Just semantics, I know, but we often misuse the word "weapon"
Just for the sake of being better informed, the guy out in Colorado did not use an assault "weapon" or any other kind of "weapon" in the commission of his crimes. What he used were firearms. You see a weapon, by definition, is a thing you use in a fight. In Colorado there was no fight, it was a slaughter. Just as a guy sitting on a fence shooting cattle in their heads as they are ushered into the gutting room it is a firearm in use, not a weapon being employed in a fight with cows. It is equally true that you do not shoot at targets with a weapon, linguistically that's the realm of firearms, or guns, or whatever else you might want to call the things. But when armies or gangs fight one another their guns are weapons, when they use knives the knives are weapons, if they were to beat on each other with hammers then the hammers would properly be called weapons too.
Just thought you would all like to know.