Sad events such as this are almost everyday occurrences in the USA.  When will they realize that guns don't kill.  It is people with guns that kill and guns without ammunition are next to useless.  Put a strict control over ammunition sales and there may be a solution.  It is too late for gun controls as there are about 3 guns in circulation for each American over 18.  The Genie is long out of the bottle on the guns.   Little hope here.  Perhaps ammunition controls may be a solution.