A U.S. military jury found Osama Bin Laden's former driver guilty of five counts of material support to a terror organization in the September 11, 2001, attacks.
In a split verdict, jurors found Salim Hamdan not guilty of conspiracy to aid a terror organization, in this case al Qaeda.
The trial is being held at the Guantanamo Bay detention facility where he is being held.
Prosecutors allege that Hamdan, who was picked up in November 2001 in Afghanistan, overheard conversations about 9/11 and had other information that showed he was part of Osama bin Laden's inner circle and aided and abetted the attacks.
Hamdan faces life in prison and his lawyers are already planning to appeal.
"Today’s verdict does little if anything to advance American security. The entire process raises fundamental questions about the administration’s disregard for our constitutional values and may well do America more harm than good in the court of world opinion. It took seven years for the Bush administration’s military commissions system to get its first conviction for a crime that is regularly prosecuted in federal court. And when it did, it was a driver who even the administration acknowledges did not participate in the planning or execution of any terrorist attacks. Surely there is a better way to protect America and bring terrorists to justice while adhering to the constitutional values that have kept us safe and strong for 200 years."