A U.S. military jury asked for clemency in the case against a Guantánamo detainee, Majid Shoukat Khan. The jury said in a letter leaked to the media that the detainee’s treatment while in U.S. custody over the past two decades “is a stain on the moral fiber of America.”

The New York Times was first to report and publish the letter.

Majid Shoukat Khan is one of 39 detainees who still remains at the military prison in Guantánamo Bay, Cuba. He was captured in Pakistan in 2003 after he acted as a courier for al-Qaeda. He was held for more than three years at secret CIA prisons known as “black sites.”

The jury heard in graphic detail from Khan himself about the treatment he received. Khan described being held in brutal conditions. He was sleep-deprived, forced to be chained naked, and nearly drowned during waterboarding, according to the leaked letter.