They work as well as all other laws work in that only the law abiding obey them. If you think any more laws will keep this stuff from happening then you are wrong. It's clear from your comments that you want some kind of new laws and it has been proven time and again they don't work. But, why didn't we have all these mass murders back 60 years ago? People have changed, that's why. No laws will stop this until the people change or the people take it upon themselves not to allow this crap anymore by becoming pro-active. No laws will stop it. By the way, murder is against the law. Why didn't that stop it?