Obviously you can not stop all gun violence. But, we are among the worst in the world in gun deaths. Maybe looking at why other countries have fewer deaths, by huge percentages, may be of help in deciding what could be done here. Saying that nothing could have been done is simply the same statement used over and over by the gun rights nuts.
Let's look at Switzerland.
snopes.com: Gun Ownership in Switzerland
I would have no problem with that...tied with manditory military service as they have.
I doubt that because the court has ruled
"all males physically capable of acting in concert for the common defense" and that "when called for service these men were expected to appear bearing arms supplied by themselves and of the kind in common use at the time."