EDIT: I see my post is being downvoted. I know that it may come across as insensitive to immediately leap to the gun control debate, but frankly I'm more angry than upset by this news. How many times does it have to happen? We have a good 48 hours of emotional outpouring and then everyone forgets it ever happened.
Was the Oklahoma-city bombing a wake-up call for "explosives control"? Was the 2009 Chengdu bus-fire (http://en.wikipedia.org/wiki/2009_Chengdu_bus_fire) a wake-up call for diesel control? Was the Osaka school massacre (http://en.wikipedia.org/wiki/Osaka_school_massacre) a wake-up call for knife-control? Was the 2012 Toronto mall shooting a wake-up call for gun-control in Canada, which already has extremely stringent gun-laws?
It's all too easy to blame the gun in these situations, but guns are just tools, as are knives, and diesel fuel, and even explosives.
It's not the gun. It never was the gun. It's the person.
So what if it's the person? How can you find those people and stop them from getting guns? All the people who knew the shooter in the Oregon mall shooting a couple days ago said that he showed no signs of being anything other than a kind and friendly person. He showed only a marginal interest in guns. But that could describe hundreds of millions of Americans. You would never be able to find the ones that might do this and make sure they don't get guns.