U.S. senators on Tuesday heard testimony in the first of several planned congressional hearings examining ways to try prisoners at Guantanamo Bay, after a Supreme Court decision last month declared illegal the “military commissions” established to try the detainees. Over two sessions totaling almost four hours, Republican and Democratic members of the Senate Judiciary Committee listened to and questioned administration lawyers, law professors, and military attorneys about the old trial system, and ways to construct a new process. The hearing was convened after the Supreme Court last month upheld a challenge to the military commissions, brought by Yemeni detainee Salim Ahmed Hamdan. The court ordered the government to consult Congress on establishing a trial process that would comply with U.S. and international law. Much of Tuesday's testimony dealt with the possibility of trying the 450 men held at the controversial detention facility before military tribunals in accordance with the U.S. military's own rules – the Uniform Code of Military Justice (UCMJ).