WASHINGTON - The Supreme Court has ruled that a minimum 30-year prison term for crimes involving a machine gun may not be imposed unless a jury specifically convicts a defendant of using a machine gun. The court on Monday unanimously upheld a federal appeals court ruling that had been challenged by the government. The decision came in the case of Martin O'Brien and Arthur Burgess, who were charged in connection with a failed robbery of an armored car carrying $2... (GunPolicy.org)