US Guantanamo Tribunals 'Illegal' - US Supreme Court.
In a landmark decision, justices upheld the challenge by Osama Bin Laden's ex-driver, Salim Ahmed Hamdan, against his trial at Guantanamo Bay.
The court's ruling that the proceedings violated Geneva Conventions is seen as a major blow to the administration.
But the ruling does not mean the closure of the Guantanamo Bay camp.
Mr Hamdan is one of 10 Guantanamo inmates facing a military tribunal.
He is demanding a civilian trial or court martial, where the prosecution would face more obstacles.
The BBC's Nick Miles in Washington says the implications of the ruling are profound, as the tribunals already in place will now be ended and 60 others planned would not go ahead.
The ruling does not demand the release of prisoners held at Guantanamo but gives the administration an opportunity to come up with another way of trying those held.