According to Captain Nascimento (Wagner Moura), the narrator and dramatic catalyst of José Padilha’s fiction film debut “Elite Squad,” on the mean streets of modern-day Rio de Janeiro, “the drug gangs and the police had to work out ways to get along.” The captain, leader of a cadre of the titular paramilitary cops called BOPA, initially presides over a flashy but quotidian cinematic tour of Rio after dark, rendered in a style and tone similar to the kinetic view of Brazil’s urban underworld in 2002’s “City of God.”

Mr. Padilha’s film, which opens Friday at Landmark’s Sunshine Cinema, was, in fact, co-written by the Oscar-nominated author of “City of God,” Braulio Mantovani, and both pictures share the same film editor. But where “City of God” periodically stepped back from the fray to offer high-minded social commentary, “Elite Squad” details a breach in the fragile balance of crooks — mostly corrupt cops — and the terrified middle class with a ruthlessly economical, no-frills narrative energy that is more analogous to an American B-Western or a 1970s American policier than to an exotic regional docudrama.

Nascimento, you see, is a classic burnt-out case. Though barely halfway through his 30s, the BOPA leader is plagued by stress (a word that, as it turns out, translates literally into Portuguese), in addition to related physical and psychological symptoms, and is gravely concerned that he will not live to see his unborn son grow to school age. Survival dictates that the captain hang up his guns and badge and resign from the Brazilian police’s shock troops. But loyalty to BOPA’s cultish, above-the-law sanctum obliges him to find a worthy replacement. The problem is that the regular Rio PD hiring pool from which BOPA recruits is a septic tank of graft and payoff opportunism.

Promising new blood arrives in the form of a pair of rookie police cadets. Though childhood friends Matias (Andre Ramiro) and Neto (Caio Junqueira) are well matched as idealists, they exercise their ethical ambitions in very different ways. Matias studies criminal law among sanctimonious, cop-hating students who would shun him if they knew about his day job. Neto, meanwhile, chooses to turn the Rube Goldberg-like payoff mechanisms of Rio’s crooked police force to his unit’s advantage, rather than lining his own pockets as his superiors line theirs.

A BOPA cavalry rescue of the two eager rookies earns them spots on the Elite Squad’s invite-only recruitment short list, and eventually a trip through a training course so arduous that, by rights, the facility ought to have been named Camp Be Careful What You Wish For. Meanwhile, Matias’s burgeoning romance with a comely fellow student named Maria (Fernanda Machado) is complicated considerably by the fact that she doesn’t realize her boyfriend’s interest in her slum outreach work has much to do with the fact that he’s a cop.

Though shot through with state-of-the-art, smash-and-grab camera pyrotechnics, pulsing music, and gangsta histrionics, “Elite Squad” is, at heart, a throwback to the kinds of cop-and-cowboy movies that American film producers seem to have given up on making in Hollywood. Like Ricky Tognazzi’s similarly lean and stealthily retro 1993 Sicilian cop drama “La Scorta,” “Elite Squad” moves on its characters’ adrenaline, not on the dubious artificial energy of the digital explosions, close-ups of cell phones and computer screens, and gravity-defying action set pieces that continue to elicit yawns in most Yankee cop movies.

Mr. Padilha’s prior documentary experience serves him well. “Elite Squad” has the loose but accurate feel of work shaped as much on-set and in the cutting room as at the typewriter. The participation of co-writer Rodrigo Pimentel, a longtime veteran of BOPA and the Rio PD, also appears to have brought much in the way of authentic detail. The film’s day-to-day view of the practical workings of corruption in law enforcement (in one scene, a patrolman is obliged to bribe his desk sergeant to reschedule vacation time) is intriguingly unsensationalized and believable. Indeed, when released in Brazil (initially via a widely circulated pirated copy), “Elite Squad” generated substantial controversy concerning the relative realism of the acts of violence and procedural misconduct it dramatizes.

The cast, an ingratiating mix of experienced actors and raw big-screen recruits, has also been favorably assembled with an eye toward interpreting separate layers of social strata with equal verisimilitude. Mr. Moura, in particular, rises to an occasion that would incline lesser performers to grit their teeth, tighten up their body armor, and growl their way through to the credits. We can feel why Captain Nascimento does what he does, whether eagerly suffocating suspects with a plastic bag or watching himself fall apart in his own bathroom mirror, and we appreciate just how selfish and exploitative a career assist can be when it’s given for the sake of the promoter and not the promoted.

On the heels of recent, cliché-driven American cop dramas such as “Righteous Kill,” “Elite Squad” is a reminder that when it comes to good examples of the gun-and-badge genre, it’s not that they don’t make them like they used to; it’s that, outside of HBO’s “The Wire,” they just don’t make them here.