The Supreme Court won't hear a Maryland man's argument that the Second Amendment allows him to carry a gun outside of his home for self-defense.

The high court on Monday refused to hear an appeal from Charles F. Williams Jr., who was arrested in 2007 for having his legally-purchased handgun outside his home without a state permit.

The high court has ruled there is a right to keep a gun in the home for protection. But gun advocates say people also have the constitutional right to carry their guns outside the house for self-protection.

Maryland courts say if the Supreme Court agrees with that theory "it will need to say so more plainly." The high court refused the opportunity on Monday.

The case is Williams v. Maryland, 10-1207.