Al-Nashiri was flown to a black hole prison in Poland in 2002. According to the Inspector General's 2004 report,(see page 42)he was tortured. First, there was the waterboarding (the videotapes of which were destroyed.) But then, there was the threatened use of a power drill, which the interrogator turned on and started whirring, while al-Nashiri was naked and hooded in his cell.

The CIA official who threatened him with the gun and powerdrill was named Albert. He was an FBI agent employed as a bureau translator in New York before joining the CIA. He was reprimanded and left the agency. DOJ refused to bring charges against him. He was rehired as a CIA contractor in 2008, training CIA officers in northern Virginia . As of 2010, he was working as a contractor in the private sector. His supervisor who approved the use of the power drill and other threats was named Mike. He retired in 2003. (Timeline here.)

Al-Nashiri, a Saudi, was transferred to Guantanamo in 2006. The DOD's summary of evidence against him at the Combatant Status Review Tribunal is here.

The military tribunal rules will allow hearsay evidence that would be inadmissible in a federal criminal trial. The New York Times says:

Much of the evidence against Mr. Nashiri consists of witness interviews and documents gathered by the F.B.I. in Yemen after the bombing. Prosecutors may call the F.B.I. agents as witnesses to describe what they learned during their investigation — hearsay that would be admissible under tribunal rules, but not in federal court.

Al-Nashiri's trial will highlight another issue:

[W]hether a state of war existed between the United States and Al Qaeda at the time of the Cole bombing — before the Sept. 11 terrorist attacks and the authorization by Congress to use military force against their perpetrators.

...[T]he government now contends that a state of armed conflict had legally existed since 1996, when Osama bin Laden declared war against the United States. The question is important because military commissions for war crimes are generally understood to have jurisdiction only over acts that took place during hostilities.

Al-Nashiri wasn't just sent to an overseas black hole prison once, but twice. In 2004, the Bush Administration, fearful of the imminent Supreme Court ruling on whether detainees could have access to the courts, sent a Gulfstream to Gitmo and whisked al-Nashiri and three other detainees, Abu Zubaydah, Ramzi Binalshibh and Mustafa al-Hawsawi, back to the overseas secret prisons.

Attorney General Eric Holder stated unequivocally at his confirmation hearing that waterboarding is torture. It remains to be seen whether Obama will seek the death penalty against al-Nashiri.