Ahilan T. Arulanantham is director of immigrant rights and national security for the ACLU/SC.

I spent the morning of my second full day at Guant'namo observing the military commission hearing of Sudanese national Noor Uthman Muhammed. Muhammed was charged in December 2008 with murder in violation of the laws of war, attacking civilians, and providing material support to terrorism, among other acts allegedly committed between the years 1996 to 2002. A casual observer watching the proceeding could easily have mistaken it for a normal criminal trial. The room itself looks like a fine federal courtroom, with a large jury box (although it has only six seats) and a gallery with seating for about 50 people. The counsel tables are large and equipped with computer screens.

At a superficial level, the conduct of the proceedings also gives the appearance of a high-quality criminal court. The lawyers sound persuasive and well-prepared, as the military judge, Navy Capt. Moira Modzelewski, sits on a high bench in her black robe, listening carefully and asking probing questions.

But a few minutes after we've started, it becomes clear that this is not what American justice typically looks like. The hearing starts 30 minutes late, which is hardly unusual, but it appears the delay has arisen because the defendant has voluntarily chosen to be absent. The rules allow for this, and the attorneys submit a stipulation consenting to it. But we are left to wonder whether this is a form of protest, or instead a decision he made to avoid the lengthy and intrusive protocol that the government has created to transport detainees from their detention camp to the hearing a few miles away.

The main substantive issue on the agenda also appears at first glance to be fairly routine. The defense made a motion asking the court to release funds for a psychiatric expert. The parties argue the motion, debating how to apply a fairly standard body of criminal defense law governing the appointment of psychiatric experts.

But things get interesting when it comes time to explain why the defense needs the expert. The defense is not arguing that Muhammed is insane or mentally incompetent; instead they say they need the psychiatric evidence because he suffers from post-traumatic stress disorder due to his having been subjected to "unique interrogation methods" and "ill treatment" that resulted in extreme "trauma." As a result, they claim, his "post-capture" statements which the government wants to introduce at trial may not be "reliable" or "voluntary."

If it's not clear yet, the defense appears to be talking about torture. As numerous documents uncovered by the ACLU have revealed over the last several years, the government repeatedly tortured detainees held in U.S. custody - in Afghanistan, Guant'namo and elsewhere - in the years following 2002. Muhammed appears to fit the profile, although it's hard to tell because much of the defense's motion on this issue has been blacked out by military censors. Here's an example from the section describing the facts:

Noor has been in the custody of the United States since March 2002. During his detention in [redacted] and Guant'namo he has been subjected to [redacted]. The exact number of interrogations is unknown to the Defense. The interrogation records, especially from [redacted], are woefully deficient...Noor has spent significant time in Camps 5 and 6, under conditions equivalent to [redacted]...Noor's medical records demonstrate a failure of JTF-GITMO [i.e., the military] to treat his chronic medical problems. JTF refused counsel's requests to speak with Noor's medical providers about his chronic pain and treatment. Consistent with JTF policy, the Government has redacted Noor's medical records to conceal the identity of the providers and has steadfastly refused the Defense requests for access to these individuals.

Although we do not get to see for ourselves which interrogation methods he faced, the military defense lawyers say that the government has 17 statements of his that it wants to introduce at trial. Of course, no criminal defense lawyer whose client is going to trial would ever let a defendant talk to the government 17 times, and, one would think, no rational person would submit to 17 interrogations knowing that the statements could be used against him at trial. But this is not rational, it's Guant'namo. Muhammed did not have a lawyer during these interrogations, and he was not given the choice to stop them.

You might also think that the defense does not need a psychiatrist's report to explain why these statements cannot be admitted at trial. In normal criminal court, if the police interrogate someone and refuse to allow the detainee to stop the interrogation once, even without a lawyer present, then the statements obtained from the coercive interrogation cannot be used at trial. If this happens 17 times, there should be absolutely no question that the statements cannot be used.

But this is not ordinary criminal court. Guant'namo has its own rules, recently enacted to comply with the amended Military Commissions Act of 2009 (PDF) but not ratified until the night before the military commissions reconvened under Obama. Buried in Section 949a(b)(3)(B) is a handy little provision stating that "A statement of the accused that is otherwise admissible shall not be excluded from trial by military commission on grounds of alleged coercion or compulsory self-incrimination so long as the evidence complies with the provisions of section 948r." Section 948r, in turn, allows the admission at trial of any statement that is "voluntarily given." You could be forgiven for thinking that any statement obtained by coercion isn't "voluntarily given," but under the Guant'namo rules, you would be wrong. Instead, it is up to the military judge to determine whether a statement is "voluntarily given," and the judge can take into account a number of factors, including "the circumstances of the conduct of military and intelligence operations during hostilities."

It gets better. The defense also says the psychiatric expert's testimony will be relevant to assessing the credibility of statements by other detainees - statements that the government also wants to introduce in this case. At first this confuses me - the statements made during the interrogations of other people are hearsay, so in a normal criminal trial, they would be inadmissible. So why would the defense need to rebut them at trial?

But that basic principle of criminal law is also absent from the Guant'namo rules. Section - take a breath - 949a(b)(3)(D)(ii)(III), is a rule allowing the judge to admit hearsay statements by other detainees if, among other things, the judge determines that "the unique circumstances of military and intelligence operations during hostilities" or the "adverse impacts on military or intelligence operations that would likely result from the production of the witness" justify ignoring the hearsay rule. So the judge may well consider the statements of other detainees obtained using "unique interrogation methods," without allowing the defense a chance to ask those detainees what the soldiers were doing to them when they took the statements.

As the hearing goes on, more and more glimpses into the rules of Guant'namo's netherworld pop up. The military judge makes a passing reference to her ongoing review of documents that are being sent directly from the government to her, without defense counsel seeing them, apparently because they are classified. There appear to be hundreds of these, which she receives in batches of 60'80 documents at a time. While issues involving classified information arise in criminal trials for various reasons, it is fundamental that the government cannot introduce evidence against the defendant without allowing him to see it. But, yet again, that is not how the Guant'namo rules work. Section 949p-6(c) of the Military Commissions Act appears to allow the government to introduce classified evidence against the defendant without letting him see it, as long as the defendant gets a redacted version of the evidence that "is consistent with affording the accused a fair trial."

Shortly afterward the hearing is over, we are left to talk to the reporters - who are just as confused as we are - while the lawyers from both sides scurry off to a closed meeting with the judge. There have been several of these closed meetings in the last few days, which none of us get to see. The escort soldiers are willing to let the reporters talk to us on the sidewalk, but not to let us ride in the same van, although we are going to the same media tent where we can talk to them for as long as we like. This is utterly irrational, but I simply accept it - just another Guant'namo rule.

But in the hours after the hearing, I am more and more troubled as I think about everything that happened. Along with two of the other NGO monitors, I decide to go for a swim to clear my head. We walk down to what seems like the perfect beach - the sand looks lovely, the ocean is bathwater warm, and there's even an iguana strolling by. But as we go in, the sand turns to rock and then to seagrass. I can't wade anymore, so I dive in and open my eyes in the water, straining to see the pretty fish I've been told are here. But the water is murky and opaque, nothing like how it looked from the shore.