Healthcare is a responsibility. Gun control is seeking to usurp the ability of someone to defend themselves from others. Gun control ensures that the only people that are carrying are criminals. Why is the gun violense so bad in Chicago when they have gun control?
I would agree tentatively that pychiatric care may have helped. But even the best healthcare cant always predict when someone will have a psychotic break that allows them to engage in this sort of behavior.
The problem with a free society is that its not very neat and its not very controlled, but people are free to make their own choices. Unfortunately some of those choices are so horrific that we turn away from our principles and seek to control what others do, when something like this is both hard to predict and hard to prevent.