Judging Detainees’ Risk, Often With Flawed Evidence

Military analysts believed him. Mr. Shah, who had been outfitted with a prosthetic leg by prison doctors, was “cooperative” and “has not expressed thoughts of violence or made threats toward the U.S. or its allies,” according to a sympathetic 2003 assessment. Its conclusion: “Detainee does not pose a future threat to the U.S. or U.S. interests.”

So in 2004 Mr. Shah was sent back to Afghanistan — where he promptly revealed himself to be Abdullah Mehsud, a Pakistan-born militant, and began plotting mayhem. He recorded jihadist videos, organized a Taliban force to fight American troops, planned an attack on Pakistan’s interior minister that killed 31 people, oversaw the kidnapping of two Chinese engineers, and finally detonated a suicide bomb in 2007 as the Pakistani Army closed in. His martyrdom was hailed in an audio message by none other than Osama bin Laden.

The Guantánamo analysts’ complete misreading of Abdullah Mehsud was included among hundreds of classified assessments of detainees at the prison in Cuba that were obtained by The New York Times. The unredacted assessments give the fullest public picture to date of the prisoners held at Guantánamo over the past nine years. They show that the United States has imprisoned hundreds of men for years without trial based on a difficult and strikingly subjective evaluation of who they were, what they had done in the past and what they might do in the future. The 704 assessment documents use the word “possibly” 387 times, “unknown” 188 times and “deceptive” 85 times.

Viewed with judges’ rulings on legal challenges by detainees, the documents reveal that the analysts sometimes ignored serious flaws in the evidence — for example, that the information came from other detainees whose mental illness made them unreliable. Some assessments quote witnesses who say they saw a detainee at a camp run by Al Qaeda but omit the witnesses’ record of falsehood or misidentification. They include detainees’ admissions without acknowledging other government documents that show the statements were later withdrawn, often attributed to abusive treatment or torture.

A Growing Wariness

Written between 2002 and 2009, the assessments reflect a growing wariness on the part of Guantánamo analysts. Early on, the reports are just a page or two and often sanguine in tone. By 2008, after scorching publicity about released detainees who joined Al Qaeda and the dwindling of the prison population to hard-core detainees, the assessments are decidedly more cautious.

For every case of an Abdullah Mehsud — someone wrongly judged a minimal threat — there are several instances in which prisoners rated “high risk” were released and have not engaged in wrongdoing. Murat Kurnaz, a German resident of Turkish ancestry, was judged in a 2006 assessment to be a member of Al Qaeda who fell into the most dangerous category: “high risk” and “likely to pose a threat to the U.S., its interests and allies.”

Nonetheless, American authorities, under pressure from both Germany and Turkey, overruled the analysts and sent Mr. Kurnaz home to Germany three months later. He did not join the global jihad but instead became a prominent critic of Guantánamo, writing a book and making countless media appearances to denounce the American prison.

Among the most revealing of the leaked documents is a 17-page guide for analysts, evidently prepared by military intelligence trainers, on how to gauge the danger posed by a detainee. It lists major clusters of detainees, including the so-called Dirty 30, who were the bodyguards of Mr. bin Laden, as well as the large group of accused Qaeda operatives captured with Abu Zubaydah, an important terrorist facilitator, at two guesthouses in Faisalabad, Pakistan, in 2002. It lists nine mosques associated with Al Qaeda, in Quebec, Milan, London, Yemen and Pakistan.

The guide shows how analysts seized upon the tiniest details as a potential litmus test for risk. If a prisoner had a Casio F91W watch, it might be an indication he had attended a Qaeda bomb-making course where such watches were handed out — though that model is sold around the world to this day. (Likewise, the assessment of a Yemeni prisoner suggests a dire use for his pocket calculator: “Calculators may be used for indirect fire calculations such as those required for artillery fire.”)

A prisoner caught without travel documents? It might mean he had been trained to discard them to make identification harder, the guide explains. A detainee who claimed to be a simple farmer or a cook, or in the honey business or searching for a wife? Those were common Taliban and Qaeda cover stories, the analysts were told.

And a classic Catch-22: “Refusal to cooperate,” the guide says, is a Qaeda resistance technique.

Yet the guide appears to be the product of years of experience at trying to turn bits of evidence of varying reliability into a conclusion. Notably, it cites as a cautionary tale the early misjudgment about Abdullah Mehsud, the Pakistani suicide bomber, who had claimed he was forced to join the Taliban. He was “an example,” the guide says, “of a detainee who successfully applied the conscription cover story as a means to secure his release from U.S. custody.”