In the decade and a half since Australia initiated the policy, the number of firearms per person has stayed constant, and gun deaths have remained low. Sometimes a tragedy is so awful that it changes the national debate. The 1996 Dunblane school shooting in Scotland and the 2011 Norwegian gun massacre all prompted an outpouring of anguish and a demand for changes in law. In Australia, that moment was the 1996 Port Arthur massacre, in which a gunman killed 35 people at... (GunPolicy.org)