I think a convincing case could be made that violent video games play a big role in these shootings. Semi autos have been around for over 100 years before these mass shootings started. Why have these started in the last 20 years? The difference is the appearance of ultra violent first person shooter videogames that desensitize people to killing. The military even uses these as training tool to get soldiers accustomed to shooting people. You have generation of young people who grew up with these games and shooting realistic looking game characters may their inhibitions to shooting real people.
The left is going to push hard to blame this on guns. I think videogames offer a more convincing explanation that we can use as a strong counter-argument..
Just think about that for a second. Video games on a TV with a game controller compared to the real life head of a loved one blown off. If you took a teenager out back and blasted the family dog with a shotgun, they'd be horrified, let alone a guy shooting his own mother in the face to start.
There is a real, tangible gut wrenching emotion that a normal person feels when exposed to real life trauma.The sound of the gun, the smell, the blood and brains and the look of a person's blank dead eyes that can't be imitated by some zombie video game, if the guy even played them, and there doesn't seem to be any evidence I've heard so far.
Only a socio/psychopath can do something like this; a person who would torture animals as a child and worse because he has no ability to empathize with anyone or anything. I think it'll probably come out that the guy tortured animals but was not able to be dealt with for a variety of reasons. I predict this tragedy will turn out to be a failure of the juvenile justice/mental health care system above anything that relates to gun control.
But, nonetheless, a socio/psychopath like this can't be cured anyway. We can only hope they eliminate themselves before doing something like this.