This fall, Heebe filed a separate lawsuit against Mann, then the second-ranking prosecutor in Letten’s office. The suit accused her of using an alias to post critical comments about Heebe on the newspaper Web site, in some cases coordinating her comments with Perricone.
Mann also remains under investigation by the Justice Department. Letten said in a recent court filing that Mann admitted writing the critical comments.
A spokesman for the U.S. attorney’s office declined to comment about Mann and referred calls to a spokesman for the Justice Department, who also declined to comment.
Perricone’s attorney, E. John Litchfield, said his client acknowledged the online postings after Heebe’s lawsuit was filed. He said Perricone did not lie or violate any laws.
Because of the online controversy, the U.S. attorney’s office withdrew from the landfill case, which has been taken over by Justice Department lawyers from Washington.
Letten is the second U.S. attorney to resign amid a scandal since President Obama took office. Last year, the U.S. attorney in Arizona resigned in the wake of a botched gun-running investigation.
Federal officials say proving prosecutorial misconduct can be difficult. But papers filed in Heebe’s lawsuit against Perricone indicate that Fitzgerald turned up convincing evidence.
From August 2011 until March 2012, an anonymous blogger posted 598 comments, many of which disparaged Heebe, who was once a candidate to be U.S. attorney.
The blogger called himself “Henry L. Mencken1951.” Among his entries was one that read, “Heebe comes from a long line of corruptors.”
According to court papers, Fitzgerald found “highly distinctive” and “eerily similar” language in the online comments and a nine-page legal pleading co-authored by Perricone. Based on punctuation, alliteration and archaic words such as “dubiety” and “redoubt,” Fitzgerald concluded that a comparison of the two documents “strongly indicates” that Perricone and the commenter were the same person, the lawsuit said.
Fitzgerald declined to discuss the New Orleans case, but in an interview he compared his work to the analysis of DNA.
“Like DNA, language is composed of many small individual parts, letters, syllables, words, phrases and clauses, and it’s how they’re strung together and how they’re punctuated that can be very valuable direct evidence linking one person to one communication,” Fitzgerald said.
The evidence led Perricone to admit that he posted the comments using an online alias that combined the name of the famous Baltimore Sun muckraker H.L. Mencken and the year that Perricone was born, 1951.
Sen. Mary L. Landrieu (D-La.) praised Letten’s long service, but she said that the revelations of prosecutorial wrongdoing were troubling and that the time had come for a change.
“Today’s personnel changes within the U.S. Attorney’s Office for the Eastern District are a necessary step toward public trust in an institution charged with fighting corruption and keeping the people of the Eastern District safe,” Landrieu said in a statement.
Julie Tate contributed to this report.