Down the River Unto the Sea by Walter Mosley
Winner of the RBA Prize for Crime Writing Joe King Oliver was one of the NYPD's finest investigators until dispatched to arrest a well-heeled car thief, he is framed for assault, a charge that lands him in the notorious Rikers Island prison.
A decade later, King is a private detective, running his agency with the help of his teenage daughter, Aja-Denise. When he receives a card in the mail from the woman who admits she was paid by someone in the NYPD to frame him all those years ago, King realizes that he has no choice but to take his own case: figuring out who on the force wanted him disposed of - and why.
At the same time, King must investigate the case of black radical journalist Leonard Compton, aka A Free Man, accused of killing two on-duty police officers who had been abusing their badges to traffic drugs and women into the city's poorest neighborhoods. In pursuit of justice, our hero must beat dirty cops and even dirtier bankers. All the while, two lives hang in the balance: Compton's, and King's own.