A Practical Solution

No single action will prevent mass shootings. Stricter laws against gun ownership will not prevent a gun massacre because the type of person who would carry out such a crime would have no compunction about violating any restrictions passed on the purchase or ownership of a firearm. One thing that would curtail these atrocities would be permitting law-abiding gun owners to bring their concealed weapons into places of worship or schools, so that the potential gunman would never know who might be able to oppose him with equal force if he tries to gun down parishioners or students and school staff. The element of doubt would be introduced into the minds of potential mass murderers because they would never know who or how many might shoot back. Gun-free zones are full of easy targets.