That´s why I love being scandinavian. Nobody carries a gun*.
*Organised crime exists of course, but they use their weapons on other gangs...
In my opnion, when you allow people to arm themselves, you effectively start an arms race within your society. Criminals need to arm themselves more to overcome armed citizens, police needs to arm themselves even more to overcome the more heavily armed criminals, etc, etc: an arms race.
When a policeman shoots in the Netherlands, it is news.