According to the NY Times, the shooter in Newtown used a Bushmaster M4 assault rifle. There are barely any reasons for this type of weapon to exist at all, and absolutely no real reason for civilian models of this weapon to exist.
I heard discussion of using these weapons for self-defense; some even stated that people of minority groups often targeted by police brutality need access to the same weapons the police has access to, for self-defense. Really? Has that ever worked? The police, for better or worse, has the near-monopoly of violence in our societies. Is there statistic evidence that people defended themselves from (police) brutality with these types of weapons. Don’t use of these weapons always make everything worse? Is it really worth it?
I don’t think guns are the reason for tragedies like this. But they do make them even worse.