I won't get too deep into the gun control debate, but I will say this. Stricter gun laws do nothing to prevent crimes and anyone that thinks they will are just simply kidding themselves. Murder is a crime but that doesn't stop people from committing it does it.
People can, and will get weapons to commit crimes no matter what the laws are, be it gun, knife, IED, baseball bat, chemicals you name it, there's many ways to commit heinous and senseless acts towards your fellow man. Legally or illegally owning a gun is honestly a null point in cases of crimes. For those that are mentally ill or not mentally ill, if they can not get a gun legally then they will simply get one illegally (a lot easier than you would think in certain areas trust me) or they will just use some other means of mass murdering people such as just running them down in his car.
Honestly there is too much garbage after an incident like this happens where both sides of the debate as well as the Government waste so much effort and time talking and fighting about gun control when they should be addressing the real underlying problems. Which is proper treatment for mentally ill persons, and stricter punishments for criminals rather than slapping people on the wrist and letting them back out into the world (not the case here but is the case in other incidents).
The other thing that obviously the Gov has no control over, but which I believe is another main reason for senseless murders ...and that is the deterioration of morals/values and improper upbringing over the past two decades. There's been more senseless murders like this over the past 20 yrs than there ever was in the 50 yrs before that, there's a reason for that and it's the way society is these days.
Anyway that's all I'll say about this because this sort of discussion can get pretty emotionally fueled and I don't like to get too deep into them, but the above is my .02 for what it's worth.