The Big Easy (1986) review

Assistant District Attorney Anne Osborne (Ellen Barkin) is investigating corruption in the New Orleans police department, ends up in bed with Lieutenant Remy McSwain (Dennis Quaid) who she then has to prosecute in court for taking a bribe ... oh, and there are a slew of murders going on around town over drugs (supposedly).  McBride takes an unorthodox approach to familiar crime story material, tilting the material far closer to comedy than drama and dashing in some odd little extras: Quaid's cartoonish and a little over-the-top, the actual Jim Garrison is in there (of JFK fame) as the judge and wide-eyed Grace Zabriskie - always a scene-stealer - plays Remy's Mom.  There's a nice little discussion close to the end about why police officers have this habit of getting on the wrong side of the law (my biological grandfather was a less-than-honest cop) but that sloppy showdown-on-the-docks makes for an unsatisfying ending.