In his first month in U.S. custody, the man accused of planning the Sept. 11, 2001, attacks confessed to the crime during questioning and wanted to keep talking about it, according to the psychologist who interrogated him.
But the C.I.A. wanted him to discuss Al Qaeda’s future plans, not the attacks that had horrified America a year and a half earlier, Dr. James E. Mitchell, the psychologist, said. So when the prisoner, Khalid Shaikh Mohammed, mentioned Sept. 11, they would slam him, naked, into a wall.
It was March 2003. That month, interrogators would waterboard Mr. Mohammed 183 times at a secret overseas C.I.A. prison in the mistaken belief, Dr. Mitchell said, that a nuclear attack in the United States was imminent. But Mr. Mohammed still was not saying what his captors wanted to hear.
“We walled him,” Dr. Mitchell said on Monday, explaining that he and his colleagues had rammed their prisoner backward into a wall, to punish him because they feared he was talking about 9/11 to distract them from another looming crime.
The idea that Mr. Mohammed was punished for talking about that topic in his first month of U.S. detention is new to the proceedings. Dr. Mitchell has been testifying in pretrial hearings in the death penalty cases at Guantánamo Bay since 2020 and never mentioned it before.
