Street Kings (2008)

Keanu Reeves stars as Tom Ludlow, a veteran LAPD cop who finds solace in the bottle after the death of his wife. When evidence implicates him in the execution of a fellow officer, he is forced to go up against the cop culture he's been a part of his entire career, ultimately leading him to uncover an exortion conspiracy that runs deep with the department.

Official website: http://www.foxsearchlight.com/streetkings/