The government has argued that the prisoners are among the world's most dangerous terrorists. But as the Guantanamo detainees' cases challenging their imprisonment move forward in federal court, prosecutors have begun dropping some of the central allegations they used to justify locking these men up as enemy combatants.
The reversals have raised questions about whether the government will have enough evidence to convince federal judges to continue to hold the couple hundred men still detained at the Guantanamo Bay prison, defense lawyers say.
"They've been holding these men for more than six years on the basis of these allegations and when a court looks at them they drop them," says Zachary Katznelson, a detainee defense attorney. "It sure looks to any rational observer that they must have something to hide."
In many instances, lawyers say, the government has. The vast majority of the newly filed factual returns explaining the government's central allegations against detainees have been changed and, say defense lawyers, have limited some of the assertions.
The government argues that filing such changes is necessary and that any limitation on changing the allegations "would preclude this Court from considering any wartime intelligence developed by the United States during the past four years," prosecutors wrote in court filings.
Part of the problem is that many of the allegations against detainees may rely on evidence derived from torture or other interrogation techniques that would be questionable in federal court. Others may simply have relied on untrustworthy sources.
Key to the challenge is the government's old process for justifying detention. When the Supreme Court told the government in 2004 that Guantanamo was not entirely immune from court scrutiny, government officials organized what became known as Combatant Status Review Tribunals. But earlier this year the Supreme Court ruled – in a case named for an Algerian detainees captured in Bosnia, Lakhdar Boumediene – that this process was unconstitutional.
"Anyone who has spent any time looking at the CSRT process knows that it was rushed and that it doesn't meet hallmarks of basic fairness," said Vijay Padmanabhan, a former State Department official overseeing Guantanamo issues and now a professor at Cardozo Law School. "So it's not surprising that you're having to see the government come up with narrower cases because they know judges are going to have to look past mere assertions."
Take, for instance, the allegations against six Algerian men -- including Boumediene -- who were captured from Bosnia in 2002.
The U.S. government has claimed that these men planned a terrorist attack on the U.S. embassy in Sarajevo. Though they had been held in Bosnian jail, the country's highest court found there was not sufficient evidence and ordered them released.
The government relied on these claims in court -- through documents called factual returns -- until just a few weeks ago when it a filed a cryptic document noting that it was withdrawing its "reliance on certain assertions in amended factual return."
Lawyers for the detainees say that the filing made clear that the government won't argue that these men were involved in the plot.