Buy gun, become ill....then what?

This morning I read an A.P. article in the Philadelphia Inquirer on Jimmy Lee Dykes, the man who shot and killed a school bus driver and then kidnapped a 5-year-old boy from the bus and held him hostage for days in an underground bunker.  The article said that neighbors described Mr. Dykes as:

 "a menacing, unpredictable man who once beat a dog to death with a lead pipe, threatened to shoot children for setting foot on his property, and patrolled his yard at night with a flashlight and a firearm." 

Based on that description, do you think this man is mentally ill?  Should he be permitted to own guns?

Many people who are opposed to gun control regulations, including Wayne LaPierre, the NRA spokesman, have said that guns are not to blame for tragedies such as the Newtown shooting, but rather that the fault lies with our mental health system.  Mr. LaPierre, testifying before a U.S. Senate committee on 1/20/13 said, "I think we can also agree that our mental health system is broken."  He also said, with regard to a reduction in the number of gun-related prosecutions, "That means violent felons, gang members and the mentally ill who possess firearms are not being prosecuted. And that’s unacceptable." 

The article states that Mr. Dykes served in the military in the 1960s, receiving some awards for his service.  Perhaps he purchased his firearms back then, when he was presumably fully mentally competent to do so.

So....decades later he is acting erratically, routinely threatening people with a firearm.  Should anything have been done about that?  Clearly Mr. Dykes presented plenty of those 'warning signs' that we often claim are lacking prior to a crime.  Would it have been possible to stop Mr. Dykes before he murdered a man in front of dozens of children? 

My sense is that the people who want to blame the mental health system, rather than guns, are the very people who would be most opposed to taking the kinds of steps necessary to address Mr. Dykes' at-home behavior.  Would they support forcing a man to submit to involuntary mental-health testing based on things he said or did while alone on his own property? 

Mr. LaPierre states that it is unacceptable for the mentally ill to possess firearms, not just to purchase them.  Would he then advise NRA members to support legislation mandating annual mental health tests for all gun owners?  Or only for those gun owners whose neighbors are frightened of them?  How, exactly, is law enforcement supposed to prosecute the mentally ill who bought their weapons when they were healthy? 

These are not just rhetorical questions.  Start some dialog - are there any good answers?