The first Guantanamo war crimes trial began yesterday with a not guilty plea from a former driver and alleged bodyguard for Osama Bin Laden. Salim Hamdan, a Yemeni, entered the plea through his lawyer at the US naval base in Cuba. He is the first prisoner to face a US war crimes trial since World War II.Judge Keith Allred, a navy captain, called a jury pool of uniformed American military officers into the courtroom for questioning by lawyers on both sides. A conviction on charges of conspiracy and supporting terrorism could lead to a life sentence for Hamdan. "You must impartially hear the evidence," Allred told the potential jurors. "He must be presumed to be innocent." The 13 officers were handpicked by the Pentagon and flown in from other US bases over the weekend. Hamdan's lawyers asked if they had any friends or family affected by the Sept. 11 attacks to see if any should be excluded as too biased to serve. A minimum of five officers must be selected for a trial under tribunal rules.