The Autobiography of F.B.I. Special Agent Dale Cooper is a book by Scott Frost following the huge success of the Twin Peaks television series.
It is a collection of transcripts from Agent Dale Cooper's audio tapes, from his childhood to the day he is assigned to Laura Palmer's murder. The book includes Dale's upbringing in Philadelphia, family, education at Quaker institutions Germantown Friends School and Haverford College, first stumbles with love, obsession with the FBI, and the relationship between him, Windom Earle, and Earle's wife, Caroline. Many of these tape transcripts are dictated to "Diane," though a later tape states that Cooper enjoys the thought of Diane listening to his tapes so much that he will address all tapes to her, whether she will ever listen to them or not.
In the book, Teresa's body is found in a ditch, she worked at Cross River Café and she lived in a lakeside cabin, none of which is true in the film.
In the book, Cooper investigates Teresa's murder. In the film, the case is assigned to Chester Desmond and Sam Stanley. It was originally planned for Cooper to investigate in the film, but Kyle MacLachlan wished to have a smaller role.