The pleasure of undercover-cop movies lies in watching police officers turn themselves into actors. By posing as criminals pretending to be something they're not these fearless law enforcers suddenly seem one step closer to all us armchair thrill seekers in the audience, for whom watching a violent crime flick is really an intricate act of fantasy (''Gee, what would it be like to poke a Magnum in someone's face?''). In the new thrillers Deep Cover and White Sands, the lawmen heroes slip so far into their fake-criminal roles that they begin to lose sight of their own identities. These movies revel in what might be called the metaphysics of going undercover: They're about the hazy line that separates cops and crooks, honor and expedience.
It's not often you see a genre movie as stylish and impassioned and as confusingly told as Deep Cover. Directed by Bill Duke (A Rage in Harlem), this brooding cop-thriller psychodrama follows the slow descent of an idealistic black officer, Russell Stevens Jr. (Larry Fishburne), who is tapped by the DEA to infiltrate a Latin American drug cartel that has cornered the Los Angeles cocaine trade. As Stevens rubs shoulders with sleazebags like David Jason (Jeff Goldblum), a ''respectable'' lawyer and drug supplier who harbors fantasies of marketing synthetic cocaine, the movie seems to be setting up a dense network of loyalty and treachery.
Duke is out to blend the commercial, gut-wrenching pleasures of an inner- city shoot-'em-up with the complex moral rage that marked such black-cinema touchstones as Sweet Sweetback's Badasssss Song (1971). For all his craftsmanship, though, there's a nagging oddity about Deep Cover: The movie unfolds in such a jagged, pell-mell fashion that you have to stop and get your bearings in almost every scene. Duke keeps letting his sociological ''observations'' dictate the action, rather than the other way around. Still, if his film fails as narrative, it succeeds, to a point, as a kind of stylized fever dream. Stevens sinks deeper and deeper into the corrupt L.A. night world, until it becomes clear that, even as a cop, he's betraying his cause and his people. The movie peels away every layer of hope, revealing a red-hot core of nihilistic despair. Fishburne, with his hair-trigger line readings and deadly reptilian gaze, conveys the controlled desperation of someone watching his own faith unravel. And Goldblum reveals a new dimension of comic rottishness. If Duke could ever harness his explosive vision to a truly compelling story, he might come up with a winner.
White Sands, on the other hand, is a dud, the sort of movie that swathes its emptiness in layers of chic, swirling ''visuals.'' Willem Dafoe stars as a . small-town New Mexico sheriff who discovers a corpse and a briefcase containing $500,000 and takes the dead man's place in order to see where the money leads. Along with the usual corrupt federal agents, White Sands offers such swank absurdities as a trust-fund princess (Mary Elizabeth Mastrantonio) who participates in black-market weapons deals in order to fund ''worthy causes'' and Mickey Rourke as a suave arms salesman who...well, does it even matter who Mickey Rourke plays these days? Dazed and imperious, his puffy tan skin set off by teeth the color of Wite-Out (did he lose his real ones in the boxing ring or is this simply the worst bonding job in show biz?), he has become a painfully hammy icon of sleaze: the undead Method Actor. As Dafoe sets his enemies against each other, slipping from good guy to betrayer and then back again, White Sands turns into a series of plot twists so abstract and monotonous that the movie, in the end, is about nothing more than its own wheel-spinning convolutions. Deep Cover: B- White Sands: C-