In late 2002, the CIA asked the Federal Bureau of Prisons (BOP) to send a training team to a CIA black site in Northern Kabul, Afghanistan, code-named COBALT. While there, the BOP team instructed guards on the proper use of a restraining technique against detainees called "short chaining," also referred to as short shackling.

Not long after the BOP team left the black site, the technique was used on an Afghan militant and suspected al-Qaeda operative named Gul Rahman, who had been captured by the Pakistani government during a raid a month earlier. Deemed a high-value detainee, he was then taken to COBALT. While being held captive at the black site, the CIA said Rahman became violent, and on numerous occasions had threatened to kill guards.

On November 19, 2002, at about 3pm, guards brought food to Rahman's cell. The last meal he'd eaten had been the day before. When the guards entered Rahman's cell, he was nude from the waist down. The captive again threatened to kill the guards and proceeded to throw his food, water bottle, and waste bucket at them.

The guards, acting on BOP recommendations, shackled Rahman to the wall "in a short chain position, which prevents prisoners from standing upright." Rahman was chained to a "metal grill located low on the wall of his cell" on orders from the CIA officer who managed the black site.

The next morning, at about 10am, Rahman was seen lying on his side. The guards tried to rouse Rahman by banging on his cell door with their nightsticks. But he didn't move. The guards then "notified several CIA officers who were present at the facility in conjunction with the interrogation of another prisoner."

When the officers entered Rahman's cell they saw "a small amount of blood coming from his nose and mouth." A CIA officer checked Rahman's pulse. There was none. They unsuccessfully tried to resuscitate the detainee before he was pronounced dead.

Rahman, according to an autopsy performed by a CIA pathologist, "likely" froze to death.

That's the narrative contained in several internal CIA reports prepared by the agency's inspector general and directorate of operations, along with a special accountability board that spent three years probing Rahman's notorious death at the infamous black site also known as the Salt Pit.

The CIA's reports about Rahman's death have been shrouded in secrecy for 13 years. But VICE News obtained heavily redacted copies of documents describing the findings of those reports, which were shared with a handful of members of congressional oversight committees in 2002, 2003, and 2006, in response to a Freedom of Information Act (FOIA) lawsuit. The declassified documents contain new details about Rahman's death, the CIA's failure to hold anyone accountable for it, and the agency's briefings to a handful of lawmakers. The disclosures make clear that congressional committee leaders on both sides of the aisle were aware as early as January 2003 that the CIA operated an abusive interrogation program that resulted in the death of a detainee, and that the agency ran black site facilities where captives were held incommunicado.

Before Rahman died, retired Air Force psychologist Dr. Bruce Jessen, who was under contract to the CIA and is credited as being one of the architects of the CIA's torture program, was asked to travel to the Salt Pit to perform a psychological evaluation on Rahman and decide which torture techniques should be used on him. Jessen, who left the site a few days before Rahman died, participated in some of Rahman's interrogation sessions, conducted by the manager of the black site, a junior CIA officer named Matthew Zirbel.

"As reported to CIA Headquarters, this interrogation included '48 hours of sleep deprivation, auditory overload, total darkness, isolation, a cold shower, and rough treatment,'" according to a blistering December 2014 Senate Intelligence Committee report that probed the efficacy of the CIA's torture program. "CIA Headquarters did not approve these interrogation techniques in advance."

Jessen and James Mitchell, the other retired Air Force psychologist under contract to the CIA who helped design the agency's torture program, are now defendants in a civil lawsuit filed against them by Rahman's family and two detainees — Suleiman Abdullah Salim and Mohamed Ben Soud — who survived their captivity and torture. The lawsuit filed in federal court in Spokane, Washington last October by the ACLU accused Jessen and Mitchell of war crimes and nonconsensual human experimentation and torture.

Neither Jessen nor Zirbel could be reached for comment.

