IN THE POPULAR imagination Los Angeles has long been the city of the American Dream—a land of openness and opportunity where people can reinvent themselves and realize their highest economic and spiritual potential. The guardians of this earthly paradise, the Los Angeles Police Department (LAPD), once held similar mythic status in TV series like Dragnet and the novels of Joseph Wambaugh (The New Centurions). Unlike their flabby east coast or Midwest counterparts, they were honest, clean-cut, physically fit protectors of law and order. A pro-active, gung ho, elite unit like the Marines or the Green Berets, they drove the Mafia out of town and kept the streets safe from bad guys.

All that changed six years ago with the much-publicized Rodney King incident. Since that time the LAPD's detractors and much of the media have characterized the department as racist, ultra-violent, and out of control—and claimed it had always been so.

LA Confidential, based on James Ellroy's novel, reflects the current ACLU, left-liberal view of the LAPD as influenced by that incident. It's the flip side of Dragnet's idealized knights in blue and just as stylized and false. Every cop in LA Confidential is either venal or corrupt; systematic discrimination against minorities is depicted as part of the department's culture; and the beating and killing of suspects is a regular occurrence. It's a nightmare vision of law-enforcement authority run amok.

The movie is set in 1953 when the city's future looked bright, and a brief prologue presents images of an optimistic boomtown. But writer-director Curtis Hanson (The Hand That Rocks the Cradle) and co-screenwriter Brian Helgeland (Conspiracy Theory) soon rub our noses in the dark side. The story revolves around three policemen, each of whom represents a different aspect of LAPD corruption.

Sgt. Ed Exley (Guy Pearce) at first glance appears to be a law-enforcement officer in the squeaky-clean New Centurions mode. The college-educated son of a hero cop killed while on duty, he refuses bribes and fights against the department's racism. When the chief (John Mahon) advocates the use of “all available force” to track down some black suspects, Exley cracks, “Why not just put a bounty on them?”

The straight-arrow exterior hides an ambitious, manipulative careerist with few moral scruples. When a gang of his fellow cops brutally stomp some Mexicans in the police station on Christmas Eve, Exley tries to stop them. During the department's internal investigation he agrees to break the code of silence and testify against his brother officers-for a price. Knowing his action will allow the brass to put the best possible face on the incident, he demands a promotion to detective lieutenant in return for his testimony.

Bud White (Russell Crown) is a vigilante cop who believes policemen must “do what they have to do for justice.” Whenever he sees a woman being abused, he punishes the perpetrator regardless of the law. In one incident, he executes a rapist, then plants evidence to make it look as if he acted in self-defense.

Sgt. Jack Vincennes (Kevin Spacey) is the slimiest of the lot. Nicknamed “Hollywood Jack” and “the Big V,” he works as an adviser to the Dragnet-like series, Badge of Honor, which presents the LAPD in the best possible light. He makes money on the side by setting up marijuana busts of young stars and starlets so they can be photographed by Sid Hudgeons (Danny Devito), editor of the celebrity-driven tabloid, Hush-Hush, whose material is always “off the record, on the q.t., hush-hush … prime sinuendo.”

Vincennes and White hate Exley because he snitched on their buddies. The three of them are forced to work together though, on the department's biggest case, The Nite Owl Massacre—a coffee-shop killing of six people including an LAPD officer. Exley appears to wrap-up the investigation after a bloody shoot-out for which he is decorated, but none of the three men is satisfied. There are too many loose ends.

White's damsel-in-distress syndrome has gotten him involved with Lynn Bracken (Kim Basinger), a hooker with a heart of gold who has been surgically altered to look like film heroine Veronica Lake. The trio's off-the-books investigation leads to her pimp (Pierce Patchett) who is described as “a powerful, behind-the-scenes strange-o.” This results in Exley's own affair with Bracken, which turns White against him.

A labyrinth of tantalizing clues pulls the trio back together onto the case, and each redeems himself in the pursuit of justice. By conventional standards, they all have enough negative character traits to be the bad guys in most cop films. As we watch them become enmeshed in the LAPD's pervasive culture of corruption, it seems unlikely that any of them will become clean. But each has confronted some example of evil-doing that viscerally disgusts him and turns him against the department.

This drama of redemption is emotionally gripping if you can get past the excessive violence and profanity that the filmmakers use to spice things up. You root for the three police officers to do the right thing even though they're risking their lives. Their commitment to the truth allows the movie to transcend its trendy, anti-cop attitudes and amoral, cynical veneer. Almost in spite of itself, LA Confidential reaffirms the power of individual conscience to make a difference.

The USCC classification of LA Confidential is A-IV-adults, with reservations. The movie is rated R by the Motion Picture Association of America.

John Prizer, the Register's arts and culture correspondent, is based in Los Angeles.