When investigator Nicholas J. Mangieri Jr. was poking around the District government in 1979 on behalf of the U.S. Department of Labor, he came up with what he thought were scandalous revelations. According to several sources, then-Mayor Marion Barry had, as a D.C. councilmember, been trying to use a federal jobs program to garner sexual favors from women—an offense that authorities at the time dubbed “sexual coercion.”

Mangieri had no trouble building a thick docket on Barry. Another federal investigator, Mangieri learned, had been looking into the funds of Pride Inc., an organization founded by Barry and his then-wife Mary Treadwell that had received more than $20 million in federal funds. But that investigator had been told by Mangieri’s boss that any audit of Pride was “off-limits.” The original investigator had obeyed the orders. Mangieri, though, couldn’t let it pass.

As a renegade cop investigating graft and sexual harassment in the District government, Mangieri was a Hollywood cliché, a hack screenwriter’s boilerplate protagonist. He boozed and chased broads, he cared for his two young daughters as a single parent, and, of course, he fought injustice head on. Having served in the Navy during World War II, prospected for diamonds and hunted jaguar in Central and South America, dirtied his hands both as a private dick in New York City and as a chief of police in Alaska, Mangieri thought that he could survive almost anything. It turns out that “anything” didn’t include the pervasive corruption of Washington, D.C., bureaucracies of that era.

Barry’s escapades and the misfortunes of Pride are old news, but they’re all part of Mangieri’s fresh account of big-city sleuthing, titled Broken Badge: The Silencing of a Federal Agent. The book is Mangieri’s attempt to right his reputation and expose the feds’ attempts to protect the city’s four-term mayor before Barry-bashing came into vogue.

As the whole country learned, federal law enforcers in the late ’80s went to great lengths to bust Barry. When Mangieri was investigating him, however, Barry had not gained local fame as a carouser and member of the same drug culture he preached against in public. Nor had the U.S. Attorney’s office begun its grand-jury investigation into Treadwell’s financial shenanigans, which eventually landed her in prison. At least by his account, Mangieri was the first to spot the errant ways of the mayor and his cronies. And for this achievement, he says, he was severely punished.

When Mangieri pressed his superiors to move on the sexual-coercion case against Barry, they told him to back off, according to Broken Badge. He refused.

After numerous confrontations with the stubborn investigator, the powers that be brought up what Mangieri calls “trumped-up charges.” Using an obscure law usually deployed against mobsters or companies trying to steal millions from the government, the feds charged Mangieri with filing false statements on nine loan applications. “He didn’t play the game….He went after them. So they went after him,” says Jim Owens, 75, a former assistant U.S. Attorney who worked with Mangieri at the time.

Mangieri was found guilty of the charges on May 1, 1981, and received a suspended sentence of 16 months. “That was a grave injustice,” Owens says.

The author says the sensitive subject matter of Broken Badge scared off big publishing houses. “No [publisher] would touch it because it’s an exposé,” Mangieri says. A more plausible explanation is that the book is barely readable, packed as it is with memos, legal documents, and more than a few ham-fisted clichés. “I wrote it to re-establish my credibility and to prove my evidence at the time,” says Mangieri of the 411-page book. “I documented everything.”

The ex-agent scraped together $20,000 and in early October published the book himself. Last month, he added a Web site (www.brokenbadge.com). And he started on a C-list media tour, appearing at 6:10 a.m. on Channel 2 in Baltimore, signing books in Fells Point and Williamsburg, and delivering a lecture at Christopher Newport University in Newport News, Va. He’s sold about 200 books so far, he says.

He’ll need a lot of help just to double that figure. For better or for worse, real-life tales of corrupt government agents silencing a Last Honest Man usually don’t read like John Grisham novels. No one shot at Mangieri, kidnapped his daughters, or planted drugs and a dead hooker in his apartment. Instead, the bad guys went after Mangieri in ways that will seem all too familiar to us all: He was discouraged from doing important work, his travel expenses were called into question, he was given a disfavorable performance review, and his response letter to the editor of the Washington Post was never published.

But who was behind it all? The plot of Broken Badge is hobbled by the lack of a clear bad guy. For an investigator, Mangieri comes up short at figuring out who was behind his royal screwing. “Obviously, politically, there was an interest from somewhere in the Carter administration in having him stop his investigation,” says Louis Clark, executive director of the nonpartisan Government Accountability Project, which aids government whistle-blowers and helped Mangieri at the time. “But I don’t know where.” Neither does Mangieri—which damages his credibility as a truth-teller.

While he waits to see if there will be any fallout from his book, Mangieri contemplates how he could have made a bigger impact. “It was worth it, but if I had to do it all over again, I wouldn’t be the only one out there on point,” says Mangieri. “I didn’t realize the government was as corrupt as it was.” CP