Dror Ladin, an ACLU attorney who represents Rahman's family and the two other torture victims, told VICE News details contained in some of the documents about Rahman's death are "chilling" and underscore "the general disarray of the torture program."

"The systematic brutality of the CIA's interrogation and detention program comes through in every detail," Ladin said. "The documents also demonstrate the complete impunity with which the CIA's torture program proceeded: Even when Gul died as a result of torture, and even when the CIA's Special Accountability Board found that discipline was merited, ultimately no one was held accountable."

The fact that BOP personnel were present at the black site and instructed guards on how to use the shackling technique is one of the more noteworthy revelations contained in the nearly 100 pages of CIA documents. The CIA's investigations attempt to shift some of the blame for Rahman's death onto the BOP and the practice of shackling.

The Senate's torture report contains a section about Rahman's notorious death. The report noted that a delegation of BOP personnel conducted an assessment of COBALT and the CIA's operations there, which they characterized as disastrous, but the report did not state that BOP personnel also provided training to interrogators and guards on specific interrogation techniques.

"Following the November [redacted], 2002, through November [redacted] 2002, visit, CIA officers in [Afghanistan] remarked that the Federal Bureau of Prisons assessments, along with recommendations and training, had 'made a noticeable improvement on how the day to day operations at the facility are performed,' and made the detention site a 'more secure and safer working environment for officers,'" the Senate report said.

A BOP spokesperson did not respond to VICE News' requests for comment about the report on Rahman's death. After the Senate report was released, VICE News filed FOIA requests with the BOP seeking documents pertaining to the presence of BOP personnel at COBALT and other black sites. The BOP responded by saying it could not locate any records.

It's not the first time the US government adapted BOP methods for use against detainees. At Guantanamo, the military says the force-feeding procedures to which hunger-striking detainees are subjected were based on BOP guidelines.

In a statement provided to VICE News, Senator Dianne Feinstein, the Democratic co-chair of the Senate Intelligence Committee who spearheaded the investigation into the CIA's torture program, said that while there is "broad agreement" that the CIA's torture program was a "mistake," many of the "systematic problems and specific abuses have received very little public scrutiny." Feinstein singled out Rahman's death and the lack of accountability as one example.

"The CIA's internal documents on the death of Rahman highlight how many of the specific problems associated with the detention and interrogation program have still not been made public," Feinstein said. "The release of these documents also shows how important it is to preserve and disseminate the Intelligence Committee's full report so that appropriately cleared officials can learn from the mistakes of the past. Only if we learn from our past mistakes can we ensure that they're never repeated in the future."

The CIA's directorate of operations investigation into Rahman's death, which was shared with just a handful of congressional oversight committee members in May 2003, said guards at the black site checked on the detainee at 10pm and 11pm, and again at 4am and 8am.

"They found him alive and seated upright," the CIA's investigation found. "Guards noted that he was shivering; however, they noted that all prisoners frequently shiver."

On the night Rahman died, the outside temperature was 31 degrees Fahrenheit. The black site was not insulated.

An autopsy conducted on Rahman by a CIA pathologist listed his cause of death as "undetermined" but "indicated hypothermia, by a diagnosis of exclusion." The autopsy said Rahman had "several surface abrasions" on his body "which he obtained within the first few days of his incarceration." The Senate report said Rahman was dragged through the dirt after being beaten during an interrogation session.

"These abrasions were caused by rough treatment designed to frighten and disorient the prisoner. Additionally, the autopsy found no evidence that Rahman had been beaten, tortured, poisoned, strangled, or smothered," said the CIA investigation into Rahman's death conducted by the directorate of operations.

The CIA pathologist concluded that hypothermia was the likely cause of death based on the following factors: Rahman's urine had high catcholemine levels, consistent in hypothermic deaths; he was seen "shivering for a number of hours immediately prior to his death"; "the environment in which he was housed was extremely cold"; he was dehydrated, a contributing factor to hypothermia; he hadn't eaten for 36 hours; he was naked from the waist down and was "in direct contact with the concrete floor of his cell. Direct conduction would have caused significant heat loss in the body."

