The interview strategy was good cop, bad cop. Mark Zusman, the editor of the Portland, Ore., alternative newspaper Willamette Week, would lay out a few softball questions for the city's newly inaugurated mayor about the extent of his past relationship with a teenage legislative intern. Zusman would give Sam Adams a chance to cooperate, to come along quietly. If Adams stonewalled, investigative reporter Nigel Jaquiss would move in and lay out his case, compiled over the previous 16 months with the same kind of dogged shoe-leather work that had earned the former Wall Street oil trader a Pulitzer Prize in investigative journalism in 2005.

In the end, Jaquiss told Adams nearly everything he'd dug up over the past year and a half, identifying the sources who'd contradicted the 45-year-old mayor's virulent denials that he'd been anything more than a mentor to the intern. Adams still stood by his story.

The meeting was a disappointment to Jaquiss, who at age 35 had traded in an 11-year career in the marketplace for a reporter's notebook after the death of his parents caused him to re-evaluate his life's purpose. He knew if he went to press with a piece that Adams publicly called false, the reporter would spend weeks fending off critics who'd call him a sensationalistic homophobe, hungry for a repeat performance of the scoop he snared four years earlier when he dug up evidence that former governor Neil Goldschmidt had had a sexual relationship with a 14-year-old babysitter in the 1970s, when Goldschmidt was Portland's mayor.

Jaquiss had already taken heat for the stories he'd written about Adams's relationship with Beau Breedlove, who was 17 when he first met the mayor in the hallway of the state Capitol in 2005. All of the city's local government reporters had covered the allegations against Adams during his 2007 campaign to become the first openly gay mayor of a major U.S. city. But the rest of the press corps mostly stopped chasing the story once Adams went on the attack that September, calling the charges from a would-be opponent in the mayoral race nothing more than a "nasty smear" campaign.

"It plays into the worst deep-seated fears society has about gay men," Adams told Willamette Week's competitor, the Portland Mercury, in 2007. "You can't trust them with your young."

But Jaquiss, who moved to Portland after an unsuccessful attempt at writing a novel about the Russian mob, didn't buy it. Something about the mayor's refusal to discuss certain details of the time he'd spent with Breedlove and the intern's inconsistent descriptions of the relationship aroused his suspicions. He wrote several stories that raised questions about what really happened, drawing fire for a "gay witch hunt," as he puts it, and then quietly kept pursuing the piece, searching out former boyfriends of the mayor and of Breedlove, city staffers, acquaintances—anyone who could help reveal the truth about whether the two were just friends or more than that.

The good cop, bad cop meeting came a few days after a new anonymous tip reached the inboxes of reporters at newspapers throughout the city, one that suggested Breedlove and the mayor had some kind of encounter in a city-hall bathroom and that the mayor's former boyfriend, reachable at an included cell phone number, could provide details.

Jaquiss was worried he'd get scooped on a story he'd been reporting for more than a year, so he and Zusman decided to kick the reporting into high gear, confronting the mayor with what they knew and exposing what they believed was the truth about Adams's public deception and private bad judgment. The mayor's denial in the meeting meant things were about to get ugly, and it meant Jaquiss couldn't be absolutely positive he was about the print the truth. He spent the weekend writing and rewriting, trying to convince Breedlove to go on the record and visiting one of his off-the-record sources to look him squarely in the eye and make sure his portion of the puzzle was as beyond reproach as possible.

By then, reporters at the largest newspaper in the Pacific Northwest, The Oregonian, had begun to circle. On Martin Luther King Day, Jaquiss and Zusman decided, they would publish the allegations on Willamette Week's Web site. Just as they were working on the layout, putting the final touches on the piece, Jaquiss's cell phone rang. It was Mayor Adams, ready to come clean.

