In the Midst of Death by Lawrence Block
This time hard-drinking ex-cop Matt Scudder is roped in to an NYPD internal investigation that has ended up with one detective in the slammer on a murdre rap. Jerry is as clean as the world would like him to be although Matt isn't too sure, after all, he was only keen to dish the dirt on his former colleagues as a way of saving his own skin when caught on the take.