Memorandum for William J. Haynes II, General Counsel of the Department of the Defense: Re: Possible Criminal Charges Against American Citizen Who Was a Member of the al Qaeda Terrorist Organization or the Taliban Militia [December 21, 2001] [open pdf - 2MB]
"This is to provide you with a review of criminal charges that might be brought against John Walker, a United States citizen captured in Afghanistan while serving with enemy forces. As we understand it, Mr. Walker was captured by the Northern Alliance and was interrogated by American intelligence officials accompanying them, including John Michael Spann, a Central Intelligence Agency officer. Mr. Walker was present during, and may have played some role in, the revolt of Taliban and al Qaeda prisoners at the Qala-I-Jangi fortress, in which Mr. Spann was killed. Mr. Walker apparently joined the Taliban about six months ago and thereafter at some point also joined al Qaeda. He has reportedly said that he joined a military unit to fight in Kashmir against India before the September 11, 2001 terrorist attacks on the United States. According to press reports he is now being held aboard the 'U.S.S. Peleliu' in the Arabian Sea. We conclude that several criminal charges could be brought against Mr. Walker in different fora, depending on the facts. He could be charged in federal court with treason, killing a federal employee, assisting a terrorist organization, or unlawfully participating in foreign affairs. In addition, Mr. Walker could face prosecution in a court-martial for either aiding the enemy or for war crimes."
U.S. Dept. of Justice: http://www.justice.gov/