Just a few thoughts:
1) 2nd Amendment needs to go. Owning a gun is not and should not be a natural born right. I'm not saying guns need to be banned, but the starting point in any gun debate should not be "I have the right to one, prove why I shouldn't". The gun control discussion should be, "prove to society that you are a physically and mentally capable person, then you can have one". Self defense is not a legitimate reason. Australia has actually criminalized self defense with a gun. They also have a gun mortality rate one third of the US.
2) There are entirely too many guns in the US. Under current estimates, there are literally one gun for every man/woman/child in the US. Next closest one: Serbia with 1 gun per 2 people (just over half the rate). Most European countries are around 30 guns per 100 people. With this many guns available, it should be of absolutely no surprise that anyone can get one if they want one. The US has doubled the amount of guns per capita over the last 40 years and the only thing that has proven is that more guns do not solve the problem. When tools are available, said tools are used.
3) Mental health in the US is abysmal. Yes, the US has some of the best medicine available in the world. But there is a difference between being available and genuinely accessible. Lamborghini's are available, but only select few have access to them. Why is healthcare the same way? People have to make the daily decision between food and buying their meds. Bankruptcy should not be a consequence of getting sick. You want to know what socialized medicine provides? It provides help those who need help. I don't care if you're healthy and don't need it, your current health is just one mental break away from being a victim from someone who can't afford their meds. Healthcare should not be a capitalist commodity to be profited from on the stock market.
The United States has 10 gun-related deaths per year per 100k people (6.3 of that is suicide). This is worse than South Africa, Philippines, Mexico, Serbia, and Israel. Compared to other developed countries (mostlly European), Americans are 10x more likely to die by a gun.
"How are we to protect ourselves from an oppressive government?" Oh, you mean the government that spends almost $600b PER YEAR on a military force? Good luck with that.
"But I am safe with my firearms." Good for you.
Yes he is a hero for shooting back. And the bad guy.... He's a piece of garbage. And let's face it, these guys mental or not, are evil at the core. And they don't respect the laws. That is obvious enough. I truly believe that had more of these incidents occurred where someone armed was nearby to act in defense, 1) there would far less casualties; and 2) these incidents might be far and few between.
Exactly proving my point. With a gun, he's a hero. No one else is identified as a hero. If a police officer arrives on site to see two people shooting each other, who's the bad guy? Most people who conceal carry won't even un-holster their weapon because 1) they don't want to become the target of the bad guy and 2) they don't want to be labeled as the bad guy when the police show up.
The bad guy is a bad guy, it's nothing to do with poor mental health treatment options, nothing to do with access to the largest array of weapons in the world, and definitely not society's fault for fostering the whole situation. Right?
At the end of the day, what the US is doing is not working. De-regulating guns (per the NRA goal), is not working. Everyone having the right to own one is not working. When is the US going to start looking outside it's own borders to see what other countries are doing? Why is suggesting what other countries are doing being met with such resistance? I'm not saying the rest of the world has it perfected, but it's significantly safer out here...