So for people that love their guns, the solution is more guns. Everyone need to be armed and everyone should have the right to conceal and carry into any event or building. Why have a gun license if you cannot carry it everywhere you go. Having to go to the car and get your gun while someone shoot up a building isn't going to resolve the situation fast enough.
The more armed American citizens there are, the better to respond to such incidents. Of course the problem is that not everyone is given the same rights to carry a gun when the police show up. If your skin is any color with a shade to it, the likelihood that you get shot first before they find out it was not you is high.
Either way, nothing will change in America. Americans love their guns, big money is behind selling guns and just like healthcare as some mentioned saving lives isn't really a high priority to Americans. Protecting their rights is way more important than any solution to stem away death.