Keitel is the Bad Lieutenant, a nameless cop forced by circumstance and ill-judgement into a spiral of decay and depravity. He gambles on the ball-games, invariably losing, but each time convinced enough to double the bet. He drops his kids at school, then takes time out to snort a few lines before facing the day. He purloins evidence to sell to drug dealers, drinks like a fish, and indulges in orgies - this is one very Bad Lieutenant indeed. And one going even further down until a nun is viciously gang-raped on the altar of her church and refuses to finger her assailants, claiming to have already forgiven them. The reward offered would give him a way out of his crazily escalating debts, but other, deeper sensibilities are awoken and the Bad Lieutenant sees a shot at his own spiritual redemption.

In essence this is a mood piece, plot elements are kept to a minimum and the script by the director and Zoe Lund concentrates on a detailed portrait of a man living his own nightmare. And in Keitel, Ferrara finds an actor willing to go the extra distance for the role. Bloodshot eyes stare out of the increasingly gaunt face giving some notion of the man behind, one struggling with the revulsion of the place in which he finds himself, but quite incapable of escape; this isn't a bad man, but a man forced to do bad things. Keitel snorts lines like a vacuum cleaner, shoots up on screen, and looses off his gun with almost reckless abandon. It's a part that starts at the bottom and gradually digs its own grave as Keitel stands naked, arms outstretched, howling into the camera. Ferrara allows his eye to linger painfully as the cop masturbates while verbally abusing two girls caught illegally driving their father's car, telling them that if they do something for him, he'll do something for them. It is the sort of role from which ninety-five percent of name actors would run a mile, but that Keitel seizes with both hands, all the time pushing for that extra distance.

Ferrara made the little-seen and much-misunderstood Driller Killer, as well as proto-feminist revenge thriller Ms. 45 (which featured Lund), and uses much the same grimy, street-level techniques here, making this a far darker and more realistic piece than his last, albeit excellent, drug-gang thriller The King of New York. The problem is that as a film-maker he is much more at home on those mean streets than he is with the religious elements of his tale and notion of redemption, thus the nun's speech of forgiveness is faltering and less convincing than what has preceded it, and the film cannot quite manage the imaginative leap necessary to pull off the vision of Christ that appears to the cop in this, his darkest hour. Undeniable though is that the scene is a tour-de-force for the actor, as for five minutes or so he impotently screams out his rage and agony directly at the audience. It is intense and compelling without ever being gratuitous or showy.

In Bad Lieutenant, Ferrara is making his stab at Scorsese territory (and certainly the last few minutes - the lingering final shot outside the Trump Tower in particular - are more than worthy) and tends on occasion to overplay his hand in a way Scorsese never would. But for all that it struggles here and there, it still remains a astonishingly visceral piece of movie-making, driven at heart by the sort of committed, honest, career destroying performance that would, in a fair world, win every prize going. For many this will be a trip too far, a grossly offensive wallow in the irredeemably seedy, but remains one that should be seen if only for the astounding Keitel who, with this and Tarantino's delicious Reservoir Dogs, unbelievably just gets better and better.