What is the author's style in The Return of Martin Guerre by Natalie Zemon Davis?

The point of view of this book is third person. The author talks about people as the narrator. Occasionally, the author and narrator speaks of herself in the first person. From the third person, the author describes the lives of Martin Guerre, Bertrand, Pierre and Arnaud du Tilh. The point of view is not omniscient, but that of an investigator, since the author's information is based on historical record and much of it is uncertain. Due to the large amount of speculation by the author, the tone of the book is somewhat aloof and academic at times, at other times the tones takes on the feel of a news report. It is an investigation of a mystery, the theft of the identity of Martin Guerre, and what happens, from the standpoint of a person living hundreds of years later. All comments on the psychological state of the characters are educated guesses by the author.