‘Police’ (NR)

At its best, "Police" seems like a contest between its director, Maurice Pialat, and its star, Gérard Depardieu, as to who can be more recklessly inventive. Though it trails off markedly toward the end, "Police" is the kind of eccentric and innovative film that has become almost extinct in recent years -- sometimes for better and sometimes for worse, it always surprises.

Depardieu plays Mangin, a Parisian detective of mercurial moods, alternately brutal, tender and playful. Investigating a band of Arab drug dealers, he meets Noria (Sophie Marceau), a sulky brunet who intrigues him almost instantly, almost imperceptibly. Together with his pal Lambert (Richard Anconina), the mob's lawyer, he gets drawn into a caper involving Noria, a bagful of heroin and 200 grand in cash.

But the story is much more complicated than this, shaggy with detours, cameo players (including Sandrine Bonnaire from Pialat's "A Nos Amours," as a call girl) and odd bits of color. Pialat infuses "Police" with a documentary texture -- shooting with a hand-held camera that dances to follow the chaotic action, jumbling dialogue, editing with a nervous, energetic style.

Most of all, though, the realism of "Police" comes from Pialat's characteristic emphasis on improvisation, and the chief beneficiary of the approach is Depardieu. With his head slung forward from massive shoulders and his broad, hanging gut, Depardieu moves through "Police" like a Brahman bull swaying on a slaughterhouse meat hook, and he exudes the usual Depardieu charm -- an animal geniality that reliably bursts into violence. But the improvisation liberates a looseness in Depardieu and lets him channel his aggressiveness into comedy -- he's like the Don Rickles of the station house. Depardieu seems like a tennis champion gracefully batting back everything the unpredictable Pialat tosses his way. His performance is electric with the joy of responding to the challenge.

Depardieu's best moments come with Anconina, whose large, mournful nose anchors a catalogue of wry expressions. For both of them, the cops-and-robbers stuff is a game, and both enjoy playing both sides of the fence -- they live fast and high like the bad guys. And the thin line between cops and criminals is the theme uniting the otherwise diffuse first hour of "Police."

The movie takes a radical, and regrettable, turn two-thirds of the way through, however, when Pialat transmutes his fascinating look at police procedure into a lonely guy movie. Through long takes shot in tight close-up, Depardieu unburdens himself to Marceau, and passionately kisses her for what seems like hours in the front seat of a car (is Paris really New Jersey?). The misbegotten idea seems to be to show the hurt and anguish underlying Mangin's machismo, but this psychological realism comes so late, and is so at odds with the atmospheric realism, that you feel someone has changed the channel. And for once, you don't really want to know why a hero does what he does. In the case of Depardieu, it's much more fun just watching him do it.

"Police" is unrated and contains nudity, profanity and violence.