Diamond dust - Peter Lovesey

With another court case over and a local villain banged up for a few years, Detective Inspector Peter Diamond is keen to get his teeth into another case. So when a call comes in that a woman's body has been found in one of Bath's parks he gets himself to the scene in record time, where he is able to identify the victim as his wife and to establish the fact she's been shot. Mad with grief, Diamond eventually concedes he cannot be an unbiased member of the investigation. Keeping himself away from the team becomes all the harder when he suddenly finds himself under suspicion, and when his colleagues find no case against him but appear unwilling to follow up any of his suggestions - did Steph's previous husband have an alibi - Diamond decides that a little independent action is called for. As well as following his theory that a family of local thugs killed Steph to get at him, he is also intrigued by the fact that the wife of another policeman has gone missing. He'd served with the husband in the Met and they revisit the cases they'd worked on together. Between them they unearth many startling possibilities and some unexpected facts, but it is Diamond who ultimately avenges his beloved wife.