David Letterman's On-Air Apologies Go On

If you are starting to feel the chilly fall weather, take heart. David Letterman told his studio audience that it was far chillier in his home.

"I would give anything to be hiking on the Appalachian Trail," he joked, in a reference to S.C. governor Mark Sanford whose dramatic extramarital affair had been a previous prime target for Letterman.

Letterman continued to use his late night talk show as a platform to discuss how he "has his work cut out for him" in dealing with the fallout from his on-air confession that he was the alleged victim of extortion.

He also made nods to his past bashing of Bill Clinton and Eliot Spitzer by beginning a joke and trailing off before the punchline.

VIDEO: David Letterman apologizes to fansPlay

The audience seemed largely sympathetic, laughing and applauding as he made jokes about how he spent his weekend, "raking his hatemail."

Joe Halderman, 51, an Emmy-award-winning producer for CBS News' "48 Hours," has pleaded not guilty after he was charged last week with trying to blackmail Letterman for $2 million. Halderman allegedly claimed he had evidence of the talk show host's sexual affairs with staff members.

According to a source close to Letterman, the relationships Halderman was allegedly going to reveal occurred before Letterman's March 2009 marriage to Regina Lasko, with whom he has a son, Harry Joseph Letterman.

VIDEO: Letterman Admits to Sex with StaffPlay

During Monday's taping of "Late Show," Letterman, 62, apologized for the unwanted attention that has bombarded his staff.

"I'm terribly sorry that I put the staff in that position," he told the studio audience. "The staff here has been wonderfully supportive to me, not just through this furor, but through all the years that we've been on television and especially all the years here at CBS, so, again, my thanks to the staff for, once again, putting up with something stupid I've gotten myself involved in."

He also talked about how the scandal has affected his relationship with Lasko.

"She has been horribly hurt by my behavior, and when something happens like that, if you hurt a person and it's your responsibility, you try to fix it," he said. And at that point, there's only two things that can happen: either you're going to make some progress and get it fixed, or you're going to fall short and perhaps not get it fixed.

By and large, members of his studio audience were rooting for Letterman. Sort of.

One woman said that while she was "impressed" with the way Letterman was handling the growing scandal and embarrassment, she wasn't handing him any pity points.

"I have sympathy for his wife. You know he's an adult, he made the choice, he put his family in jeopardy. He's got a young son out there, so it's got to be bad," said Hattie Lefkowitz. "But…do I feel sorry for him? No!"

Who is Joe Halderman

Halderman's lawyer, Gerald Shargel, told "Good Morning America" today that Letterman's on-air confession was hardly the final word on the matter.

"Joe Halderman was at CBS for 27 years. Here's a guy who was an investigative journalist for so many years," Shargel said. "To say he was trapped in an extortion plot was kind of preposterous."

Halderman's attorney said that the late-night comedian's talk-show confession did not tell the whole story.

"I'm here to say, 'Not so fast," Shargel said. "I look forward to cross-examining David Letterman, because I don't think the full story is before the public. There's much more to this story." Freed on $200,000 bail, Halderman faces up to 15 years in state prison if convicted.

Letterman's On-Air Confession

Last week, Letterman revealed to the studio audience that he'd received a package three weeks ago containing a threat to reveal those indiscretions if he didn't pay up.

In a press conference last week before Halderman's arraignment, Manhattan District Attorney Robert Morgenthau said Halderman demanded to be paid $2 million in an initial meeting with Letterman Sept. 9, when Halderman allegedly waited outside Letterman's New York City apartment.

Halderman had threatened to reveal "personal and private information" if Letterman did not accede to his demand to purchase a one-page screenplay he presented at the initial meeting, said Morgenthau.

The district attorney said the screenplay described a scenario in which Letterman's world would "collapse all around him" and would lead to a "ruined reputation."

Three subsequent meetings between Letterman and Halderman were recorded by Letterman's attorney, Morgenthau said.

Shargel told "Good Morning America" that he had not yet had a chance to hear the tapes that prosecutors say prove his client tried to extort Letterman, nor read the transcripts.

And while Shargel admitted that Halderman did attempt to cash Letterman's phony $2 million check, "the surrounding circumstances are what's relevant," Shargel said.

ABC News' Eileen Murphy, Michael James, Lindsay Goldwert, Brandon Bodow and Richard Esposito contributed to this report.