I have long been in favor of the "Mandatory Armed Store Clerk act" for convenience stores, gas stations and liquor stores.
A requirement for employment in such businesses should be that you have a concealed carry license, and that you be armed if you are at work.
Make sure robbers understand they have a very good chance of getting shot to death, and they will stop thinking about robbing stores.
Hmmm, since there are so many building codes anyway...how about an extra that requires a small fortified area where an armed guard could shoot at would be robbers? It should be constructed such that there should be no way for a thug to verify if a guard is there...except the hard way.