“The Department of Defense is committed to the integrity of the ongoing court martial proceedings of Major Nadal Hassan and for that reason will not further characterize, at this time, the incident that occurred at Fort Hood on November 5, 2009,” Pentagon spokesman George Little said in the statement. “Major Hassan has been charged with 13 counts of premeditated murder, and 32 counts of attempted murder. As with all pending UCMJ matters, the accused is innocent until proven guilty.”

But Mark Zaid, a national security law expert who sued Libya for the 1988 terrorism bombing of Pan Am Flight 103, said he doubted the government’s hesitancy to designate the Fort Hood assault terrorism was really motivated by concern about prejudicing his trial.

“I find that a little difficult to believe,” he said. “If that was the case, than how in the world would the Pentagon prosecute any terrorism case? There is a process in any case — whether military or civilian — to deal with any potential bias of a juror. It’s a fundamental part of the judicial system to ensure that juries are impartial.”