What is the author's style in Trace by Patricia Cornwell?

Trace has two parallel, linear story lines, tied together by a common villain. The major plotline is Dr. Kay Scarpetta's investigation of the death of fourteen-year-old Gilly Paulsson. The secondary plotline centers on Lucy Farinelli's quest to find the stalker who attacked her girlfriend, Henri. The villain in both cases is Edgar Allan Pogue. His story begins in Chapter 2 and continues throughout the book. Although all three stories are interconnected, the two parallel plotlines and the story of Edgar Allan Pogue never quite merge together. The author never places Lucy and Scarpetta in the same location, a plot element made possible by their estrangement. Edgar Allan Pogue's actions obviously affect and in fact drive, both of the parallel plotlines and yet he does not meet Lucy or Scarpetta in person at any time during the novel. He has a history with both women that is recounted in flashback, but Pogue does not interact directly with either one of them.