It's not every day a presidential news conference is interrupted for a Marin County resident with a few thoughts to share.

But John O'Connor is no ordinary local, and his story is no ordinary story.

O'Connor, the Kentfield attorney who recently unmasked the Watergate tipster known as Deep Throat, has spent a whirlwind two weeks fielding questions from the likes of Katie Couric, Ted Koppel, Harry Smith and Charles Gibson.

One network even ran the audio of an O'Connor interview over live television coverage of a press conference with President Bush.

"It was a very weird experience," O'Connor said during a phone interview from New York.

O'Connor has had many unusual experiences since May 31, when Vanity Fair magazine published his piece identifying retired FBI supervisor W. Mark Felt, a 91-year-old Santa Rosa resident, as the notorious Watergate informant. It was Felt's clandestine meetings with Washington Post reporter Bob Woodward that kept the Watergate story alive and led to the resignation of President Nixon in 1974.

"I think what Mark Felt did for society was he helped enshrine the values of transparency and openness and honesty," O'Connor said. "Today, it's accepted by all that if your boss asks you to do something that's illegal, you shouldn't have to do it, and you shouldn't have to lose your job."

O'Connor's role in bringing Felt's secret to the world began with a chance encounter in 2002, O'Connor wrote in Vanity Fair. O'Connor's daughter, Christy, then a junior at Stanford, invited several college friends to dinner one night, including Nick Jones.

During dinner conversation, O'Connor happened to tell an anecdote about his father, a lawyer who had worked as an undercover FBI agent during World War II. Jones mentioned that his grandfather, like O'Connor's father, was also a lawyer and an FBI agent.

"You may have heard of him," Jones said. "He was a pretty senior guy in the FBI É Mark Felt."

O'Connor, a longtime Watergate buff, knew who Mark Felt was. Felt, a former prot}g} and top assistant to longtime FBI Director J. Edgar Hoover, was believed by some Watergate aficionados to be Deep Throat.

"You're kidding me," O'Connor told Jones. "Your granddad is Deep Throat! Did you know that?"

O'Connor, in the magazine piece, recalled that Jones responded somewhat tentatively. "You know, Big John, I've heard that for a long time," Jones said. "Just recently we've started to think maybe it's him."

Felt had long denied being Deep Throat and was living in quiet retirement with his daughter, Joan. But he had suffered a stroke in 2001 and was showing signs of old age, and his family was concerned he might die before being able to enjoy public recognition for his role in Watergate.

Joan Felt has also said the disclosure, if conducted on Felt's terms, might create financial opportunities that could help pay the education bills for Felt's grandchildren.

Felt's family had initially discussed some kind of collaborative disclosure with Woodward, who had promised to preserve Felt's secret until his source died. But the idea fizzled, so the family enlisted O'Connor as a lawyer/ writer/spokesman who could develop the story, protect it and guide it to the right venue.

"It was not hard to get the attention of someone about this particular matter," O'Connor said. "What was difficult was getting them to accept that this was absolutely certain. And I understand. People with integrity don't want to come out with a story that might be false."

O'Connor approached numerous publishing outlets, which he declined to identify, before settling on Vanity Fair. Only three people at the magazine knew about the story - top editor Graydon Carter, subeditor David Friend, and the magazine's attorney - and all signed confidentiality agreements, according to Friend.

"It was a dance between us and O'Connor and the family," Friend said. "I think they looked at it as an insurance policy. If the story came out, they would have celebrated his life while he was alive. If they waited to do a book first, it's a much longer process, and who knows whether it might have survived.

"I think they felt we were honorable people and we would do the story justice."

Friends of O'Connor said he was an excellent choice to manage the story - a lawyer with a zeal for investigation, a good writer, and a down-to-earth person with a sense of decency.

"He's a fine attorney and he's actually a lovable individual," said Joe Escher, a partner at O'Connor's San Francisco law firm, Howard Rice Nemerovski Canady Falk and Rabkin. "He's extremely funny, a great raconteur, a real character.

"It's been very amusing, and it's kind of exciting. I'm kind of happy for John that he's getting so much positive attention. It's exciting to get the attention."

U.S. Rep. Dan Lungren, who went to school with O'Connor at Notre Dame, said O'Connor has a "bumbler" courtroom persona that masks a sharp intellect and a photographic memory.

"John's a guy you'd like to watch a ballgame with," said Lungren, R-Sacramento, a former California attorney general. "John's a guy you'd like to have a barbecue with. É He's just a well-rounded guy. The only thing he can't do is ride a horse."

O'Connor, 58, has lived in Marin since 1978, first in San Anselmo and then in Kentfield. He and his wife Jan have three children, John, a 26-year-old investment associate at Stanford University; Christy, a 24-year-old law student at the University of California, Los Angeles; and Carly, a 22-year-old student and soccer player at Duke University.

An Indianapolis native, O'Connor earned an undergraduate degree in political science at Notre Dame and a law degree at the University of Michigan. The former federal prosecutor specializes in product liability and other business-related litigation, and his clients have included Lungren, former Golden State Warriors coach Don Nelson and the R.J. Reynolds Tobacco Co.

O'Connor, a former Democrat who became a Republican during the Reagan years, considers himself a political centrist. He voted for Hubert Humphrey in 1968, but Richard Nixon in 1972.

"My beliefs are not that much different from those held by John F. Kennedy, who was one of my heroes," he said. "But I think the party, especially in California, has moved too far beyond that. I'm a moderate person by nature. If I lived in Indiana, I might still be a Democrat."

Despite his stunning scoop for Vanity Fair, O'Connor said he has no plans for a new career as a journalist, and he looks forward to returning to his law practice when the limelight fades.

"I've had 13 and a half minutes of fame and maybe I've got a minute and a half left," he said. "As my father would say, it'll be something for my obituary."