The move comes as prosecutors have considered new ways to counter claims by defense lawyers that torture by the C.I.A.
interrogations of Mr. Mohammed and his accused accomplices to produce confessions the government considers its most important trial evidence.
It also shed light on an eavesdropping operation whose existence has until now never been formally acknowledged.
vouched for a transcript of Mr. Mohammed describing how he learned when the hijackers would strike.
Under a classified prison program, more than a dozen suspected terrorists, who had been subjected to years of solitary confinement and tortured by the C.I.A., were granted an hour of recreation time in earshot of another isolated prisoner.
Persons:
Khalid Shaikh Mohammed, Mohammed
Locations:
Iraqi American, Guantánamo, earshot