"He does feel very confident and is willing to go to trial if necessary," Arnot said.
In a news conference last month, District Attorney Robert Morgenthau said the screenplay described Halderman's one-page story proposal a scenario in which Letterman's world would "collapse all around him" and would lead to a "ruined reputation."
Morgenthau said the screenplay "covers all the necessary facts" to indict Halderman for attempted grand larceny.
Halderman lived until recently with Stephanie Birkitt, who had previously been a personal assistant to Letterman. Public documents indicate that Birkitt and Halderman lived together in Norwalk, Conn., from August 2005 to August 2009. Birkitt now has an apartment on Manhattan's Upper West Side.
Halderman has been married and divorced twice, according to public records. He had two children with his second wife, and has three stepchildren. His former wife won custody of their children and now lives in Colorado.
Divorce records show that Halderman was ordered to pay $6,800 a month in alimony and child support, starting May 1, 2004.
Halderman has been suspended from his job as the investigation continues.