I don't *blame* the gaming industry any more than the gun industry or the entertainment industry for these shootings.
If it wasn't an AR-15 it would have been a rifle or shotgun or something else. If there were no guns, obviously shootings wouldn't happen but violence would still exist. But that isn't the world we live in, and we make violence "easy". And before that little switch in your brain flips and you think for a second that I am saying we should ban or take away ANYTHING (guns, video games, movies) then you are 100% wrong. More laws are not the answer and are far from it.
What I think needs to change is our attitudes towards violence. OUR attitude. EVERYONE has a part to play in this, and it has to be voluntary. The NRA needs to get their heads out of their asses and realize that providing access to any type of firearm with no restrictions or checks will make it much easier for everyone to have guns - and that includes people who really shouldn't have them. (and yes, I know that determining WHO that is would be nearly impossible). But we have to try. Movies/TV/Entertainment companies (including video gaming industry) needs to understand that they DO glorify violence. We are inundated with violence, from FPS games to movies to TV shows. I don't watch any of them, but there are entire series of TV shows around horribly violent acts (CSI, etc). If you can step back for a second and look at it all holistically - it is very saddening.
I think that Jon Stewart and the Daily Show said it well when they said we have to change our attitude and culture around guns. They likened it to smoking. The message has to change, the overall general attitude towards things. Think about these trials that occur, like the Jodi Arias trial. It was a horrible murder, but let's be honest - in this country and world it happens a lot. But there are shows that are dedicated to follow the trial, to examine it, to discuss it in such desensitizing detail that it is sickening. I really don't get the whole obsession that people have with violence. It's why I quit watching the local news. Over time, I think that it really starts to alter your way of thinking about the world. If any of you have kids, especially boys, then there are nerf guns and foam swords and killing this and that, good guys vs bad guys... again, nothing new. But that can't be our only message that they see, and it is harder and harder to shield them from that. My own kids had to go through a "shooter" drill at school, and that is how they learned about the Newtown shootings. They are in K and 2nd grade!
What I would really like to see is the video gaming industry to take some kind of responsibility for this - not because they are at fault, but because it is the right thing to do. And not by slapping ratings on games, or limiting sales to minors, or anything like that. But by really taking an internal look at what they are producing and self-regulate it. They have the power to influence through what they do, and I think the message being sent is a very harmful one.