The Supreme Court on Tuesday overturned a lower court ruling from Pennsylvania that allowed residents under 21 to carry firearms in public, though the justices declined for now to hear arguments in the case themselves. At issue was a state law that barred 18-to-20 years olds from open carrying firearms during declared states of emergencies. The court’s decision tosses a federal appeals court ruling that found the law violated the Second Amendment. The Supreme Court did not explain its ruling and no dissents were noted.