Murder at Swann's Lake — Sally Spencer

Chief Inspector Charlie Woodend and his loyal sergeant tackle a murder with as many suspects as there are clues in this tight puzzler.
 
Swann's Lake, 1960. When Robbie Peterson, a criminal-turned-club-owner, is found dead in his office, a six-inch nail driven deep into his skull, Chief Inspector Woodend and Sergeant Bob Rutter are brought up from London to investigate. Why was Robbie's office broken into twice on the day of his funeral? What caused Robbie's son-in-law to attack his own brother on the night of the murder? As the case unfolds, Woodend uncovers several crimes, but it is only as it draws to a close that he realizes the murder has nothing to do with Robbie's criminal past -- and everything to do with his domestic present.