Both Attorney General Eric Holder and White House spokesman Robert Gibbs did not rule out a military trial when asked Friday about the Obama administration's options.
Trying Mohammed in military court would mark a further political retreat from Holder's announcement last year that Mohammed and the four other Sept. 11 suspects now held at the U.S. military prison at Guantanamo Bay, Cuba, would be tried in federal court in New York.
The Obama administration is trying to head off a possible vote in the Senate that could stop any terror suspects currently held at Guantanamo from being brought to the United States to face a civilian trial. Sen. Lindsey Graham, R-S.C., is offering such legislation, after losing a vote last year on the issue.
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"These al-Qaida terrorists are not common criminals," Graham said Saturday in the Republicans' weekly radio and Internet address. "A civilian trial of hard-core terrorists is unnecessarily dangerous and creates more problems than it solves."
At stake is the public perception of the administration's handling of national security, already shaken last year by strong congressional opposition to transferring any Guantanamo detainees to American soil. A Hill defeat over the trial issue could embolden the GOP minority to raise national security concerns in the midterm elections later this year.
"Military tribunals are the best way to render justice, win this war and protect our nation from a vicious enemy," said Graham.
The prospect of such a vote could test of how many moderate Democrats have abandoned Obama on the issue.
White House officials said Friday that Obama and his top advisers will play a direct role in ultimately deciding how to prosecute Mohammed. The administration initially decided to try the five terror defendants in New York but have since appeared to backtrack.
"Obviously there are efforts on Capitol Hill through legislation to restrict either the type of or the venue of a trial for Khalid Sheikh Mohammed and his co-conspirators," Gibbs said. "That, by definition, involves the White House and ultimately the president."
"So, since this effort has moved from strictly a Justice Department decision to something that's in the legislative arena, the White House
- and by definition the president - are involved."
As a result of Holder's decision to seek a civilian prosecution, Bush-era military charges that had been pending against the five suspects were dismissed last month. Those military charges could now be revived.
The administration is reconsidering Holder's plan to put the five men on trial in a federal court in Manhattan, after local officials there balked at security and logistics complications.