GUANTANAMO BAY, Cuba — A veteran U.S. Army officer who agreed with President Barack Obama that the Guantanamo Bay prison should be closed was excluded from the jury in a U.S. military commission trial Wednesday after prosecutors objected that he had "pre-conceived" views that might jeopardize their case. The move came as prosecutors and jurors selected a seven-person jury of military officers to hear the case of Omar Khadr, the so-called "child soldier" accused of hurling a hand grenade that killed an American soldier in a firefight in Afghanistan eight years ago. Khadr, now 23, has spent a third of...