"In the immediate aftermath of 9/11 we did some things that were wrong. We did a whole lot of things that were right, but we tortured some folks."
It's been more than a year since US President Barack Obama admitted that the CIA tortured prisoners at its interrogation centres.
While the CIA has long admitted the use of waterboarding, which simulates drowning by pouring water into a person's nose and mouth, a truncated and heavily redacted report by the Senate Intelligence Committee in December 2015 detailed other abuses that went beyond previous disclosures.
Reading like a script from a horror film, some of the techniques involved prisoners being slapped and punched while being dragged naked up and down corridors, being kept in isolation in total darkness, subject to constant deafening music, rectal rehydration and being locked in coffin-shaped boxes.