action aesthetic like William Friedkin or Sam Peckinpah, but he's proficient at making us jump with jittery whiplash editing. He regularly steers his characters into bombastic gun battles and propulsive foot chases through ratty 'hoods that the Los Angeles Tourist Authority would rather keep under wraps. With all those bullet holes punching through the sets -- and the actors -- who's going to quibble about gaps in the plot?

Colin Covert • 612-673-7186