At this point in time, with all the weapons floating around in the U.S., introduction of gun control may be pointless. You can prevent people from getting guns legally with gun control, but those that really want them would easily get them illegally. 

I also doubt many Americans would voluntarily hand over their weapons to the government. One of the reasons so many of them acquire such weapons (automatic weapons) is because they don't trust the government and police to protect them. Some of them also are paranoid about the government taking over their rights and freedom with laws such as eminent domain, used to displace people from their property if it is deemed "in the national interest".

We have been lucky in Canada that gun control was instituted very early in our history. We are also lucky that the type of incidents occurring in the States is relatively rare. I hope we don't see many more of those here.