Miami Blues by Charles Willeford
After a brutal day investigating a quadruple homicide, Detective Hoke Moseley settles into his room at the un-illustrious El Dorado Hotel and nurses a glass of brandy. With his guard down, he doesn't think twice when he hears a knock on the door. The next day, he finds himself in the hospital, badly bruised and with his jaw wired shut. He thinks back over ten years of cases wondering who would want to beat him into unconsciousness, steal his gun and badge, and most importantly, make off with his prized dentures. But the pieces never quite add up to revenge, and the few clues he has keep connecting to a dimwitted hooker, and her ex-con boyfriend and the bizarre murder of a Hare Krishna pimp.
Chronically depressed, constantly strapped for money, always willing to bend the rules a bit, Hoke Moseley is hardly what you think of as the perfect cop, but he is one of the the greatest detective creations of all time.