Who knows what stronger measures there are to take. Anybody that does mass murders like this is not a rational thinking person. Bad people are going to get their hands on guns if they really need to. There is a insane amount of guns in this control as it is.
I can see possible mental health checks for gun applicants, but even then, a lot of these mental fools aren't exactly idiots. It wouldn't be hard to get around this.
I would like to see security employed at schools, armed. A few security guards just to make sure there is a line of defense for our children and to let these dudes know that they will have a fight waiting for them, because a lot of these mental rejects are pure cowards and it shows, shooting defenseless children and teachers.