The accused mastermind of the September 11 terror attacks is facing a military judge in his long-awaited first public appearance before a war-crimes tribunal. Khalid Sheikh Mohammed and four alleged co-conspirators have taken their seats at defense tables before Judge Ralph Kohlmann, a Marine colonel. Their arraignment Thursday is the highest-profile test yet of US military's controversial tribunal system. It comes seven years after the attacks. All five face the death penalty if convicted.