"There are other individuals that I may swear charges against, and that's all I can really tell you," Martins said during an Oct. 10 press conference, on the eve of resumed pretrial hearings in the 9/11 case.
The detainees who remain under law-of-war detention are subject to further periodic review, he added. A State Department official made similar remarks when asked how the administration will handle the indefinitely detained prisoners.
"Those that are not currently approved for transfer and are not in military commissions proceedings are eligible to be reviewed by the periodic review board, which will determine whether their continued detention is necessary to protect against a continuing significant threat to the security of the United States," a State Department official said in an email.
Detainees are entitled to a full periodic review every three years, and a file review every six months, which can trigger a full review if it raises a significant question about whether continued detention is warranted. None of the remaining indefinitely detained prisoners are entitled to another full review before President Obama leaves office, and only 11 are entitled to a file review in the next 84 days.
The State Department denied a follow-up request for an interview with someone who could specifically answer questions about what the administration plans to do with the indefinitely detained prisoners.
Guantanamo detainees, and the forever prisoners in particular, are often referred to as the "worst of the worst." But Dixon says the administration could "simply release" some of them.
"I say that because the Periodic Review Board process is fundamentally flawed," he said.
In clearing detainees for transfer, the periodic review board frequently cites a detainee's candor, acknowledgment of past terror-related activities and a renunciation of extremist ideology
Dixon reads this as showing that the board looks for evidence of a "changed mindset," or "whether a detainee admits all of the allegations that are put before them in the periodic review board process."
Though the Pentagon denies this, Dixon said the Catch-22 for detainees undergoing the review process is that the board routinely relies on evidence obtained through torture.
Dixon said that can include evidence federal judges have suppressed in Guantanamo habeas cases.
If you're a Guantanamo detainee, "what do you do," Dixon asked. "Do you admit those allegations to show a 'changed mindset?' Or do you say, 'wait, this is a product of torture, I didn't do these things'?"
Dixon said the Periodic Review Board could interpret it as a lack of candor about prior conduct, concluding that a detainee is still in the fight, when detainees choose not to admit to the allegations against them.
"Like everything else about Guantanamo, it would be hilarious if the consequences weren't so tragic," he added.
The Pentagon's Henderson denied the assertion, saying any material that the Periodic Review Board considers "is screened for information obtained through cruel, inhumane and degrading treatment."
Such information is removed from the compendia before it is presented to the board, Henderson added.
Despite the ban on bringing the remaining detainees to the United States, the Pentagon's Henderson said other options, including prosecution in federal courts, are still being explored.
The Pentagon did not provide further details about that option, but Dixon says it could be viable — particularly for one of his clients, Majid Khan, the only known legal U.S. resident held at Guantanamo.
Pakistan-born Khan pleaded guilty to terrorism-related charges in 2012 but his sentencing has been postponed until 2019. The plea deal requires Khan to testify against self-proclaimed 9/11 mastermind Khalid Sheikh Mohammed in an eventual trial.
Under a provision of the National Defense Authorization Act currently winding its way through Congress, detainees would be allowed to plead guilty in U.S. federal courts by video teleconference, and serve out their sentences in foreign countries.
"Majid would be willing to go that route," Dixon said.
This option not only skirts the congressional ban on bringing detainees to the United States, Dixon noted, it also overcomes the inability to prosecute these men in the military commission system. Anyone willing could plead guilty to providing material support for terrorism, which is not a triable offense by military commission because it is not a war crime, Dixon said.
It is unclear if the administration has made any progress in identifying third countries where detainees who plead guilty could serve out their sentences.
Meantime, prison operations are downsizing along with the detainee population. Last month, commanders shut down operations at Camp 5, a maximum-security lockup with 100 cells. That leaves only two detention-center facilities open, Camps 6 and 7, the latter of which houses the high-value detainees, including Khalid Sheikh Mohammed.
Navy Capt. John Filostrat said the prison staff will shrink by the end of the year, downsizing from roughly 1,900 to 1,500 personnel overseeing detention-center operations.
A lawsuit this week by Miami Herald reporter Carol Rosenberg suggests, however, that prison-staffing levels at Guantanamo are at an all-time high. Rosenberg, who has covered Guantanamo for 15 years, claims that U.S. Southern Command is slow-rolling her request for accurate staffing levels in relation to funding earmarked for expansion projects.
The Pentagon proposed $240 million on building upgrades and new construction in the next five years: $66 million to build a new school, and another $40 million for a new fiber-optic cable that will run from the base to Puerto Rico, Rosenberg's complaint states.
The Pentagon declined to comment on the pending litigation.
Democratic presidential candidate Hillary Clinton has said she supports President Obama's plan to shutter the prison. Republican presidential candidate Donald Trump meanwhile has promised to keep the prison open.
Capt. Filostrat said the joint-task force supports the president's plan to close the detention center, but noted that it will adjust accordingly to a new administration.
When asked if parts of the detention center could be put back into immediate use under a Trump presidency, Filostrat could not say with certainty how many detainees the prison could hold. He did note, however, that it once held about 780 detainees.
A representative for the Joint Task Force Guantanamo for U.S. Southern Command did not respond to several emails seeking comment about the prison's current carrying capacity.
Filostrat meanwhile said Camps 5 and 6 could hold several hundred, while Camp Delta, which includes the first four camps, could theoretically hold more.
"Whatever the order is, we'll carry it out no matter who comes in next," Filostrat said.
"We're planning for every contingency right now," he added. "We'll follow the orders that we get from U.S. Southern Command, and right now we'll take care of the detainees safely and humanely while they're here."
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