You may have seen a recent film with Nicholas Cage called Bad Lieutenant, well that was actually meant to be the sequel to this Harvey Keitel masterpiece (the later film being a not-masterpiece!)
Keitel plays a corrupt cop who spirals downwards into illegal gambling and lots and lots of drug taking. This guy is precisely the sort of guy you don’t want being in charge of public safety.
The film remains very controversial with its explicit central case surrounding the rape of a young nun in a church. Whilst by today’s standards (after crime erotica like CSI special Victims et al) it is fairly tame, it still retains the bite that garnered it both the praise of critics and the swoons of wowsers when it was released in 1992.