The Senate Intelligence Committee has released a blistering, 500-page report on the CIA’s controversial detention and interrogation program, a document that committee chairwoman Dianne Feinstein said represents the most significant oversight effort in the history of the US Senate.

The $40 million, five-year study concluded that CIA officials exaggerated the value of the intelligence they gleaned from dozens of “high-value detainees” held at black site prisons, where they were subjected to so-called “enhanced interrogation techniques” such as sleep deprivation and waterboarding.

The committee reviewed more than 6 million pages of top-secret CIA documents and found that the architect of the interrogation program was a retired Air Force psychologist named James Mitchell, an agency contractor who — according to news reports — personally waterboarded alleged 9/11 mastermind Khalid Sheikh Mohammed. The Senate report does not identify Mitchell by name.

Mitchell has a signed a non-disclosure agreement with the CIA and was unable to discuss his alleged role in the agency's enhanced interrogation program, but VICE News met up with him in suburban Florida to discuss the Senate's report and one of the darkest chapters of the war on terror. This is the first time Mitchell has ever appeared on camera. less