If guns were illegal then the massacre might've been even deadlier.
It's possible that in trying to gather weapons that he'd be busted in the process. OTOH, people like him and of his background manage to score illicit drugs all the time with no problem. (Heck, given our surveillance state I think it's a legite question to ask why no red flags were raised over his buying all the things he did in the last few months, though I suppose the government is far more concerned with OWS, moderate Muslims, and even environmentalists.) And if on the black market in a society where legal guns are banned then he'd be much more likely to get the guns (and more lethal types of ammo) restricted to the military and law enforcement meaning even more dead & wounded.
Or he might've chosen an alternative route. Molotovs seem most likely though napalm and worse are very easy to make with items easily obtained at many grocery & convenience stores (and stores selling lawn & garden products for the really nasty stuff). Given his expertise he probably could've wired up something really deadly and set it off with his cellphone, and had guns not been so easy for him to get he might've took the time to realize that.
I do believe that in many cases most mass shooters would be severely hampered by strong gun control laws, but not in this case. (But I also believe that while armed citizens can--indeed, have--stop such people in their tracks, they probably wouldn't have in this case, though perhaps it might not have been as bad, but then it's possible it could've made it even worse as well.) The problem is that I'd see a general INCREASE in violence with strong gun bans because criminals and other violent people would become even more aggressive, and of course many criminals would still get their guns and they'd tend to be even deadlier than they are (and they'd be a lot bolder about using them, and if there are draconian legal penalties against their use they might be a lot less willing to be taken alive, which isn't just bad for the cops but bad for anyone who gets in the way of such a desperado). That is to say I'm pretty sure that there'd be a lot more tragedies, fear, and maybe even killings (gun and otherwise) with strong bans against guns than with the ease they're gotten now.
Still, this incident has upset me greatly and I know it has others as well. I went to the movies today and there were a lot fewer people than usual (I bet many worry about copycats who crave similar infamy that the media is all too willing to give them), one was making jokes that sounded like nervousness, and (though this may be irrelevant) I smelled cannabis as if someone just toked (which I haven't in a long time). This is a terrible tragedy and I don't blame people for grasping at straws. But I hope people can get to the root of this problem without the usual insistence in a mythical magical one-shot solution made of baseball, apple pie, and the bible with an Uncle Sam stamp on the front cover.
Don't get me wrong, I'm not a "guns for everyone" type of person and have no problems with vetting people, mandatory safety courses, waiting periods, and the like (and if we're gonna have a surveillance state anyway then things like this need to be looked for, that is it should be used to protect the people, though I understand that's just not gonna happen, "safety" is the excuse but in reality that's meant for the corporate & political elites, not the little guys like us). But just going after guns (or video games, or "not enough God" and a host of other things) is going after a symptom and not a solution and likely to make the problem even worse instead of better. The Swiss seem to have very few of our problems despite sights like this (and less religion than the USA):
(Btw, quick note, the Swiss banned violent video games a couple of years ago, IIRC, but this pic was taken before then.)
The question I hope people ask is why do countries like the USA, UK, Russia, and Mexico (all but the USA having strict gun control, and the most violent parts of the USA tend to have the most gun control) have such problems but the Swiss do not?