The next day, as Barack Obama took his first stab at the oath of office on a frigid day in Washington, a shaken Adams was on his way back to Portland from a lobbying trip to the Capitol, preparing to face a hostile crowd of reporters he'd repeatedly lied to in 2007, to explain that he'd had sex with Breedlove several times beginning a few weeks after the young man's 18th birthday, to apologize, to ask for forgiveness. Calls for Adams's resignation came immediately afterward, from the editorial boards of The Oregonian, The Portland Tribune, The Portland Business Journal and Just Out, the city's oldest gay publication.

Others rallied around the mayor, who had become strangely lionized by the second or third day of the scandal. In the minds of hundreds who commented on newspaper stories and spoke at pro-Adams rallies, Portland would crumble without the leadership of its new mayor. Furthermore, his sex life shouldn't be anyone else's business, they argued. Adams spent the days after the scandal mulling his fate, seeking advice from his friends and colleagues, trying to decide whether his short career as mayor of Portland was over and whether his ambitious 100-day agenda for a city with a nearly double-digit unemployment rate had come to a screeching halt.

Jaquiss's scoop is significant not only because it represents the second huge political figure his journalism has humbled in a period of four years, but also because of whom he beat out to get the story: the much larger and much more heavily financed Oregonian.

Over the years, the daily has earned something of a reputation in Oregon for avoiding sacred cows, after it dropped the ball on two gigantic stories: the sexual abuse and harassment of female staffers and lobbyists by Sen. Bob Packwood in the 1980s, a story The Washington Post broke even after Packwood reportedly harassed one of the Oregonian's own reporters; and the Goldschmidt scandal, which the paper not only failed to pursue but took a beating from the public over after accepting the former governor's confession and using his choice of words—"affair"—to describe what Oregon law considers rape in its front-page headline. (State law defines sexual intercourse with a person under age 16 as third-degree rape, a felony.)

Now the big boys were getting their hats handed to them again. Oregonian metro columnist Anna Griffin wrote an opinion column after the news broke, explaining that she had gotten the tip, and that certain aspects of it seemed plausible, given the mayor's willingness to flirt and his overt sexuality. The mayor took gay members of his campaign team to steam baths during his 2004 run for city council, Griffin added. At the same time, she had a hard time believing it. "Our mayor also has massive ambitions, for himself and his city. Would he throw all that away for a fling?" she wrote. Adams had denied the rumors, and others backed him up: "Casual sex with a barely legal intern? It seemed ridiculous. This is, after all, the most eligible gay bachelor in town we're talking about, handsome and worldly and charming in a brainy, almost goofy way."

The Oregonian printed several stories about the allegations when they were first aired, interviewed Breedlove and checked the mayor's phone records over a six-month period, the newspaper's editor, Sandy Rowe, wrote in an e-mail to NEWSWEEK. Nothing substantial came up, according to Rowe, but Jaquiss got an anonymous tip last April that reinvigorated his work, and by the time the November e-mail about the bathroom incident arrived at several local media outlets, "he knew what he was after and jumped on it." She added, "Nigel has built quite a reputation with sex scandal stories, and deservedly so. He is dogged and very good at that genre."

After Jaquiss won his Pulitzer for the Goldschmidt story, the director of the Project for Excellence in Journalism told the Los Angeles Times that the fact that he'd scooped the major daily in town pointed to the declining investment the mainstream media was willing to make in investigative reporting, leaving it to smaller, independent outlets to dig for the deepest dirt. Tim Gleason, the dean of journalism at University of Oregon, sees the same cutbacks affecting coverage of the Adams scandal: "Larger news organizations are giving up whatever advantage their size and resources once gave them." Of course, the subject matter at hand can also be an issue. Many mainstream news organizations—including NEWSWEEK—have had difficult internal debates about where to draw the lines in covering the private lives of public figures.

But Jaquiss views that as a copout, an overly simple explanation for a problem that is more about one-newspaper towns being a little too cozy with local power brokers.

