No, I'm not willing to get derailed and bogged down into specifics that can be argued or refuted right now. Sorry if that's not your intention but it's hard to judge and it's a very common one with this subject.
I am not an expert on public policy, violence, jurisprudence, or legislature. It's not my place or responsibility to design or implement the solution to this problem.
I'm a citizen who is not willing to accept that routine events like this are an acceptable cost to pay for any freedom. There are probably a wide range of policies that could prevent this, it's up to experts to figure it out. My role is to demand that they do.