Justices: Proof needed that person knew he couldn't have gun

The Supreme Court says prosecutors must prove that people charged with violating federal gun laws knew they were not allowed to have a weapon.The government says the decision could affect thousands of prosecutions of convicted criminals who are barred from having a firearm.The court ruled 7-2 Friday in the case of a foreign student from the United Arab Emirates who took target practice at a Florida shooting range, even though he had been dismissed from the Florida Institute of Technology and was