The CIA's counterterrorist center, which managed the torture program, recommended "improvements" to detainee "management and welfare practices" after Rahman's death. The "most important," according to the directorate of operations investigation, "was to ensure temperatures inside the [black site] are monitored and kept within a range that would not cause health risks to the detainees."

Stanley Moskowitz, the CIA's director of congressional affairs, notified seven Democratic and Republican lawmakers, members of House and Senate oversight committees who were read into the torture program, about Rahman's death on November 29, 2002, nine days after he died. Moskowitz's letter said that Rahman was an associate of Afghan warlord Gulbuddin Hekmatyar, a designated global terrorist, and his Hezb-e Islami Gulbuddin (HIG) insurgent group; had close ties tosenior al-Qaeda facilitator Abu Abdul Rahman al-Najdi, and that ever since Rahman was detained at COBALT, he had been "consistently uncooperative and displayed evidence of a high level of training on resistance to interrogation techniques."

"While consistently calm and controlled during interaction with CIA officers, Rahman reportedly was extremely hostile [redacted] guards at the facility and had directly threatened [redacted, believed to be US military] guards during the week" leading up to his death.

(The ACLU maintains that Rahman fled Afghanistan after the US invaded in 2001 and settled in Pakistan with his wife and four daughters at the Shamshatoo refugee camp outside of Peshawar, earning a living by selling wood to other Shamshatoo camp refugees.)

Moskowitz said the CIA was sending a team of officers to the black site to "conduct an inquiry" into Rahman's death and an autopsy to determine the cause. The Senate's torture report said Zirbel's cable sent back to CIA headquarters about Rahman's death contained numerous "misstatements and omissions."

After the CIA's directorate of operations probed Rahman's death, the agency's inspector general was asked to look into it. On January 23, 2003, CIA Inspector General John Helgerson sent a letter to George Tenet, the director of the CIA. Helgerson said he learned from the deputy director of operations two days earlier "of what may have been unauthorized, inappropriately intimidating treatment by Agency officers of a suspected terrorist being held for questioning at an overseas facility."

That incident involved a 60-year-old interrogator identified as "Albert" in a September 7, 2010 Associated Press report. Albert, a former FBI agent of Egyptian descent who worked as a translator for the bureau prior to his stint with the CIA, wanted a detainee to believe he was going to die. So he revved an electric power drill and waved a handgun at the head of Abd al-Rahim al-Nashiri, the accused mastermind of the October 2000 bombing of the USS Cole in Yemen, while he interrogated him at a black site in Poland in December 2002. Al-Nashiri is currently facing a war crimes tribunal at Guantanamo.

Separately, "the General Counsel on 22 January [2003] informed me of his understanding that an individual who recently died in captivity [Gul Rahman] was determined to have died as a result of conditions" due to his confinement. The deputy director of operations and general counsel asked Helgerson to look into the matters. The inspector general (IG) agreed.

Tenet was required to notify congressional intelligence committees about the probe within seven days. On January 30, he sent letters to the so-called Gang of Four — senators Pat Roberts and John Rockefeller, the Republican and Democratic chairman and co-chair of the Senate Intelligence Committee, and representatives Porter Goss and Jane Harman, the Republican chairman and ranking Democrat on the House Intelligence Committee — advising them of Helgerson's probe into Rahman's death and the death threats against al-Nashiri.

The internal investigations were followed by the special accountability board, convened by CIA Director George Tenet in September 2005, that probed the actions of three CIA employees who were named by the IG in connection with Rahman's death — Zirbel and two other CIA associates. The case was referred to the Department of Justice, which declined prosecution. (In 2011, a special prosecutor appointed by Attorney General Eric Holder to investigate the destruction of nearly 100 CIA interrogation videotapes launched a separate, criminal investigation into Rahman's death and the death of another detainee who died in CIA custody. A year later, the special prosecutor, Assistant US Attorney John Durham, concluded his probe but Justice again declined to prosecute. In a statement, Holder explained "the admissible evidence would not be sufficient to obtain and sustain a conviction beyond a reasonable doubt.")

