First degree / David Rosenfelt.

Enhanced descriptions from Syndetics:

The mysterious legacy of defence attorney Andy Carpenter's late father has made him a rich man - 22 million dollars rich, to be exact. But as Andy relaxes in his office, imagining ways to spend his money, he has an unexpected visitor: a stranger who confesses to decapitating and burning a man - coolly relaying on the confidentiality of attorney-client privilege. When an innocent man is charged with the crime, Andy decides to take on the case. But the case becomes personal when, in a stunning development, Andy's client is exonerated and his girlfriend, Laurie Collins, is accused of the crime. When the man who originally confessed to the murder turns up dead, Andy realises that this is much bigger than one crime. Who committed the murders? Who framed Laurie? In the case of his life, Andy must prove Laurie's innocence in this thrilling mystery from the always inventive David Rosenfelt