So glad you asked.
It is always hard to talk about specific incidents and I'm not sure it is the best policy to react to specific incidents. But hey, most of us take our shoes off at the airport now!
When you look at it from a broader perspective, the most effective way to reduce gun violence is to have background checks for all gun sales, including private gun sales arranged through the internet or at gun shows. Data shows (and we actually have this because there are about 20 states and DC that have these laws) that background checks for all gun sales reduce gun deaths by up to 50% across the board. This includes suicides, which in many states account for more than half of gun deaths. It includes domestic violence related shootings and it includes officer involved shootings. Would background checks stop every shooting? No, but they have proven hugely effective.
There are lots of other smaller things we can do around permitting and training requirements that also show positive impact.
We can also try to get rid of bad laws like Stand Your Ground laws and Permitless Carry laws which show an uptick in gun deaths.
Or we can do nothing. Offer thoughts. Offer prayers. And keep reading about individual incidents that when added together become a scourge on our nation. We really don't have to live this way. But we choose to do so.