Fidelity - Thomas Perry

When, despite all his training and twenty-five years experience as a private detective, Phil Kramer is shot dead on a quiet suburban south California street his wife and partners think it had to have been a professional hit.But why target Kramer? As far as they know he hadn't been working on any case that carried that kind of threat. As his wife leads the investigation into his death she realizes that Phil's life was riddled with secrets he kept from her and his colleagues. And buried amongst them is the secret that cost him his life and now threatens hers.