A Nov. 21 article about investigative reporters misstated the chronology of a lawsuit involving April Oliver, a former CNN producer, and one of her sources, Maj. Gen. John Singlaub. Singlaub first sued CNN and Oliver. Oliver then countersued Singlaub and also filed a claim against CNN. (Published 12/2/2005)

Investigative reporters are, by their nature, dogged, tenacious and deeply suspicious, crashing through official roadblocks as they chase the most elusive stories.

Some of them continue that quest long after their support evaporates, their evidence crumbles and even their employers abandon them.

Mary Mapes, the CBS producer fired over the journalistic fiasco involving President Bush's National Guard service, is the latest in a line of lonely crusaders, defending her work more than a year after it was widely discredited. Dan Rather may have apologized for the story, an independent panel may have denounced it, and CBS News may have criticized her "disregard for journalistic standards," but Mapes argues in her new book that the critics are politically motivated, cowardly or just plain wrong.

In challenging those who have questioned her work -- including The Washington Post and this reporter, who is cited in the book for a triple-bylined news story recounting the mess -- Mapes displays the relentless qualities that all good diggers share. But she also opens herself up to the charge that her obsession has clouded her judgment.

Mapes is right that the purported 30-year-old memos by Bush's long-dead squadron commander have not been proved to be forgeries, but is that the standard for broadcasting a serious charge? The documents have not been proved to be real, either, and endless debates about superscript and proportional spacing are not likely to change that.

In the same week that Mapes's "Truth and Duty" was published, Judith Miller was forced out of the New York Times after years of controversy. Miller, too, had lost the support of her news organization -- her executive editor, while praising her past contributions, had accused her of misleading the paper in the Valerie Plame leak investigation -- and her take-no-prisoners style had alienated many of her colleagues.

Unlike Mapes, Miller finally acknowledged, more than a year after the fact, that her stories on Iraq and weapons of mass destruction had been wrong. But she expressed no regrets about this, saying matter-of-factly, "If your sources are wrong, you are wrong." There was "lingering fury" toward her, Miller told CNN's Larry King, because some of her stories "had turned out to be based on faulty intelligence."

Not that Miller was a passive conduit. When the Army unit with which she was embedded in 2003 was ordered to pull back from its search for illegal weapons, Miller wrote military officials: "I intend to write about this decision in the NY Times to send a successful team back home just as progress on WMD is being made." The order was later rescinded.

Miller deserves credit for her willingness to go to jail rather than testify about her conversations with I. Lewis "Scooter" Libby. Yet she continues to defend her decision to leave jail 85 days later and testify, despite criticism that this undercut her original stance. She has accused editors at the Times of "unsubstantiated innuendo" and "ugly" and "inaccurate" criticism -- a turbulent end to a career in which she was part of a Pulitzer Prize-winning team.

April Oliver, a former CNN producer, also wound up at war with her ex-bosses. She sued the network in 1999 over its retraction of her story alleging that U.S. soldiers used lethal nerve gas in Laos during the Vietnam War. Oliver and a second producer were fired, and correspondent Peter Arnett was reprimanded, when CNN and Time apologized for the "Operation Tailwind" story.

Just as Mapes has denounced the independent CBS inquiry co-chaired by former attorney general Richard Thornburgh, Oliver assailed CNN's outside investigation, headed by attorney Floyd Abrams, as a whitewash. One of Oliver's sources, retired Adm. Thomas Moorer, later denied the story. Oliver wound up suing another of her sources, retired Maj. Gen. John Singlaub, who in turn sued her and the news outlets. Oliver, who eventually settled her suit against CNN, told The Washington Post Magazine that the military had "gotten to" some of her sources.

Perhaps the saddest case involved Gary Webb, a San Jose Mercury News reporter who suggested in a 1996 series that the CIA knew a drug ring linked to the Nicaraguan contras had been selling crack in Los Angeles. When the "Dark Alliance" series caused an uproar, the Mercury News editor concluded after a review (and critical pieces in other major newspapers) that it "fell short" of the paper's standards. Webb, who called the findings "bizarre" and "nauseating," left the paper after being demoted. He committed suicide last year.

Not all investigative reporters stand by discredited stories. While researching a 1997 book on JFK, Seymour Hersh was taken in by Lawrence Cusack III, who was peddling what turned out to be fake Kennedy documents. But Hersh concluded that he'd been had, deleted the material from "The Dark Side of Camelot" before publication and helped expose Cusack, who was convicted of fraud.

Mapes, however, did not lose faith in her story even after her key source, former National Guardsman Bill Burkett, admitted lying to her about where he obtained the disputed documents. Nor was she swayed by criticism from some of the document experts hired by CBS to vet the papers (one of whom, Emily Will, recently set up a Web site to denounce Mapes's book).

Instead, Mapes continues to argue that the "60 Minutes II" segment was "well researched and well documented" and that CBS and its corporate parent, Viacom, caved to pressure by abandoning her and the story.

"What CBS News did was choose to handle this in the most divisive way possible by launching an investigation that forced people to turn against each other, by questioning its employees, and by believing conservative bloggers instead of people who worked for them for decades," Mapes told CNN.

Actually, what CBS did was try to salvage its reputation by asking outsiders to evaluate a story that its news division could no longer defend.

Without the determination of investigative journalists to ignore outside pressure while turning over every possible rock, some important secrets would never be uncovered. But sometimes the reporters never hit pay dirt and just dig themselves into a deeper hole.

Footnote: The controversy surrounding Bob Woodward involves not an inaccurate story but the holding back of information. Woodward, the Washington Post sleuth who apologized last week for not telling his bosses that a senior administration official had discussed Plame with him in 2003, has drawn criticism from some colleagues over his unique role in which he basically writes books while remaining on the Post payroll. He gave his detractors ammunition by commenting on the case while keeping quiet about his involvement. Those who say that Woodward's extraordinary access to top administration officials has made him too much of an insider have a point, but they forget that his books invariably produce news, often about conflicts among those officials.

Plagiarism Watch

Ken Parish Perkins, television critic for the Fort Worth Star-Telegram, resigned last week after being confronted with several instances of apparent plagiarism.

After a caller noted that Perkins had used a paragraph as it appeared verbatim in Entertainment Weekly, editors found several pieces in which he had lifted long phrases or sentences without attribution. Perkins was such a hard worker that "it's so hard for us to understand why this happened," Editor Jim Witt was quoted as saying.

Meanwhile, the Bakersfield Californian found that more than a third of the 96 stories written by Nada Behziz contained "plagiarized material, misattributed quotes and information, factual errors or people whose existence could not be verified -- including seven physicians and a UCLA professor." Behziz, who was fired last month, told the paper: "This is a witch hunt. Too bad your news organization is not this vigilant in pursuing true wrongdoers."

Howard Kurtz hosts CNN's weekly media program.

Seymour Hersh admitted to being duped.Mary Mapes stands by her story regarding the Bush Guard papers.Judith Miller spent 85 days in jail rather than testify about the CIA leak story.Gary Webb killed himself after being demoted for his series on CIA involvement in the drug trade.