Secret Case Against Detainee Crumbles

But there was more to the story, as there so often is at the Guantánamo Bay prison in Cuba. Eight months after that newly disclosed assessment of Mr. Gharani was written by military intelligence officials, a federal judge examined the secret evidence. Saying that it was “plagued with internal inconsistencies” and largely based on the word of two other Guantánamo detainees whose reliability was in question, he ruled in January 2009 that Mr. Gharani should be released. The Obama administration sent him to Chad about five months later.

The secret assessment of Mr. Gharani, like many of the detainee dossiers made available to The New York Times and other news organizations, reflected few doubts about the peril he might have posed. He was rated “high risk,” and military officials recommended that he not be freed. But now, a comparison of the assessment’s conclusions with other information provides a case study in the ambiguities that surround many of the men who have passed through the prison at Guantánamo Bay.

The murkiness of the secret intelligence — and the fact that interrogators gathered much of their information from the Guantánamo equivalent of jailhouse informers — has been highlighted in news reports and has drawn criticism from human rights groups in recent days. But some commentators who say the government faced difficulties sorting intelligence in a time of war have noted that such reports were often uncertain, based on bits of information, educated guesses and accounts of witnesses with their own agendas.

“Why is anybody shocked here?” asked James Jay Carafano, a national security expert at the Heritage Foundation in Washington. “The nature of intelligence is it is ambiguous sometimes. It is sometimes based on sources you wouldn’t take to Sunday school.”

Mr. Gharani’s was not the only case to crumble when the Guantánamo intelligence was tested in court. Judges have been unpersuaded by the government’s evidence in several habeas corpus cases, including another federal judge who in 2009 threw out “90 percent” of the case against a young detainee from Afghanistan, Mohammed Jawad, because it was based on a confession he gave that she ruled was “the function of torture.” Mr. Jawad was released soon after.

Mr. Gharani, who was one of Guantánamo’s youngest prisoners, has said he was subjected to abusive treatment at the prison, including solitary confinement and sleep deprivation.

His May 2008 prisoner assessment unambiguously states the most elementary of facts: born in Medina, Saudi Arabia, in 1981.

The document, though, contains few clues that even such statements may be uncertain. In an interview, Mr. Gharani’s lawyer, Clive Stafford Smith, called the quality of the information in the dossier “drivel.” He said Mr. Gharani was six years younger than the military believed. That means he would have been 11, not 17, when he was said to have been linked to a London terrorist cell.

“After seven years of having him in custody,” Mr. Stafford Smith said, “they didn’t even know how old he was.”

The dossier noted that at Guantánamo, Mr. Gharani had confessed to being a member of Al Qaeda and then retracted his admission. “His original admission is assessed to be truthful,” the file said with little explanation.

The strongest statements in the assessment, which was a pattern in many of the files, were attributed to other detainees. In Mr. Gharani’s case, two of those were a Yemeni and a Saudi detainee who provided incriminating information that was quoted in many of the dossiers.

For Mr. Gharani’s file, the two serial informers provided telling details. One, Yasim Muhammed Basardah, said he recalled traveling with Mr. Gharani and other members of Al Qaeda. The other, Abdul Hakim Bukhary, said he had heard that Mr. Gharani was a member of the London terrorist cell and claimed that he “would sing about what he was going to do to the Americans” if he were released.

The assertions from the two men, both since released from Guantánamo, did not note information that might have put their damaging claims in context.

Mr. Basardah, according to other documents reviewed by federal judges in court cases, was an unreliable informer with serious psychiatric problems. The references to Mr. Bukhary did not provide an important caveat: his own dossier said he had acknowledged deliberately misleading interrogators and “has no recollection of a lot of things.”