The country with the lowest gun crime in the world is Switzerland. It requires everyone of age to own, and practice with assault weapons. Carrying the weapons is encouraged by the government and it is quite common to see a couple out bicycling and stopping in at a local rest stop with assault rifles strapped on their backs. They have no gun crime at all and their violent crime is as low as it can get.
They don't have people shooting up the mall or the school because there are any number of people that would kill anyone who tried such a thing.
Guns make for a polite society.....
That's not true. Switzerland had 40 Gun Homicides in 2010 and 55 in 2009.
Japan had 11 gun homicides in 2008 (the last year we have figures for.)
Now, that sounds like Japan has a better handle on this problem by banning guns, especially when you consider Japan has 110 million people and Switzerland has only 8 million.
Switzerland also has socialized medicine, and everyone who is mentally ill gets treatement.