Unfortunately, once again, a "good guy" with a gun was required to end the evil actions of a "bad guy" with a gun. While the vast majority of the world is comprised of good people, there will always be that very small number of people who are pure evil and will victimize others until stopped by a deadly use of force. These evil people are always able to obtain a firearm since they don't care about following enacted firearms laws. The other really sad part of this tragedy is that there was an insufficient number of law enforcement officers available to immediately deal with the gunman. As we saw in Texas during 2 church shootings there, an armed citizen ended the violence before the police could arrive on scene.