Gee, I guess we haven't figured out that shootings occur at victim disarmement zones.
And as usual, the shooter committed suicide.
So how do you stop somebody who is intent on committing suicide from taking others with him? How about denying him easy targets.
You may even save the shooters life. If your eating your gun, the success rate for a fatal shot is really high. Whereas, if somebody else takes down the shooter, there is a good possibility of the shooter surviving.
Of course, I believe that all human life is sacred. The use of lethal force is perfectly justified when people's lives are in imminent danger. The moment the threat is neutralized, the use of lethal force is no longer justified.