Diane is FBI Special Agent Dale Cooper's secretary to whom he dictates all of his tapes.
Diane was assigned as Cooper's secretary on his first day working for the FBI, December 19, 1977. He described her as an "interesting cross between a saint and a cabaret singer," and addressed most of his tapes to her from that moment on, even ones where he appeared to be talking to himself.
She appeared to show concern for Cooper, as she sent him flowers during his absence after taking a life for the first time.
One day in early 1988, Cooper stood outside of Diane's office and mentioned that she had not changed her hair and was wearing a dress she had worn before, but he noticed that she has indeed changed something in the room. He took a moment to figure it out and excitedly noted that she moved a clock twelve inches to the left. Before leaving, he requested a "damn great pot of coffee" made from Sally's ground coffee.
Diane joined Cooper for a Chinese food dinner on June 10, 1988, and he noted the next day that despite having known her for over 10 years, he did not know her last name.
Special Agent Cooper . . . Dale and I had dinner once. We ate Chinese. We had wonton soup, egg rolls, and Peking duck. That's the one where they inflate the bird with air, swelling it to over double its original size. Without a doubt the most delicious skin I've ever eaten, firm and at the same time delicate. And the meat itself takes on a flavor when slid into the mouth. . . . Well, I couldn't get enough of it.
Behind the scenesEdit
Diane has, to date, never appeared on-screen. However, there does exist a quote attributed to her in The Autobiography of F.B.I. Special Agent Dale Cooper: My Life, My Tapes.