DETROIT -- Just six days after the World Trade Center crumbled, FBI agents raided an apartment and uncovered what they said was evidence of more plots, helping launch a case that would be hailed as a major victory in the war on terror.
Now, seven months after two Arab immigrants were convicted of being part of a terrorism conspiracy, investigations into the lead prosecutor in the case and the FBI's Detroit offices have intensified doubts that those convictions will hold up.
As US District Judge Gerald Rosen considers whether to grant the defendants a new trial, the Justice Department is investigating new allegations of misconduct by Assistant US Attorney Richard Convertino.
The public disagreement between Convertino and his superiors is highly unusual and could indicate the government is trying to distance itself from the prosecutors, some observers said.
"The Justice Department and the US Attorney's office have sent some pretty strong signals that they're concerned about the behavior of their prosecutors during this trial," said David Moran, a law professor at Wayne State University.
Meanwhile, the agent in charge of the FBI's Detroit field office, Willie Hulon, has been recalled to Washington amid an internal investigation that focuses, in part, on the handling of an informant who says he broke the law while spying on terrorism suspects.
The Detroit case had been touted as an early success in the Bush administration's war on terror. The FBI's raid on an apartment yielded fake documents, airport badges, and a videotape the government said showed possible US targets, including Disneyland and the MGM Grand Hotel and Casino in Las Vegas.
Authorities also found a day planner with what prosecutors said were sketches of an American air base in Turkey and a military hospital in Jordan.
US Attorney General John Ashcroft made such strong statements about the case's significance before the trial ended that he was admonished by the judge for twice violating a gag order.
The probe into Convertino, who was removed from the case in September, is examining whether he withheld evidence from the defense, threatened a defense lawyer with an unfounded criminal investigation, and arranged to reduce the sentence of an illegal immigrant on trial for drug charges in exchange for acting as an informant in the terrorism case.
Convertino refused to comment on the existence of a department investigation but vehemently denied the charges as laid out in the Detroit Free Press, which first reported the investigation this month. He said the leak by Justice Department officials was an attempt to smear him and endangered the life of the drug defendant-turned-informant, Marwan Farhat.
The leak "was meant to deprive me of the opportunity to answer any baseless allegations in the proper form," he said.
A lawyer for Convertino, William Sullivan, said that as a result of the disclosure of informants' names, "one individual was actually shot at." He said that after the incident, which did not result in any injuries, Convertino helped preserve the person's safety.
Sullivan did not specifically name Farhat, but he is the only active informant to be named in media reports and has since left the country.
In a letter written before his departure, obtained by The Detroit News and confirmed to the Associated Press by a federal law enforcement official, Farhat claimed FBI agent Robert Pertuso told him to break the law by stealing mail from people the government identified as terror suspects.
That claim is part of the focus of an internal FBI probe into the Detroit office, law enforcement officials say. The FBI declined to comment.
The US attorney's office and the Justice Department also declined to comment on the Convertino probe or any other aspect of the terrorism case.
Karim Koubriti, 25, and Abdel-Ilah Elmardoudi, 38, were convicted of conspiracy to provide material support for terrorism and to engage in fraud and misuse of visas and other documents. Ahmed Hannan, 35, was convicted of only the fraud charge, and Farouk Ali-Haimoud, 23, was acquitted.
The case has been under increasing scrutiny since December, when Rosen chastised Convertino and his supervisor and cocounsel, Keith Corbett, for failing to turn over evidence that might have helped the defense.
The evidence includes a December 2001 letter from an imprisoned drug gang leader who alleges the government's key witness, Youssef Hmimssa, confided he made up some of his story.