change the laws so that regular people cannot own a gun and implement higher security standards in public places.

It is a fact, the United States of America, a nation that probably thinks of itself as a "first-world-country", is a dangerous place to be, for the fact that so many regular people are armed. The thoughts of personal "freedom" cost many victims.
But today, there are many people in the United States who have a different opinion. They know: where there are no guns, no guns can be fired. This sentence is always right, no matter how complicated the issue might be. Regular people shouldn't own a gun.
Still, a shooting could happen any day, anywhere, in any country. That's also a fact. The only thing a good community can do about it is to reduce that risk. One step: Regular people shouldn't own a gun. Another step: Public places, like schools, should be stronger protected by security measures.