There's no good reason why violent video games should go under renewed scrutiny after what happened yesterday. What happened yesterday isn't new, was bound to happen, and will continue to happen in the future. If anyone is genuinely interested in minimizing these kinds of terrible events then there's better ways to spend your time, money, and energy than blaming the entertainment industry.
Write letters, protest, and be good hearted to everyone.
Fight for a compromise on gun control. Where we ban automatic weapons as well as semi-automatic weapons with large magazines/clips. If we can make that happen, let's leave it at that for a while and see how it goes before going any further.
Reach out to friends, family, and co-workers that are going through hard times for any reason. If there's someone you feel is disturbed or unstable and in a position to do serious harm then make a strong effort to alert anyone that can help.
Be kind, selfless, and accepting of others in the real world AND on online. Stop jumping to conclusions, stop shit posting, stop grouping up on someone that said something stupid, etc.
Just remember that terrorism is here to stay for a very long time. Mass shooting/killings (of varying scales) are here to stay. They've always been happening and the only surprise is that these kinds of things didn't happen sooner. There are dark times ahead. America is filled with people living in fear of change, race, and religion but that doesn't mean you can't make a difference. Just make sure that when you're trying to make the world a better place you do your research (from multiple sources) to make sure you've got your facts straight and don't leave your common sense and heart behind.