They should restrict or prohibit the sale of weapons, that's the first step! I think you don't need to carry a gun in a shoot-out. That wont help you to defend yourself because you will probably be killed swiftly. If the arms are already here, why do you want to buy more arms? That will only cause more deaths. They can increase the security in general, then they can focus on the real criminals. Those criminals will be arrested and taken into custody. We can control our actions, but we can't control the actions of other persons. There are many people trying to get money through the suffering of millions of people and there are also people with mental problems. That's the reality in which we live. There is no turning back.