Rampart is a film that would crumble in on itself without a towering main performance to keep it all together. Woody Harrelson plays Dave Brown, a corrupt cop working in Los Angeles in the late 90s, who is under investigation for assaulting a criminal when new evidence resurfaces that links him to a murder committed years before. It's being billed as a hugely controversial role, something akin to Harvey Keitel's in Bad Lieutenant, which is a massive overstatement, but it's a powerful role nonetheless and Harrelson deserves most of the credit being given him.
The story begins to really deteriorate as the film runs on, though, and it's easy to get lost when director Moverman shoots without a real sense of time or context. The story has a way of taking its time when it should be hurrying and vice versa. There's a lot to take in, even though little of it matters in the end, and characters come and go so quickly it's difficult to figure out who the main players are. It doesn't help that the ending is totally unfulfilling and strikes the same kind of frustrating note that The Sopranos did a couple years ago, a trend that's become remarkably popular in film these days. There's not really a sense that Brown is a real character – he has no arc and Moverman seems to be content having him run around in circles and snarl at people a la Clint Eastwood. Still, the scenes with him and Ice Cube, who is just as good here as he was in Three Kings, are so fun to watch you'll forget for a second that he's really just playing a generic bad cop.
Sigourney Weaver and Cynthia Nixon both dominate what little time they get on screen and Foster is serviceable as a strung-out informer. Moverman's stylish and inventive enough as well, and it's to his credit that he keeps the camera glued to Harrelson for most of the film. Ultimately, though, after the credits have rolled, you'll remember another committed performance from Woody ... and not much else.