It looks like the blackmailer's source was Stephanie.
Robert J. "Joe" Halderman, a producer for the true-crime show "48 Hours," pleaded not guilty in a Manhattan court as he was arraigned on one count of attempted first-degree grand larceny, punishable by five to 15 years in prison. Bail was set at $200,000.
Halderman's connection to Letterman was not immediately clear, but public records show that until August, he lived in Norwalk, Conn., with Stephanie Birkitt, a 34-year-old woman who works on the "Late Show" staff and used to work at "48 Hours."
Birkitt was an assistant to Letterman on the "Late Show" and frequently appeared on camera with the host in comedy bits. Last month, Birkitt moved to Manhattan's upper West Side. There was no answer Friday at a phone listed in her name.
It was also unclear how many women were involved in relationships with Letterman. All of the affairs took place before Letterman's marriage, said Tom Keaney, spokesman for Letterman's production company, Worldwide Pants.
CBS issued a statement Friday: "We think it was appropriate for Dave to disclose the matter publicly as he has, and we are continuing to cooperate with authorities."