Let's remember who was at fault: it was an ugly collaboration of the left and right. The left said people had a right to be insane, that it was a natural condition and shouldn't be a cause for incarceration. The right said look at all the money we could save by shutting down these large, costly facilities that warehouse the incurably insane.
Together they closed down the places where the Jared Loughners of this world could be treated and more importantly, we could be kept safe from them. It appears Loughner is another sad case like the shooting at Virginia Tech by Seung-Hui Cho.
As a result of closing mental hospitals we have the insane living on the streets, under bridges and sometimes on college campuses. From time to time one acquires a weapon and does awful things. The fault is ours for letting it happen.