Redemption by David Baldacci

Redemption is the newest Amos Decker ("Memory Man") novel. Decker has gone back to his old hometown in Ohio to visit the graves of his wife and daughter when he crosses paths with a man he sent to prison for a quadruple murder years earlier, when he was a new cop. The man is now dying and wants Decker to prove that he was innocent all along. When Decker starts looking into the case, he realizes he made a lot of rookie mistakes and the man might actually be innocent. Then people start trying to kill him, which makes Decker believe he has opened up a whole can of worms by starting up the investigation. As always, Baldacci tells a good story with compelling characters.