And now, the ugly details! As previously reported, the man arrested for Letterman's alleged extortion is Robert "Joe" Halderman, a producer for CBS's 48 Hours (see his glamorous head shot, at right). TMZ says he was popped outside of CBS HQ yesterday for attempted grand larceny in the first degree. Reports last night said he was living with one of the women with whom Letterman has admitted an affair — and he was, it turns out!
Fox 5, which saw the arrest warrant, says that woman was Stephanie Birkitt, Dave's former assistant, who used to appear on the show all the time (see clip below). Radar Online says that Letterman and Birkitt did have a sexual relationship, but it happened before the birth of Dave's son in 2003 (though the affair took place while Dave was living with Regina Lasko, who he married in March of this year). Halderman shared a home with Birkitt until recently, and the envelope he put in Letterman's car, according to the warrant, contained "parts of her diary and personal correspondence." Radar reports Halderman used the materials without Birkitt's knowledge, and that she's "mortified" today. It's still unclear whether Halderman had evidence of multiple affairs, which Letterman admitted to last night, but Dave probably smartly figured he'd put everything out there just in case.
Via Radar, here's a clip of one of Birkitt's Late Show appearances: