Khalid Sheikh Mohammed
The self-confessed architect of the 9/11 plot, Mohammed was arrested in March 2003 in Pakistan. While he was in CIA custody he was waterboarded 183 times in one month.
In 2008, then CIA director Michael Hayden admitted the waterboarding and told Congress: “there was the belief that additional catastrophic attacks against the homeland were inevitable. And we had limited knowledge about al-Qaida and its workings. Those two realities have changed.”
Held at sites in Poland and Romania while in CIA custody, Mohammed is currently at Guantánamo Bay. He is among five detainees charged by a US military tribunal in relation to the 9/11 plot.
Ammar al-Baluchi
Born Ali Abdul Aziz Ali, he is the nephew of Khalid Sheikh Mohammed. He was arrested in 2003 and held at the “Salt Pit” black site near Kabul, Afghanistan, before being transferred to Guantánamo Bay in 2006.
He is accused of sending money to the 9/11 hijackers and helping them with logistics in the US. “He taught them about everyday aspects of life in the west,” the 9/11 Commission found, “such as purchasing clothes and ordering food.”
Al-Baluchi is believed to have been tortured at a black site.
Abu Zubaydah
A Saudi Arabian who at some point before his capture suffered a form of “cognitive impairment” from a head injury, Zubaydah was arrested in Pakistan in March 2002. He is accused of acting as a senior lieutenant in al-Qaida.
Zubaydah was the first person tortured by the CIA, and waterboarded at least 83 times. He has been held at Guantánamo Bay for more than eight years. The most recent photo of him shows an eye-patch over his left eye, which he was not wearing when he was arrested.
Abd al-Rahim al-Nashiri
A Saudi Arabian charged in a military commission for planning the bombing of the USS Cole in 2000. He spent years in CIA black sites.
The CIA has previously admitted to having waterboarded al-Nashiri. Interrogators also revved a power drill by his temple, fired a pistol near his head, removed his clothing and threatened to sexually assault his mother, according to legal proceedings reported about his case. He is in custody at Guantánamo Bay and has been charged with war crimes.
Abu Faraj al-Libi
A Libyan whose real name is thought to be Mustafa Faraj Muhammad Muhammad Masud al-Jadid al-Uzaybi, he is accused of being an “official messenger” for Osama bin Laden and of orchestrating a 2006 plot to bomb an airplane. Al-Libi was arrested in May 2005 and was one of the last “high value” detainees sent into the black site prison system. He is currently in custody at Guantánamo Bay.
The CIA used “enhanced interrogation” techniques – it’s not clear which – to question him; officials have claimed those interrogations provided clues about bin Laden’s courier system, leading to the raid in which bin Laden was killed.