AFP - An Al-Qaeda sleeper agent who was held in the United States without charge for more than five years as an "enemy combatant," pleaded guilty in a federal court Thursday to supporting terrorism.
"Without a doubt, this case is a grim reminder of the seriousness of the threat we as a nation still face," Attorney General Eric Holder said in a statement.
"But it also reflects what we can achieve when we have faith in our criminal justice system and are unwavering in our commitment to the values upon which the nation was founded and the rule of law."
Ali al-Marri, who was the last remaining "enemy combatant" held on US soil, faces a maximum of 15 years in jail after admitting he conspired to provide material support to Al-Qaeda.
He will be sentenced on July 30. It was not clear how much credit he would be given for time already served.
"He asked for his day in court, and he got his day in court with all the constitutional protections," Marri attorney Jonathan Hafetz told reporters.
"It's all he wanted."
Marri admitted to attending several terrorist training camps in Pakistan from 1998 to 2001, according to a statement of fact in the plea agreement.
He met Khalid Sheikh Mohammed, considered the architect of the terrorist attacks of September 11, 2001, at one of the camps and agreed to go to the United States for an Al-Qaeda operation.
Marri entered the United States on September 10, 2001 with his wife and children, ostensibly to study at an Illinois university.
The next day Al-Qaeda launched its attacks, and Marri continued to work for the terrorist organization by researching poisons such as cyanide and the location of dams, waterways and tunnels.
Marri "researched the use of chemical weapons, potential targets and maximum casualties," said Arthur Cummings, assistant director of the FBI’s National Security Branch.
"The investigation that disrupted his plot began with tips from local police partners," he said, adding that FBI agents traveled "around the globe to develop the intelligence to prevent any potential attack and the evidence to bring al-Marri to justice."
Marri was arrested in Illinois in December 2001 in connection with the terrorist attacks and eventually charged with credit card fraud.
The 43-year-old dual Saudi-Qatari national was declared an enemy combatant in 2003 and spent nearly six years in isolation in a military brig in South Carolina without charge.
His case was transferred to civil court on February 26 when he was formally indicted on charges of providing support to Al-Qaeda and conspiring with others to do the same.
Marri's case raised one of the most vexing questions of the Bush administration: whether a US president has the authority to detain terror suspects -- including legal US residents -- indefinitely without charge.
Unlike the detainees held at the US Naval base in Guantanamo Bay, Cuba, Marri was a legal US resident when he was first arrested.
Marri had pursued a case before the US Supreme Court challenging the president's authority to detain terror suspects indefinitely without charge.
The court had agreed to hear the case, but shortly after the government filed its indictment it urged the Supreme Court to set aside as "moot" the constitutional challenge to Marri's detention as an enemy combatant.
The high court sent the case back to an appeals court, effectively delaying the resolution of an issue that could have implications for the estimated 240 "enemy combatants" still held in Guantanamo.
President Barack Obama has vowed to shut the "war on terror" prison within a year, amid criticism over US interrogation tactics used on some terror suspects, including "waterboarding," or simulated drowning.
However, Defense Secretary Robert Gates on Thursday said that about 50 to 100 of the detainees cannot be tried or released and the government has not yet determined what to do with them.