Yes, you should see it: it's great!
Funny dark hard-boiled crime comedy written & directed by Shane Black, staring Robert Downey Jr. & Val Kilmer. Adapted from a Brett Halliday, (né Davis Dresser; born in Chicago, died in Santa Barbara, wrote a ton in between) novel. Loved it!
Writer James Ellroy has made a career of dirty cops, and Woody Harrelson delivers the most compelling characterization of corrupt law enforcement since Russell Crowe's Wendell "Bud" White of L.A. Confidential. From The Messenger (2009) team of Harrelson, Oren Moverman and Ben Foster. Bleak.