A translator for American forces in Iraq pleaded guilty yesterday to possessing secret military documents.

Even as the defendant entered his guilty plea in U.S. District Court in Brooklyn, the question of how he obtained the documents and whether he passed them on to Iraqi insurgents remained unanswered. Other mysteries persist as well, such as the identity of the defendant, who is charged under five aliases and has claimed variously to originate from Morocco, Mauritania, and Lebanon.

In court yesterday, Judge Edward Korman did not ask the defendant for any biographical information beyond his date of birth. The man, 47, initially said he was born in September, but changed his answer to November 11. While defense attorneys and prosecutors conferred with each other, the man, described as a Muslim, fixed a vacant and unblinking stare against the wall.

Although he has not been charged with espionage, prosecutors say phone records and an email account belonging to the man indicate he had ties to Sunni insurgents both while he worked in Iraq as a contracted translator for L-3 Titan Corp., and later upon his return home to Brooklyn.

In court yesterday, when asked by Judge Korman to describe his crime, the man suggested that he had meant to return the documents to the 82nd Airborne.

Three of the four documents have since been declassified. Prosecutors describe the documents as containing a range of information, from descriptions of artillery units to locations which American forces suspected had been used to hide weapons of mass destruction.

After returning to Brooklyn “in haste” following the first of his two stints in Iraq, the man “realized that I had these documents among other documents that I had,” he recounted yesterday.

The man said he didn’t surrender the documents at that point because, when he returned to Iraq, he knew he would be serving with a different unit than he had previously.

“There is no way I could give those documents to another unit,” the man said. “To my knowledge they belonged to the 82nd Airborne.”

He said he intended to “deal with that problem” after the conclusion of this second tour.

The criminal charges against the defendant do not address how he had come to possess the documents, and Judge Korman did not ask about it.

Prosecutors have described the defendant as an Al Qaeda sympathizer who used the security clearance he had as a translator to steal the documents. The four guilty pleas the defendant entered yesterday — one for each document — are admissions only that he knowingly possessed classified documents and that he failed to turn them over to the government.

According to sentencing guidelines, the defendant is likely to get between 11 and 13 years in prison.

An assistant U.S. attorney, John Buretta, told Judge Korman that a fifth classified document, a photograph of an American battle map during the August 2004 battle of Najaf, was also found in the defendant’s possession.