WASHINGTON — Senate investigators delivered a damning indictment of CIA practices Tuesday, accusing the spy agency of inflicting pain and suffering on prisoners beyond legal limits and deceiving the nation with narratives of life-saving interrogations unsubstantiated by its own records.

Treatment in secret prisons a decade ago was worse than the government told Congress or the public, the Senate Intelligence Committee’s torture report found. Five hundred pages were released, representing the executive summary and conclusions of a still-classified 6,700-page full investigation.

“Under any common meaning of the term, CIA detainees were tortured,” Sen. Dianne Feinstein, D-Calif., the committee chairman, declared.

 [Read: Senate Intelligence Committee’s full report on the CIA program]

Independent Maine Sen. Angus King released a statement regarding the report. “The study demonstrates that the detention and interrogation program was mismanaged, that some within the leadership of the CIA actively impeded congressional oversight, and that agency officials misrepresented the program’s effectiveness,” according to King’s statement. 

“The Senate Select Committee on Intelligence (SSCI) Review of the Central Intelligence Agency’s (CIA’s) Detention and Interrogation Program devotes much of its report to supporting its judgment that enhanced interrogation techniques (EITs) were ineffective in acquiring intelligence,” wrote Republican Sen. Susan Collins in statement.  “While I agree with the Central Intelligence Agency’s (CIA’s) current position that it is ‘unknowable’ whether or not its ‘enhanced interrogation techniques’ elicited significant intelligence that would not otherwise have been obtained, the fact remains that torture is wrong. “

Tactics included weeks of sleep deprivation, slapping and slamming of detainees against walls, confining them to small boxes, keeping them isolated for prolonged periods and threatening them with death. Three detainees faced the simulated drowning technique known as waterboarding. Many developed psychological problems.

But the “enhanced interrogation techniques” didn’t produce the results that really mattered, the report asserts in its most controversial conclusion. It cites CIA cables, emails and interview transcripts to rebut the central justification for torture — that it thwarted terror plots and saved American lives.

The report, released after months of negotiations with the administration about what should be censored, was issued amid concerns of an anti-American backlash overseas. American embassies and military sites worldwide were taking extra precautions.

Earlier this year, Feinstein accused the CIA of infiltrating Senate computer systems in a dispute over documents as relations between the investigators and the spy agency deteriorated, the issue still sensitive years after President Barack Obama halted the interrogation practices upon taking office.

Former CIA officials disputed the report’s findings. So did Senate Republicans, whose written dissent accuses Democrats of inaccuracies, sloppy analysis and cherry-picking evidence to reach a predetermined conclusion. CIA officials prepared their own response acknowledging serious mistakes, but saying they gained vital intelligence that still guides counterterrorism efforts.

“The program led to the capture of al-Qaida leaders and took them off the battlefield,” said George Tenet, CIA director when the Sept. 11, 2001, attacks occurred. He said it saved “thousands of American lives.”

President George W. Bush approved the program through a covert finding in 2002, but he wasn’t briefed by the CIA about the details until 2006. At that time Bush 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.” Bush said in his 2010 memoirs that he discussed the program with CIA Director George Tenet, but Tenet told the CIA inspector general that never happened.

After al-Qaida operative Abu Zubaydah was arrested in Pakistan, the CIA received permission to use waterboarding, sleep deprivation, close confinement and other techniques. Agency officials added unauthorized methods into the mix, the report says.

At least five men in CIA detention received “rectal rehydration,” a form of feeding through the rectum. The report found no medical necessity for the treatment.

Others received “ice baths” and death threats. At least three in captivity were told their families would suffer, with CIA officers threatening to harm their children, sexually abuse the mother of one man, and cut the throat of another man’s mother.

Zubaydah was held in a secret facility in Thailand, called “detention Site Green” in the report. Early on, with CIA officials believing he had information on an imminent plot, Zubaydah was left isolated for 47 days without questioning, the report says. Later, he was subjected to the panoply of techniques. He later suffered mental problems.

He wasn’t alone. In September 2002, at a facility referred to as COBALT— understood as the CIA’s “Salt Pit” in Afghanistan — detainees were kept isolated and in darkness. Their cells had only a bucket for human waste.

Redha al-Najar, a former Osama bin Laden bodyguard, was the first prisoner there. After a month of sleep deprivation, CIA interrogators found him a “broken man.” But the treatment got worse, with officials lowering food rations, shackling him in the cold and giving him a diaper instead of toilet access.

Gul Rahman, a suspected extremist, received enhanced interrogation there in late 2002, shackled to a wall in his cell and forced to rest on a bare concrete floor in only a sweatshirt. The next day he was dead. A CIA review and autopsy found he died of hypothermia.

Justice Department investigations into that and another death of a CIA detainee resulted in no charges.

During a waterboarding session, Zubaydah became “completely unresponsive with bubbles rising through his open full mouth,” according to internal CIA records.

Khalid Sheikh Mohammed, the 9/11 mastermind, received the waterboarding treatment 183 times. Though officers noted he wasn’t becoming more compliant, they waterboarded him for 10 more days. He was waterboarded for not confirming a “nuclear suitcase” plot the CIA later deemed a scam. Another time, his waterboarding produced a fabricated confession about recruiting black Muslims in Montana.

After reviewing 6 million agency documents, investigators said they could find no example of unique, life-saving intelligence gleaned from coercive techniques — another sweeping conclusion the CIA and Republicans contest.

The report claims to debunk the CIA’s assertion its practices led to bin Laden’s killing. The agency says its interrogation of detainee Ammar al-Baluchi revealed a known courier was taking messages to and from bin Laden.

This story will be updated.

Senate Intelligence Committee Report on CIA Interrogation by PBS NewsHour