Die in Plain Sight by Elizabeth Lowell

Suddenly Lacey's investigation into the life and death of the enigmatic artist is leading her down an ever-darkening road paved with lies, blood, and devastating secrets. It also leads her to Ian Lapstrake, a security specialist employed by the appraisal house Rarities Unlimited, who has taken an interest in Lacey's inheritance . . . and in her safety. Because someone wants to prevent Lacey Quinn from examining her grandfather's work too closely, by any means necessary. And clues to a series of horrific, unexplained killings may be hidden in the brushstrokes-clues that have now indelibly marked Lacey and Ian for death.