"Under any common meaning of the term, CIA detainees were tortured," Senator Dianne Feinstein, a Democrat and the committee chairman, declared.
Here are six things CBC News has learned about the CIA's detention and interrogation program based on today's report.
The CIA illegally detained a mentally challenged man to force a family member to talk
The Senate committee found that of the CIA's 119 known detainees, at least 26 were "wrongfully held." One of them was an "intellectually challenged" man, Nazir Ali, whose CIA detention and taped crying was used as leverage to get a family member to provide information.
Brutal torture included 'rectal rehydration'
The Senate committee found that at least five detainees were subjected to rectal rehydration or rectal feeding "without documented medical necessity." The chief of interrogations described it as "total control over the detainee." The report also notes "CIA medical officers discussed rectal rehydration as a means of behaviour control" and that a number of other detainees were threatened with the procedure.
The report says allegations that rectal exams were done with excessive force on two detainees at a detention site codenamed COBALT (described by one senior CIA officer as "itself an enhanced interrogation technique") eventually reached CIA leadership. Although a CIA attorney was asked to followup, records don't show any resolution to the inquiry.
"CIA records indicate that one of the detainees, Mustafa al-Hawsawi, was later diagnosed with chronic hemorrhoids, an anal fissure, and symptomatic rectal prolapse," the report reads.
CIA officers with 'histories of violence' participated in torture
Not only did the CIA put people without adequate experience or training in senior detention and interrogation roles, many of them had documented "histories of violence and records of abusive treatment of others." In nearly all of these cases, the report reads, the CIA knew about the officers' violent and abusive behaviour before assigning them to detention and interrogation positions.
President Bush kept in dark for 4 years
Even though then-president George W. Bush had approved the secretive CIA program in 2002, he wasn't informed about the gruesome details until April 2006 — four years later. No CIA officer, up to and including directors George Tenet and Porter Goss, briefed Bush on specific enhanced interrogation techniques. The report notes that by the time he was told, 38 out of 39 identified detainees were already being subjected to those techniques. Bush and former vice-president Dick Cheney were also not told the locations of all detention facilities.
"According to CIA records, when briefed in April 2006, the president expressed discomfort with the 'image of a detainee, chained to the ceiling, clothed in a diaper, and forced to go to the bathroom on himself,'" the report reads.
Outside contractors helped with CIA's dirty work
There's a reasonable expectation that if you hire someone for a job, they have the knowledge and skills to carry out that job.
The CIA hired two psychologists, James Mitchell and Bruce Jessen, to develop enhanced interrogation techniques to be used on terror suspects and other detainees. The pair did not have any experience as interrogators, specialized knowledge of al-Qaeda, backgrounds in counterterrorism, or any relevant cultural or linguistic expertise. Their prior experience was at the U.S. Air Force survival, evasion, resistance and escape school, according to the report.
Despite that, the psychologists "carried out inherently governmental functions," including personally using techniques they designed on "some of the CIA's most significant detainees." The psychologists then formed a company specifically to work with the CIA.
By 2008, the CIA's Rendition, Detention, and Interrogation Group (the lead unit for detention and interrogation operations) outsourced 85 per cent of its workforce to that company. The contractors were paid more than $80 million, along with an extra $1 million to protect the contractors from "legal liability arising out of the program."
CIA officers, contractors rarely held accountable, even when detainees died
The committee report reveals that even after "significant events" of wrongdoing, including the death and injury of detainees, CIA officers and contractors were rarely held accountable or removed from positions of responsibility. In one such instance, after a detainee died at COBALT, CIA headquarters decided not to take any disciplinary action against an officer because they were "motivated to extract any and all operational information" from the detainee.
The CIA also let slide a wrongful detention because, "The director strongly believes that mistakes should be expected in a business filled with uncertainty."