The accountability board did not recommend disciplinary action for two of the CIA employees. But it did recommend that Zirbel be punished: "a 10-day suspension without pay."

"The Board believes this action strikes an appropriate balance between: 1) the fact that [Zirbel] was the only individual who made decisions that led directly, albeit unintentionally, to Rahman's death and 2) the significant weight the Board attached to the mitigating factors at play in this incident," the review board's report said, according to a summary shared with congressional oversight committee members in February 2006.

But the executive director of the CIA, Kyle "Dusty" Foggo, whose name was redacted from the documents but whose name was unredacted from the Senate's torture report, disagreed. (Foggo, the No. 3 person at the CIA, was sentenced to three years in prison in 2009 in connection with a bribery scheme involving Congressman Randy "Duke" Cunningham.)

According to the accountability board's review, Foggo acknowledged "performance shortfalls" at the black site "but found no disciplinary culpability."

"Although [Zirbel] exhibited poor judgment in his decision to short-chain Rahman and leave him in that condition overnight, there is no evidence, as determined by the IG report of investigation and confirmed by the Special Accountability Board, of any intent to harm or kill Rahman," according to the review board's report, copies of which were shared with a handful of Democratic and Republican lawmakers on the House and Senate oversight committees. Zirbel was a "first-tour operations officer with no experience or training in interrogations or prison operations and the act of short-chaining was a restraining technique taught to the [redacted] guards just prior to Rahman's death by a visiting training team from the US Bureau of Prisons."

It goes on to say that others "in the chain of command were satisfied with [Zirbel's] performance based in part on first hand observations, an appropriate awareness of the interrogation techniques used on Rahman, and the conditions of Rahman's confinement."

But the Senate's torture report said other CIA officers judged Zirbel to be immature and dishonest, and advised against giving him access to classified information. A supervisory officer added that Zirbel's "potential behavior in the field is worrisome."

At the time of Rahman's death, according to the CIA accountability board's report as well as the Senate's torture report, the CIA had not yet "fully developed formal detention and interrogation guidelines; guidance was ad hoc and there was ambiguous chain of command from headquarters." The systemic problems at the black site identified by the IG at the time included a lack of resources, training guidance, and oversight.

"Taken as a whole, these facts and circumstances led [Foggo] to conclude that although the performance of [Zirbel and two other CIA personnel] could have been better, their performance in regard to these events did not warrant the imposition of any disciplinary action," the report said.

Just four months after Rahman died, the CIA station chief in Afghanistan recommended that Zirbel be awarded $2,500 for his "consistently superior work," according to the Senate's torture report.

The CIA's June 2013 response to the torture report said CIA leadership "erred in not holding anyone formally accountable for the actions and failure of management related to the death of Gul Rahman at [COBALT] in 2002."

Ryan Trapani, a CIA spokesperson, told VICE News that Rahman's death "is a lasting mark on the Agency's record."

"One of the key steps we've taken in response to the [Senate torture report] is to ensure internal accountability efforts do not focus exclusively on alleged perpetrators of misconduct, but look more broadly at any systemic problems," Trapani said. "We can't discuss individual personnel issues, but we acknowledge in our 2013 response to the [Senate torture report] that, in some cases, CIA fell short when it came to holding some individuals accountable for poor performance and management failures, even after full investigation and adjudication. We believe greater accountability should have been imposed up and down the chain of command."

The CIA never formally notified Rahman's family about his death. Instead, his family learned of his fate when the Associated Press published a report about his demise in March 2010. Rahman's family enlisted the International Committee of the Red Cross to help retrieve his remains, but thus far have been unsuccessful.