The psychologist who waterboarded a prisoner and created advanced interrogation techniques for the CIA, James E. Mitchell, revealed disturbing details of the prisoner's behavior.

According to Mitchell, the Saudi prisoner, Abd Al-Rahim Nashiri, was so scrawny that Mitchell and his interrogation partner, John Bruce Jessen, stopped waterboarding him after the third session in 2002 at a secret site in Thailand due to concerns about his state.

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In one instance, they tied him to a gurney that acted as a board and put him in a neck brace. However, when they tipped the board up to allow him to breathe after a "40-second pour," the 5-foot-5, 120-pound prisoner nearly slipped out of the straps and onto the floor, according to the psychologist.

Mitchell stated the waterboarding sessions were so long ago that he couldn't remember if the prisoner wept or not.

Nashiri's defense counsel questioned Mitchell on Monday and Tuesday about what happened on the black site in November 2002. His testimony is intended to shed light on what may have been on videotapes destroyed by senior CIA officials during an investigation into black site activity by the Senate Intelligence Committee.

Mitchell portrayed his treatment of the defendant — to prepare him to answer questions under interrogation — as rigorously regulated by CIA physicians and permitted by Justice Department attorneys in his testimony.

Mitchell said he and Dr. Jessen designed a confinement box where the psychologists kept certain captives with the help of CIA officials to replicate one that had been used to educate certain Air Force troops to withstand capture and questioning by the enemy.

According to Mitchell, at first, guards had to order the prisoner into the box, but over time, he began to "like being in the box" and "get in and close it himself."

Like crate-training a dog 

Annie W. Morgan, a former Air Force defense lawyer who serves on Mr. Nashiri’s legal team, stated that she "got the image of crate-training a dog and became nauseous" upon hearing Mitchell talk.

According to Morgan, “That was the goal of the program: to create a sense of learned helplessness and to become completely dependent upon and submissive to his captors.”

Mitchell also detailed some of the mistreatment Nashiri underwent when the psychologist sent the detainee to Afghanistan into the custody of the CIA's lead interrogator at the next black site later in 2002. It was the fourth stop on Nashiri's four-year journey of CIA incarceration via ten secret offshore facilities.

Mitchell described episodes including using a belt to strap Nashiri's arms behind his back and lifting him from behind "to his tiptoes." 

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Guards pushed a chained Mr. Nashiri onto his knees, then bent him backward with a broomstick put behind his knees. The principal interrogator used a sharp bristle brush to give Mr. Nashiri a cold-water wash, then scraped the brush from the prisoner's anus to his face and lips, presumably to instruct him to address him as "sir".

The Senate intelligence report on the program, released in 2014, revealed the practice of having agency medical professionals implant a tube into the rectum of a CIA prisoner who refused to eat or drink and then infusing liquid or puréed food into the detainee. The process has been labeled as rape by prisoners and their attorneys. Majid Khan, a Qaeda courier, said in court last year that the CIA used "green garden hoses" when he was compelled to undergo the treatment.

Mitchell also made a brief reference to the top interrogator probing Nashiri with a power drill and a rifle after he was waterboarded. Mitchell claimed that he did not see the conduct but reported it to CIA headquarters.