We're so much better at treating mental illness than we used to be that I really think a lot of this is treatable.
My heart goes out to the families of shooters as well as the other victims of their mental illness. I'd sure like to try and see if we could find a balance point that protected more people while still leaving the Bill of Rights intact. I think there is room for movement.
If I'm protecting your right to murder people and then take your own life I don't feel like I'm actually helping you.
That being said, I do not think that there is any way for laws to stop all evil or illness.
Gaily bedight, A gallant knight In sunshine and in shadow, Had journeyed long, Singing a song, In search of El Dorado