The U.S. Senate Intelligence Committee released Tuesday a roughly 600-page executive summary of its long-awaited 6,000-page report on questionable interrogation methods and torture used by the Central Intelligence Agency in the years following the 9/11 attacks by al Qaeda. The executive summary was led by the committee’s chair, Sen. Diane Feinstein (D-Calif.), and signed by seven other Democrats who sit on the committee, while a separate minority report will be released by the Republicans on the committee, and the CIA is expected to release a response, according to NBC News.

The full summary can be found here. The report was compiled between 2009 and 2013 and cost $50 million. It found that the ramped-up interrogation techniques did not help protect Americans or locate al Qaeda head Osama Bin Laden. Researchers reportedly examined more than 6 million CIA reports over that period, according to the New York Times.

"I can understand the CIA's impulse to consider the use of every possible tool to gather intelligence and remove terrorists from the battlefield, and CIA was encouraged by political leaders and the public to do whatever it could to prevent another attack," Feinstein wrote in the report. "Nevertheless, such pressure, fear, and expectation of further terrorist plots do not justify, temper, or excuse improper actions taken by individuals or organizations in the name of national security."

The CIA reviewed the report in early 2013 and said it contained inaccuracies. CIA leadership has defended its use of what it calls “enhanced interrogation” tactics used on terror suspects following the 9/11 attacks. The former head of the CIA’s Clandestine Services told 60 Minutes in 2012 that everything the CIA did was entirely legal and did in fact save American lives.

“I am very secure in what we did and am very confident that what we did saved American lives,” he said, before describing some techniques, which included waterboarding (which simulates drowning), “stress positions,” depriving suspects of sleep, stripping them nude and slapping them.

He said those methods are made to instill “a sense of hopelessness [and] despair” in the detainee.

Critics call those methods torture. In one case, Khalid Sheikh Mohammed, who is considered the mastermind behind the 9/11 attacks, was water-boarded 183 times and remains in U.S. custody at Guantanamo Bay detention center in Cuba.

In March, Feinstein went public with unprecedented accusations of the CIA of monitoring and attempting to remove key documents contributing to the report from the Senate Intelligence Committee’s network. She also said the CIA was trying to clandestinely discredit her, her colleagues and the report through the media.

Sen. John McCain (R-Ariz.), who was tortured as a prisoner of war during the Vietnam War, has proposed an amendment to the Constitution that would outlaw “cruel, inhuman, or degrading treatment or punishment,” for anyone in the custody of the United States. The U.S. currently outlaws its “torture” under its own definition of any U.S. national or anyone –regardless of nationality- that is located in the United States, per Title 18 in the U.S. Code.