He's accused of seeking to shake down the late night star for $2 million, threatening to make public information about Letterman having sex with women who worked for his show. Halderman has pleaded not guilty to attempted grand larceny counts and is free on 200,000 dollars bond, awaiting a scheduled Nov. 10 court appearance.
Letterman revealed on the air last week that he had indeed had sexual relationships with staffers.
Thursday's New York Post quotes sources as saying Halderman caught his then live-in girlfriend, Stephanie Birkitt, making out with Letterman as recently as August.
The Post says it happened while Letterman and Birkitt were in Letterman's car parked in the driveway of Halderman's home in Connecticut. And, says the Post, Halderman and Birkitt broke up a short time after that supposed incident.
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The tabloid says Letterman often drove his 34 year old assistant to the home she was sharing with Halderman.
With rumors swirling that Birkett has been banned from the set of "The Late Show with David Letterman," sources at the show tell CBS News she is actually on a paid leave of absence, and "The allegation that she's been banned from the building (is) completely untrue."
On Wednesday, reports CBS News Correspondent Bianca Solozano, Halderman was approached by reporters at his home for a statement. He said, "I know you have a job to do. I might as well make it easy on you guys. It's a beautiful day. I have some errands to run."
Letterman, who failed to specifically reference the extortion plot on Wednesday night's show, has seen the comedic tide turn somewhat. Politicians once ripe for his late night fodder, such as embattled South Carolina Gov. Mark Sanford, are giving the funnyman some advice of their own.
Sanford remarked, "There's a lot more introspection and soul-searching on the way down than there is on the way up."