Maybe we can enact some that make it safer for the law abiding gun owner and slow maybe some of the gun violence and mishaps down?  I was thinking a gun owner certification card that a person would have to apply for, test for, and renew every year.  Maybe even include an annual psychological eval?  Get caught with a gun and without that card, and 25 years in jail.  Commit a crime with a gun and it's life.  All private sales would require the seller to check the buyer's card and maybe even log the sale through a database with the gun owner cert numbers involved.  Might help kill off the black market in large part or sales to the wrong guy. And, with repeated training and testing, maybe it'll clean up some of the accidents around the home?  Training doesn't hurt anyone. 

No, it wouldn't likely have stopped this guy, especially since the military swung and missed on this.  And, it won't stop everything.  But might make it better for many.

BTW, I'm a gun owner.