Dr. Joyce Brother was Skinnerian rat psychologist who went media expert.
There is a large literature on whether video games have any predictive validity as to causing violence. The initial wave was that in the lab, kids exposed to such would act out against dolls. In adults, after seeing violent videos subjects would act more aggressively against others. How - well, they honked horns louder at people who made mistakes, put more tabasco sauce in drinks they made for others or recognized negative words faster.
This was challenged as not being able to be linked to real world violence. In many cases, the findings didn't replicate or the effect lasted only a few minutes. So many current researchers doubt the effect. Dr. Brothers is not a source.
But if you want to make the case as Wayne LaP. did that violent video games are a problem, the same exact methodologies demonstrate that exposure to guns or images of such produce the same effects.
He can't have it both ways.
There is good evidence that exposure to guns can influence decisions in mock jury deliberations. That's quite different from pushing someone to be a rampage shooter.
And - if you argue that we need religion in the schools - the same methodology has 'demonstrated' that religious passages containing violence also make you think more aggressive thoughts.
So pick your poison. My read of the real literature and not some idiot talking head is that we can't demonstrate that someone is pushed over the edge by media.
What you have is more complex. The shooters are fundamentally disturbed. They are vulnerable to hostile ideation and then they seek out representations that confirm their beliefs or instruct them. Studying Columbine and VT are common among the ones caught before they could carry out a rampage. But the study of such is driven by the pathology.
To avoid this effect, we would have to totally control news media, historical sources and religious texts. No more WWII on the History Channel. Hardly any current movies, etc.
Fundamentally sound folks are not driven over the edge by exposure to games, media, guns or God. Do we control all of these for those who are not stable? That is a very small number.
Wayne thought he was clever in diversion but it was not really a telling argument. If he buys into the media violence connect, he has to buy into a violence and gun connection as both are part of the same aggressive priming paradigm.