Let It Burn by Steve Hamilton

Let It Burn is part of the excellent "Alex McKnight" series, which is mostly set in Michigan's Upper Peninsula. Burn, however is set in Detroit as Alex goes back to revisit the last case he worked on as a Detroit cop before being shot and taking early retirement. The case involved a young black teen named Darryl. Alex saw him running from the partially abandoned Detroit central train station just around the time a suburban woman's body was found there. After being in prison for years, Darryl is now being released--which gets Alex to wondering whether Darryl was indeed the right man.That leads Alex back to Detroit--and a whole new dangerous journey.

Hamilton gives a vivid portray of the sad state of the Motor City as Alex drives around town mourning the blocks of burned-out houses and shuttered manufacturing plants. And remembering how different things used to be when he was a cop there.