Showing A Darkness More Than Night by Michael Connelly

When a small-time criminal is found dead, former homicide detective McCaleb is persuaded to profile the killer. Six years ago the victim had been arrested by Harry Bosch for murder but was later released uncharged. McCaleb picks up a clue the sheriffs missed, and discovers that the killer left a message at the crime scene - a message that seems to implicate Bosch...

Meanwhile Bosch is in the midst of a high stakes trial being covered in the press by Jack McEvoy. Bosch was lead investigator on a murder case that saw the arrest of the son of a wealthy and powerful man. As the trial progresses the defence strategy becomes clear: put Bosch on trial instead of the rich kid. McCaleb and Bosch, first at odds, must now work together to clear Harry's name.