GUANTÁNAMO BAY NAVAL BASE, Cuba — A suburban Baltimore high school graduate turned Al Qaeda courier, speaking to a military jury for the first time, gave a detailed account on Thursday of the brutal forced feedings, crude waterboarding and other physical and sexual abuse he endured during his 2003 to 2006 detention in the C.I.A.’s overseas prison network.
Appearing in open court, Majid Khan, 41, became the first former prisoner of the black sites to openly describe, anywhere, the violent and cruel “enhanced interrogation techniques” that agents used to extract information and confessions from terrorism suspects.
For more than two hours, he spoke about dungeonlike conditions, humiliating stretches of nudity with only a hood on his head, sometimes while his arms were chained in ways that made sleep impossible, and being intentionally nearly drowned in icy cold water in tubs at two sites, once while a C.I.A. interrogator counted down from 10 before water was poured into his nose and mouth.
Soon after his capture in Pakistan in March 2003, Mr. Khan said, he cooperated with his captors, telling them everything he knew, with the hope of release. “Instead, the more I cooperated, the more I was tortured,” he said.
The dramatic accounting capped a day in which eight U.S. military officers were selected to serve on a jury, which will deliberate Friday on his official sentence in the range of 25 to 40 years, starting from his guilty plea in February 2012.
But the sentence is largely symbolic, a military commission requirement.
Unknown to the jurors, Mr. Khan and his lawyers reached a secret deal this year with a senior Pentagon official in which his actual sentence could end as early as February and no later than February 2025 because Mr. Khan had become a government cooperator upon pleading guilty.
Jurors were told that in 2012 Mr. Khan pleaded guilty to terrorism charges, including murder in violation of the law of war, for delivering $50,000 of Al Qaeda money from Pakistan to an Al Qaeda affiliate in early 2003. The money was used in a deadly bombing of a Marriott hotel in August 2003, while Mr. Khan was a prisoner of the C.I.A. He has said he did not know how the money would be used.
He also admitted to plotting a number of other crimes with Khalid Shaikh Mohammed, the accused mastermind of the Sept. 11 attacks, notably by wearing a suicide vest in a failed effort in 2002 to assassinate the president of Pakistan at the time, Pervez Musharraf, a U.S. ally in the war on terrorism.
Sentencing was delayed for nearly a decade to give Mr. Khan time and opportunity to cooperate with federal and military prosecutors, so far behind the scenes, in federal and military terrorism cases. In the intervening years, prosecutors and defense lawyers clashed in court filings over who would be called to testify about Mr. Khan’s abuse in C.I.A. custody, and how.
In court on Thursday, Mr. Khan read from a carefully worded 39-page account that did not identify C.I.A. agents or the countries and foreign intelligence agencies that had a role in his secret detention at black sites — information that is protected at the national security court. He expressed remorse for hurting people through his embrace of radical Islam and Al Qaeda, but also found a way around a labyrinth of U.S. intelligence classifications to realize a decade-long ambition to tell the world what U.S. agents had done to him.
“To those who tortured me, I forgive you,” he said, noting that while he was in custody he had rejected Al Qaeda, terrorism, “violence and hatred.”
“I hope in the day of judgment that Allah will do the same for you and for me. I ask forgiveness from those whom I have wronged and I have hurt.”
It was an emotional day for Mr. Khan. His father, Ali, and a sister, both U.S. citizens, sat behind the court in a gallery, seeing him in person for the first time since he left the United States and joined Al Qaeda after the Sept. 11 attacks. They were 50 feet from him and did not seem to recognize the now balding middle-age man with a gray goatee when he first entered the court.
After many minutes he caught their eyes, then waved. His father looked startled. Mr. Khan craned his neck frequently during the proceedings to see his family — and at one point formed a heart with his hands.
He juxtaposed his remarks of contrition with previously unheard details of what happened to him at the hands of the United States, the country his parents and siblings adopted by becoming citizens even as he did not.
His father wept through long stretches of the descriptions, at times hiding his head in his hands, while his sister, also tearful, tried to comfort him. The jury of Marine, Navy and Army officers watched and listened soberly, but displayed no emotion.
He received beatings while nude and spent long stretches in chains — at times shackled to a wall and crouching “like a dog,” he said, or with his arms extended high above his head and chained to a beam inside his cell. He was kept in darkness and dragged, hooded and shackled, his head slamming into floors, walls and stairs as he was moved between cells.
Before the C.I.A. moved him from one prison to another, he said, a medic inserted an enema and then put him in a diaper held in place by duct tape so he would not need a bathroom break during flights. Guards moving him would hood him, aside from the time he had his face duct taped.
While held in a Muslim country, he said, his captors allowed him to pray. But at times the Americans did not.
Earlier accounts released by his lawyers said he was so sleep deprived for a time that he began to hallucinate. He described the experience: images of a cow and a giant lizard advancing on him inside a cell while he was chained to a beam above his head. He tried to kick them away but lost his balance, causing his chains to jerk him.
Mr. Khan gained attention with the release of a 2014 study of the C.I.A. program by the Senate Intelligence Committee that said, after he refused to eat, his captors “infused” a puree of his lunch through his anus. The C.I.A. called it rectal refeeding. Mr. Khan called it rape.
The C.I.A. pumped water up the rectum of prisoners who would not follow a command to drink. Mr. Khan said this was done to him with “green garden hoses. They connected one end to the faucet, put the other in my rectum and they turned on the water.” He said he lost control of his bowels after those episodes and, to this day, has hemorrhoids.
He spoke about failed and sadistic responses to his hunger strikes and other acts of rebellion. Medics would roughly insert a feeding tube up his nose and down the back of his throat. He would try to bite it off and, in at least one instance, he said, a C.I.A. officer used a plunger to force food inside his stomach, a technique that caused stomach cramps and diarrhea.
The intelligence agency declined Thursday to comment on the descriptions offered in the hearing but noted that the C.I.A.’s detention and interrogation program ended in 2009.
Lawyers sought permission to bring Mr. Khan’s wife and daughter, who was born after his capture, to the court, but the commander of the military’s Southern Command, which oversees prison operations, opposed their attendance. Like Mr. Khan, who acquired permanent resident status as a boy in the United States but never became a U.S. citizen, his wife and daughter are citizens of Pakistan.
Mr. Khan began by telling the jury that he was born in Saudi Arabia and was raised in Pakistan, the youngest son of eight siblings, until his father acquired a gas station in Maryland and moved the family to the United States when he was 16. He went on to graduate from a high school in suburban Baltimore and was working for a telecommunications contractor that managed the Pentagon phone system at the time of the Sept. 11 attacks.
He described the attacks and the death of his mother months earlier in 2001 as a turning point in his life.
Until then, he said, he had straddled two worlds: his traditional Pakistani family life and that of an American teenager who “smoked weed occasionally and had my share of girlfriends,” both of which he hid from his mother. After she died, he said, he was drawn to practicing Islam.
He rejected the explanation that Muslims had carried out the attack, “thinking that this was just another way the universe was kicking me while I was down, making me question my faith in Islam.”
During a family trip to Pakistan in 2002 — in which both he and his sister found spouses in arranged marriages — he encountered relatives, cousins and an uncle who had in earlier years joined the jihad in Afghanistan and had ties to Al Qaeda.
“I was lost and vulnerable, and they went after me,” he said, including by showing him “propaganda videos” about the detention operation at Guantánamo, the base where he would be transferred for trial in 2006.
“I went willingly to Al Qaeda,” he said. “I was stupid, so incredibly stupid. But they promised to relieve my pain and purify my sins. They promised to redeem me, and I believed them.”