The problem is not the gun, which is an inanimate object utterly incapable of any thought or action of its own. The problem is also not a lack of legal sanctions against improper use of firearms. When last I checked, it was already a violation of a substantial number of laws to enter a school and shoot people. Passing more laws will not deter those who would do such things. The problem is in man's heart, and that is where we must look for the solution.
Man is capable of making moral choices.
The choice to shoot someone inherently involves making a moral decision. You must decide whether to defend your home and family or to accept the protection offered by the state as your only shield against those who would prey upon you. Ultimately though, you do not have the right to decide that I no longer have the right to own weapons and make my own moral decisions. We could, as a society, pass a constitutional ammendment and ratify it at the state level which would alter or abolish that right, as we could for our vital right of the franchise. But this would no longer be the America that we were given by our ancestors.