A typical New Orleans scandal involving a landfill and federal allegations of bribery completely imploded recently, when a forensic linguist analyzed a series of online comments. The longest-serving U.S. Attorney in the Department of Justice has resigned, and a federal investigator has rushed to Louisiana to investigate a case with a final plot turn worthy of Guy de Maupassant.

The story begins with a prominent New Orleanian named Fred Heebe. And naturally, this being the Big Easy, Heebe has a long relationship with his antagonist in the case, a lawyer named Jim Letten. Both were candidates for the U.S. Attorney appointment for the Eastern District of Louisiana in the earliest months of the Bush Administration. Letten got the job, and had been serving in that post until last Tuesday.

So, in 2001, Heebe went off to make his own fortune. After Hurricane Katrina, Heebe and his company, River Birch Landfill, began to win numerous contracts to handle garbage—suddenly a very lucrative enterprise. One contract in particular seemed to attract the office of the U.S. Attorney, Heebe’s old nemesis Jim Letten. In 2009, River Birch won an exclusive contract with Jefferson Parish for the next twenty-five years. The deal involved a hundred and sixty million dollars, and even a pledge that the Parish would close their own public landfill for the duration of the deal, making River Birch the exclusive provider for the next quarter century.

But soon River Birch’s deals began to look rotten. A state official pled guilty to conspiracy for accepting bribes from an unidentified landfill owner, suspected to be a River Birch executive. More federal indictments came in, including charges of mail fraud and money laundering against Dominick Fazzio, River Birch’s C.F.O. (Fazzio pled not guilty; he will go on trial in April.) Though no charges have been filed against Heebe, and he maintains his innocence, Letten’s investigation into River Birch has continued.

The subject was a popular one in New Orleans and the topic of several online discussions, many of them on nola.com, the Times-Picayune’s Web site. Heebe took notice, especially of two commenters who snarked and ranted with wicked abandon. These two writers, who went by the pseudonymous handles Henry L. Mencken1951 and eweman, pursued Heebe fiercely. In a sixth-month period that ended earlier this year, Mencken1951 alone wrote five hundred and ninety-eight posts, essentially three or four a day.

These posts charged that Heebe “comes from a long line of corruptors,” that his “goose is cooked,” that if he “had one firing synapse” he’d confess, and that if “Heebe doesn’t hear their thundering hoofs galloping” of the arriving posse, then “he’s deaf.” And throughout these screeds, Mencken1951 seemed to know insider information. At one point, he suggested that one of Heebe’s alleged payoffs went to his crony’s “fourth wife’s account.”

Mencken1951 also trashed the other defense attorneys working the case, particularly Buddy Lemann. (We “need to thank Buddy the Lemon for confessing his client is a money launderer.”) Louisiana judges were brutally flamed: “Taxpayers are forced to swill these pigs, they will NOT resign.” One federal judge was condemned as someone who “loves killers.” Another bit of snark goes on about a former governor and the current one: “Stop the Presses!!! Guess with whom Edwin Washington Edwards is going to the BCS game tonight? Yes, his nubile princess—but that’s only part of the story. Guess who go him the FREE tickets? (Theme from Jeopardy)…. Jindal, you’re an @&&!!!”

Pretty quickly, folks at the courthouse realized that these two Internet flamers seemed to know a lot about the case and had uncanny knowledge about how the U.S. Attorney’s office worked. Heebe began to suspect that the authors were probably in that office, using a kind of sock-puppetry to build a better case by destroying Heebe online. So Heebe hired a forensic detective to see if his suspicions were true.

James Fitzgerald is a partner in the forensic firm, Academy Group, Inc., and one of the pioneers of the emerging science now known as forensic linguistics, recently featured in The New Yorker. Fitzgerald was the F.B.I. agent whose work on the Unabomber case was crucial to solving it. He studied some of the linguistic oddities in the Unabomber’s published manifesto and linked them to the works of Ted Kaczynski. Fitzgerald applied similar linguistic analysis in this case.

Taking just the Mencken1951 writings, Fitzgerald noticed that one anonymous posting referred pretentiously to “the daily coils which wrap the common man” and that a court filing signed by several attorneys but ultimately determined to be the writing of Letten’s deputy U.S. Attorney, Sal Perricone, included the sentence “River Birch has coiled Fazzio.” While the use of “coil” to mean “snare” is by no means dispositive, Fitzgerald noted that in a search of more than fifteen thousand cases in Louisiana’s federal courts, he found no use of “coil” with this meaning except in the Perricone filing. Fitzgerald found several nearly unique instances of language usage—a preference for pompous vocabulary such as “dubiety,” “redoubt,” and other ponderous phrasings. The filing included the line “Fazzio’s fate will be decided upon the altar of company loyalty,” and one of Mencken1951’s online flames noted, “He has paid homage at the altar of political corruption.” A search of those fifteen thousand federal court documents turned up only twenty uses of “redoubt,” forty of “dubiety,” and twenty-four of “altar of.” Using these collections of words, Fitzgerald narrowed down the number of suspects to two people—one of them being Robert Browning in his 1869 poem “Dominus Hyacinthus de Archangelis, Pauperum Procurator.” Browning was quickly eliminated from the suspect list, leaving only Sal Perricone. A later study of eweman’s posts uncovered similar unique preferences, among them the use of “fender lizard” as slang for a “cop groupie.”

In the Unabomber case, Fitzgerald pointed out enough similarities of language that it impressed a judge who executed a search warrant of Kaczynski’s Montana cabin. Similarly, in this case, the evidence was strong enough, showing “a high likelihood of common authorship” that Heebe filed a defamation suit, alleging that Mencken1951 was Perricone. Perricone confessed and resigned last March. When further analysis suggested that First Assistant U.S. Attorney Jan Mann was the other anonymous poster, eweman, Heebe brought another defamation lawsuit. Mann also confessed and accepted a demotion in November. On Monday, she announced her retirement.

Heloise-like tip to newbie trolls: don’t create an anonymous handle that includes the year of your own birth (Henry L. Mencken1951) or one that contains a homonym of your own name (eweman).

The general sense in New Orleans was that, with one deputy outed as an online flamer, perhaps Letten could soldier through. But with the recent revelation of Mann’s involvement, Letten fell on his sword and resigned. And now there is a Department of Justice probe with a special investigator looking into Letten’s office, all begun with a handful of nouns and a couple of prepositional phrases. As Mencken1951 noted a little more than a year in a post, “Lawyers make their living by the written and spoken word. Their arsenal is the lexicon and a grasp of how to use the various weapons which lie therein.”

Photograph, of Jim Letten, by Gerald Herbert/AP.