Well, it starts with enforcing law. When you say loud and clear to somebody if you're going to carry a gun illegally, we're going to arrest you. If you're going to sell a gun illegally, you need to be arrested. If you commit a crime with a gun, there needs to be absolute certainty in the law.
Carrying a gun illegally can get you arrested.
( z1 possible :ARG1 ( z2 arrest :ARG0 ( z3 carry :ARG0 ( z4 you ) :ARG1 ( z5 gun ) :ARG1-of ( z6 legal :polarity - ) ) :ARG1 z4 ) )