What is it with people always starting to collect the guns after some idiot starts a shootout or a bombing. If you want the crime rate to go down, you could Legalize drugs to destroy the black market, which would defeat organized crime. If you want these damn psychos who open fire in public places because of their own anger disappear, make sure that no child in this world gets to grow up being the target of violence. If you want muggers and crooks to disappear, make a system to give support to all of these people so people who have resorted to crime to get their money get a house. Its that easy. I'm pretty sure the government has enough money to do that.
This whole gun control situation can be easily compared to piracy in video games. The development team puts all of this DRM garbage into the game which forgets the honest consumer who bought the game with their own money, but doesn't do a damn thing for the people who download the game free. If you want piracy to go down, you need to have good services that offer your product for sale easily. If you want murders and all other gun related crime to go down, make sure no one gets into a situation in which taking the law into their own hands is the way to go. Taking guns away from the public and its people won't do a damn thing. Criminals buy their weapons from the black market so there is no paper trail to their identity. If the governments increased their police resources and funding, I'm pretty sure in the end no one would even want to buy guns because there is no point carrying one around unless you like to shoot tin cans at your summer cottage.
"The one who sacrifices freedom for security deserves neither" -Benjamin Franklin.