Joseph Wambaugh 
Blue Knight [EPUB ebook] 

Bumper Morgan is a cop, a patrolman with twenty years’ service under his belt and retirement is looming ominously close. His outlook is old-fashioned: he believes in justice — even when it doesn’t conform to the letter of the law. If a judicious bit of violence will give him what he needs to solve a crime, so be it. That’s the way the game’s played. And it usually works. Until the prospect of retirement clouds his judgement and Bumper finds himself starting to make mistakes. The kind of mistakes that kill people.