Line of Fire by Stephen White

Line of Fire - Several years ago, Sam Purdy and Alan Gregory were threatened by Justine Winter Brown.  Brown had also threatened their children's lives.  Sam took matters into his own hands. Frederick police ruled Brown's death was ruled a suicide.  Today, the Frederick police have reopened the case and Alan's wife Lauren has been asked to investigate Boulder's connection to Brown.  Alan has a new patient, Amanda, who is the mistress of two men, one who she believes is suicidal.  Another new patient is a car accident victim that Sam had named Sleepy Doe, because they didn't know his name, and he was unconscious.  This patient begins to threaten Alan with what he heard while he was in a coma.