After months of arraignments and preliminary hearings in several cases, the first Guantanamo detainee to actually go on trial pleaded not guilty Monday as his case began in a make-shift courthouse not far from the detention center where he has been held for more than six years. VOA's Al Pessin reports from the Pentagon.

Guantanamo detainee Salim Ahmed Hamdan, far left, sits flanked by his legal team inside the courtroom during a US Military Tribunal arraignment, at Guantanamo (File)

The trial will determine whether Salim Hamdan was just a lowly driver and mechanic, as his lawyers claim, or whether he worked closely with al-Qaida leader Osama bin Laden to plan and carry out terrorist attacks, as the military prosecutors claim. They say he had two surface-to-air missiles in the car he was driving, when he was captured in Afghanistan in November of 2001. Hamdan, who is a Yemeni in his late 30s, faces life in prison if he is convicted.

As the first U.S. war crimes since World War II began, the judge, Navy Captain Keith Allred, threw out some of the evidence against Hamdan, including statements he made while being held in Afghanistan six years ago, during a time his lawyers say he was mistreated. The judge allowed other disputed evidence to be used in the trial. He also instructed the prospective jury members, also U.S. military officers, that they must hear the evidence "impartially" and start with the presumption that Hamdan is innocent - as is the case in all U.S. criminal trials.

Pentagon Spokesman Bryan Whitman called the start of the trial "significant." "It's the beginning of the courtroom processes that will bring illegal combatants to justice for their acts. So it's an important day. But as you know with all these things there have been arraignments, there's been motions. But it is the beginning of the courtroom proceedings and what we call the trial on the merits. So it's a significant day."

The Hamdan trial began in spite of a U.S. Supreme Court ruling last month that detainees at Guantanamo have the right to challenge their detention through U.S. civilian courts. A lower court ruled last week that the military trials can continue while the civilian courts establish a process, and hear and rule on any challenges - a move that angered human rights groups.

Amnesty International called the ruling "a gross failure of the U.S. justice system." At Human Rights Watch, counter-terrorism advisor Stacy Sullivan calls the ruling "a big mistake," and says she does not expect the Military Commissions trials to be fair.

"I don't think there's any question what the outcome of the Military Commissions trials will be. They appear to be rigged from the get-go. There's just so much evidence showing that these are heavily politicized trials that are coming under a lot of pressure from the executive. There are so many things that are unfair toward the accused that there doesn't seem to be any question of what the outcome will be," Sullivan said.

Sullivan notes that one prosecutor resigned, claiming he was being pressured to issue indictments against the detainees, and she says military judges who criticized the process have been reassigned. She also says the all-military process will include unreliable evidence obtained through torture. With regard to Hamdan specifically, Sullivan says he is a "peasant" with a "fourth grade education" who worked as a driver for Osama bin Laden because he needed a job. She says he has cooperated with his American interrogators, and "the notion that he was part of the inner circle" of al-Qaida "seems pretty ridiculous."

Pentagon Spokesman, Bryan Whitman disagrees. "These are people that have conducted unlawful acts for which there is sufficient evidence to try them and hold them accountable for their crimes. There will be a full and fair trial at the military commission proceeding," he said.

A total of 20 of Guantanamo's remaining 265 detainees have been formally charged under the new Military Commissions process created by the Congress last year, after the U.S. Supreme Court struck down the previous process.

Officials say dozens more Guantanamo detainees will be charged, and many others will likely be released. Hundreds have already been released, and dozens of the current detainees have been approved for release, but are awaiting arrangements between the U.S. government and their home countries, or other countries that may agree to accept them.