In my opinion, this is how people should be reacting to this tragedy. And thankfully, a good portion of people are.
The media, however, is a different story altogether.
Already they've begun tearing into this incident by using their platforms to create more mass hysteria by means of repeating the same old, tired arguments -- debating about gun control laws, certain politicians twisting everything for religious propaganda, blaming video games/television/movies/etc, arguing about the TDK franchise and whether it's also to blame, the entire genre and its political messages, etc. Every time a tragedy like this occurs these debates keep getting recycled over and over again, with very little development on the real reason behind the incident. I know we all want to know why this happened, we all want answers and to make sense of it. But the media always turns into a circus by feeding into this ridiculous mass hysteria which is precisely what this terrorist fucker wants. Instead, they should be talking about the victims and the survivors. Focus on their stories, not the killer. By giving into that fear and hysteria, he will have won. Don't give him that power. Give the power to the victims, the survivors, those he affected so they can take back what he took away from them.
Obviously this investigation is still going on, and will be keeping tabs on official reports and statements made in the coming days. It's all very tragic and devastating, and has hit an emotional nerve in all of us. And hopefully, by the end of it all, justice will rightfully be served.