The man, identified as Mouafak Al D., according to German reporting custom, is accused of war crimes in Syria, fighting for a militia on behalf of President Bashar al-Assad’s forces, the prosecutors said. The civilians at the Palestinian refugee camp of Yarmouk, south of Damascus, were part of a crowd waiting for food aid when a man fired at them from an anti-tank weapon, killing seven and severely wounding three, including a six-year-old child, the authorities said.