Terrorist recordings: A new book says the U.S. military feared the use of recorded comments made by the 9/11 mastermind.

A10

WASHINGTON — A new book says Justice Department prosecutors were stunned to learn three years ago that the U.S. military had secretly tape recorded incriminating comments that alleged 9/11 mastermind Khalid Shaikh Mohammed made to fellow detainees during daily prison yard conversations but was not planning to use them at military tribunals.

In “Kill or Capture: The War on Terror and the Soul of the Obama Presidency,” journalist Daniel Klaidman says Mohammed was caught on tape boasting to other detainees about the 9/11 attacks. According to the book, Mohammed mentioned specific pieces of evidence, documents and computer files that could be tied directly to him through his voluntary statements to other detainees at the military detention facility in Guantanamo Bay, Cuba.

Justice prosecutors were surprised because civilian prosecutors regularly use the jailhouse statements of inmates against them at trial and because the statements, voluntarily uttered, would allow the government to get around the problem of using statements the detainees made during harsh interrogations that defense lawyers would try to exclude from trial as tainted by torture.

Mohammed’s conversations “were intercepted by military spies and mined for intelligence,” Klaidman writes in his new book. “There were hundreds of hours of such recordings, including musings by KSM and other high-value detainees, uttered freely, during unguarded moments.”

It is unclear whether the military has changed its mind and now plans to use the recordings against Mohammed at his upcoming military commission trial. On Wednesday, a Pentagon spokesman, Army Lt. Col. Todd Breasseale, declined to comment.

Klaidman writes that despite “the potential gold mine” the recordings represented, military prosecutors decided a number of years ago not to use the evidence.

In fact, “they refused to even listen to the recordings,” Klaidman writes. “They worried that the intrusive means by which the evidence was obtained might not pass muster with their judges.”

Military tribunals were barely four years old at the time, largely untested and with practically no case law built up to guide lawyers, the military prosecutors were reluctant to take any chances, Klaidman writes.