The reaction we get from mass murder is foremost emotional. We think there must be some way to prevent it, so we look around to ban or control something.

It is almost impossible to stop a determined AND trained person from doing almost anything he or she wants, at least for a short period of time.

Can you stop suicide bombers by making suicide by explosives illegal?

How do you stop a mad person with a motor vehicle?

How do you stop a person from driving an airplane into a building?

Frankly, I don't have the answers, but I don't think the answers will be based on an emotional response.