Stunned colleagues Friday described veteran CBS News producer Joe Halderman—who was arrested outside the network’s West 57th Street offices Thursday in the alleged scheme to blackmail David Letterman—as a rogue and a womanizer, a lover of literature, a “smart frat boy,” a swashbuckling journalist, and an occasional barroom brawler who distinguished himself in dangerous war zones and occasionally displayed a certain reckless streak.

The 51-year-old Halderman, a top producer for 48 Hours, might have been “cocky” and “arrogant” and lived his life on the edge, said co-workers who have known him for the past two decades, but he certainly didn’t seem capable of the sort of sensational crime that would have made a perfect episode for the CBS magazine show.

“I’m just in unbelievable shock,” said former CBS News executive Marcy McGinnis, who was Halderman’s boss in the London bureau for six years in the 1990s and last saw him a few months ago during one of their regular dinners. “He’s a good guy…It sounds to me like a nervous breakdown of some sort. I feel so badly about this. This is not a bad man. The behavior is so unbelievable, he just must have snapped.”

“Frankly, I couldn’t be more astonished that this guy was involved in something like this than if you came riding through my apartment on a hippopotamus,” said former CBS Evening News anchor Dan Rather.

Dan Rather, who as anchor of the CBS Evening News traveled to many hotspots with Halderman, told me he’d been impressed by the hard-charging producer’s knack for consistently getting the story. “This is obviously a tragedy,” Rather said. “Frankly, I couldn’t be more astonished that this guy was involved in something like this than if you came riding through my apartment on a hippopotamus.”

• Tracy Quan on how the rules of bedding the boss have changed.According to law-enforcement authorities and Letterman’s remarkable account on Thursday night’s Late Show, Halderman demanded $2 million from the television star or else he would go public with Letterman’s flings with female staffers. He was arrested after trying to deposit a bogus $2 million check from the talk-show host. News reports said Halderman was in financial straits, paying alimony to one of two ex-wives, and had been living in Norwalk, Connecticut, in a relationship with Letterman’s former personal assistant, Stephanie Birkitt, a onetime staffer of 48 Hours, who allegedly had been one of Letterman’s workplace lovers. Birkitt, 34 years old, is said to have broken up with Halderman several weeks ago, and is devastated by the scandal.

Today, Halderman pleaded not guilty to attempted first-degree grand larceny, a felony. Susan Zirinsky, executive producer of 48 Hours—who had been working with Halderman on an episode, colleagues say, until minutes before the cops put him in handcuffs and hauled him away—declined to comment. A CBS News spokesman told me: “This is a legal matter in the hands of the authorities. We have been cooperating and continue to cooperate with the authorities.” (A message left at Halderman’s home was not returned).

Halderman joined CBS News in the early 1980s, after attending college in Arizona, and worked for broadcasts ranging from the CBS Evening News to Early Show, quickly establishing himself as a star field producer who could be depended on to go anyplace and bring back the goods. He won prestigious awards and produced the network’s Olympics coverage and well-regarded reports on Somalia, AIDS, and Chechen rebels, among other subjects. He also was a prodigious reader—usually on planes flying to a far-flung assignment—and colleagues sought him out for book recommendations.

Ironically, given his blackmail threat to Letterman, Halderman carried on extramarital romances both in the office and on the road, colleagues say, and didn’t do much to hide them. He liked to drink, colleagues say, and would occasionally get obstreperous. Once, years ago, Halderman “came stumbling into work in bandages and stitches,” a colleague told me, explaining that a bouncer had shoved him through a plate-glass window at an Upper East Side singles bar.

“He was a very colorful guy—I’d label him a charming rogue,” said a colleague who worked with Halderman off and on over the past 25 years. “He was like a character out of Hemingway, or maybe like The Great Gatsby, without the nuance and mystery…. He was famous for carrying on workplace affairs, bouncing from woman to woman.” After a trip to Moscow, said another colleague, he showed up at a Manhattan party with “a sexy Russian bombshell on his arm."

He had two biological children with his second wife, Patty Montet—whom colleagues say he also met in Russia—and after their 2004 divorce, was ordered to pay nearly $7,000 monthly in alimony and child support. Montet moved to Colorado, and after Halderman’s breakup with Birkitt, his life apparently took a desperate turn.

“His girlfriend dumped him a few weeks ago and his ex-wife took his kids out to Colorado in the last few months,” one of Halderman’s colleagues told me. “He lost his kids, he lost his girlfriend, and maybe he lost his mind.”

Lloyd Grove is editor at large for The Daily Beast. He is also a frequent contributor to New York magazine and was a contributing editor for Condé Nast Portfolio. He wrote a gossip column for the New York Daily News from 2003 to 2006. Prior to that, he wrote the Reliable Source column for the Washington Post, where he spent 23 years covering politics, the media, and other subjects.