We have an alarm system with pads around significant places. So one can press the button to sound a loud obnoxious uproar and it calls the cops.
However, never open the door. If you don't like guns, we have a pepper spray right by the door. Call the COPs first! Not hubby.
Another reason, if you want guns - to carry one. Door gets kicked in and you have to get to the gun. Might not make it. Most folks can carry a little one if need be.