In my country colombia that kind of violence is not common, i think is more about how people grow and how people live, i mean in my country colombia the issues are about drugs and guerrillas because people need to work hard to have bread in table their minds are focused in progress so in rich countries sometimes people have all in hands so they don't see a good reason to live and that's the reason a lot of people have mental mental problems so here the solution could be attend all this cases and the state have to try to give people reasons to live i mean stong culture, about weapons i really don't know how that work outside but thinking about people with mental problems and extremists the state have to creat strong rules and every part of defence have to work together, i wanted to share more ideas but i'm not native in english but that's the whole idea of what i think. Regards