GUANTANAMO BAY, Aug. 30 -- FBI agent Frank Pellegrino sat down with Khalid Sheikh Mohammed at the American naval base in Cuba in January 2007 believing he had been given a straightforward task: interview a man who had already told the CIA everything he knew, through methods that would not pass legal scrutiny, and try again the right way. He read Mohammed his Miranda rights. He conducted the session without threats. "I couldn't have told him in any more explicit a way that he did not have to talk to me," Pellegrino said later under oath.

A military judge has ruled that none of it was enough.

Lt. Col. Michael Schrama suppressed the confession on Friday, finding that the CIA's years of psychological conditioning and coercion had been so th...