A CBS producer accused of blackmailing David Letterman used pages from his assistant's diary that described an affair with the late night funnyman, a law enforcement official revealed today.
The assistant, Stephanie Birkitt, worked on the "Late Show" and lived in Norwalk, Conn., with Robert Halderman until August, officials said.
Law enforcement officials said Halderman copied Birkitt's diary, which contained details of her affair with Letterman, and tried to use it as blackmail fodder.
The official spoke on the condition of anonymity because the investigation is ongoing.
Birkitt was an assistant to Letterman and frequently appeared on camera with the host in comedy bits.
The new revelations about the alleged plot come after Halderman's attorney said Letterman is a "master at manipulating."
"He's a master at manipulating audiences, that's what he does for a living," Gerald Shargel, attorney for accused extortion suspect Robert "Joe" Halderman, said on the "Today" show.
Shargel went on a media blitz this morning to defend Halderman -- who has pleaded not guilty to charges of grand larceny in Manhattan criminal court on Friday.
Letterman made a stunning on-air revelation last week that he was blackmailed for having sex with staffers. Shargel said that's only part of the story.
"I'm here to say, 'Not so fast,'" Shargel said on ABC's "Good Morning America." "I look forward to cross examining David Letterman because I don't think the full story is before the public."
If Halderman -- who was arrested after he allegedly tried to cash a $2 million check made out to him by Letterman -- wanted to extort money from the funnyman he would have asked for cash, Shargel said.
“I’m not about to share more information on day four of the case, but I will say this, the case that has been put forth by the prosecution makes no sense. In the history of extortion there has never been a case of someone paying by check,” Shargel said on the "Today" show.
The attorney spoke out as sources told the New York Post that Halderman may have been motivated by the late show host's own grudge against him.
When Halderman started dating Letterman's personal assistant, the funnyman essentially banned Halderman from any "Late Show " office parties and staff events, the Post reported, citing sources.
"He wanted Stephanie there, not Halderman -- he didn't like him," a source told the paper.
Halderman, an Emmy-award winning producer for CBS, had little in common besides Birkitt, according to Post sources which characterized the Halderman as a guy who liked to "live well and party hard," and Letterman as "private, reserved and geeky."
It has also been speculated that Halderman was desperate for money, as a result of that lifestyle and a financially crushing divorce settlement.
Sources told the paper Halderman and Birkitt broke up six months ago after tensions grew over her desire to have kids, and his desire not to.
After the breakup, Birkitt allegedly claimed to Halderman that she had once had a fling with Letterman, further enraging the producer, according to the Post.
Meanwhile, Letterman gets back to work this afternoon, and many critics wonder how his revelations of workplace trysts will go over with women viewers.
There are still many unknowns following Letterman's startling admission last week: How many women were involved? Did the relationships end well? Did women feel pressured by the boss' advances, or were they happily consensual? Did any other staffers feel the way to get ahead was through Letterman's bed? Are women who did not have intimate relations with Letterman upset that those who did may have gotten special treatment or career advances? Is anyone talking to lawyers?
All could determine whether Letterman is significantly damaged or if it's just a footnote to his career.