Damage Control
Robert Dugoni

But bad things happen in threes, her mother has told her. When Dana discovers her husband cheating, she throws herself headlong into the investigation. Delaying cancer treatment, she teams with an intuitive detective to find the link between a one-of-a-kind earring found in her brother's bedroom and a mysterious girlfriend no one seems to be able to identify. But those connected to the murder are beginning to turn up dead, the evidence trail is growing cold and someone is masquerading as a police officer, cleaning up the details as they go along.