What is the author's style in Case Closed: Lee Harvey Oswald and the Assassination of JFK by Gerald L. Posner?

Case Closed by Gerald Posner is a well-structured, highly readable book. He divides the book into nineteen chapters and each has a title, and each chapter covers a relevant topic. In the Afterword, Posner examines the information that has become available in the ten years since he first published the book, explaining why his conclusions have not changed.