Stricter gun laws do absolutely nothing. You can pass all the laws in the world but when you are dealing with someone who is mentally ill they are going to do what ever they want to do.
The very definition of a criminal is someone who breaks the law. There has never been a threshold, the number of laws, that has ever prevented a criminal. No criminal has ever said, "Golly, I was about to go shoot up a liquor store tonight but the president just signed the 3,924,430,234,340th new gun control law. 3,924,430,234,339 is my limit, I won't break any more laws."
99.9999% of all gun laws only punish the law abiding.