The Oregonian has acknowledged that the Adams story has presented editors with "tricky questions," as Managing Editor Therese Bottomly put it in a Jan. 26 blog post. Adams's boyfriend, Peter Zuckerman, is a reporter at The Oregonian, and an attorney who sometimes represents the paper has spoken publicly against the press coverage of Adams and has recently taken on Breedlove as a client. The mayor's spokesman, who quit his job without explanation the day Adams returned to Portland, is also a former Oregonian reporter.

"The Oregonian still has a huge stable of talented, great reporters, and they do a lot of really good work," Jaquiss says. "But Portland is a one-party town, a go-along, get-along town where people don't question the orthodoxy. They're very comfortable having a real absence of critical debate of most issues."

In her e-mail, Rowe rejected that statement as a "fact-free blind slam," adding that none of the newspaper's "awkward situations" had influenced its coverage. She pointed to examples of the kind of investigative pieces The Oregonian has published: stories about local citizens' long waits for Social Security disability, about a police chief ignoring tips that one of his officers was involved in dealing and taking steroids and about "how school districts across the state were making secret deals with teachers accused of sex abuse so they could move to a new school and teach again."

The Oregonian's reporters aren't the only ones with ties to the mayor's office. In December 2008, Adams hired Mercury news editor Amy Ruiz to fill a job as his adviser on sustainability and strategic planning, a field in which she seemingly has no experience, unless you count her coverage of city hall. Jaquiss believes that as far as the mayor knew, Ruiz had more information about what really happened between Adams and Breedlove than any other journalist in Portland, which is why Jaquiss highlighted the hire in the piece he wrote for Willamette Week, with a strong insinuation that Ruiz was rewarded with a job she didn't deserve for burying her story. Adams has said that he hired Ruiz because she was "smart" and that it had nothing to do with her past coverage of Breedlove. Ruiz told both Jaquiss's paper and the Portland Mercury that she didn't short-shrift her coverage in the hopes of getting a job with the city, but that she never got enough on Breedlove to publish a story. Neither Adams nor Ruiz responded to repeated requests for comment. (In an interview with Out magazine published Feb. 2, Adams acknowledged that his relationship with Breedlove was "inappropriate," and said that he chose to remain in office because it's "what's best for the city.")

Kelly McBride, a media ethics teacher and consultant for the Florida-based Poynter Institute, a nonprofit organization that examines journalistic standards, posits that the issue may have more to do with the culture at The Oregonian. The paper has built its reputation on thoughtful, narrative coverage, which is a rare and valuable kind of journalism, she says, but it doesn't lend itself well to digging up sex scandals.

"I know from talking to people at The Oregonian that they take very seriously their capacity to break these kinds of stories, and there's a lot of hand-wringing when somebody beats them," McBride says. "But it makes perfect sense to me that they would get scooped, because their culture is so tilted toward the narrative form of storytelling."

In the meantime, the Oregonian has clawed its way back into the story, publishing on its Jan. 25 front page an exclusive interview with Breedlove and photos of the 21-year-old with his newly adopted dog, Lolita. That night, Mayor Adams released a statement that he intended to return to work as the city's mayor, pledging to regain the city's trust, and he went back to work at city hall the next day.

And Jaquiss returned to his tiny cubicle at Willamette Week's Portland headquarters, working the phones amid manila folders and reference books piled high enough to obscure pictures of his family, searching for the answers to lingering questions: What exactly happened between Breedlove and Adams before he was of legal age? How will he be able to govern Portland under the cloud of an investigation from the Oregon attorney general, announced within days of the revelations, and the hit to his credibility?

Despite his Pulitzer pedigree, Jaquiss is more enthusiastic about journalism than arrogant about his accomplishments. What has surprised him the most about becoming a reporter, he says, is how difficult he has found it to determine whether someone is lying to him. After last week, Portland's politicians may think twice about trying to put one over on him.

Editor's Note: This story was updated Tuesday evening, Feb. 3.