Be there and instantly engage the shooter. The number one factor to limit injuries and fatalities is to engage the shooter as quickly as possible. This turns what was planned to be a shooting gallery by the shooter into a gun fight. And they do not want gunfights. They often will end their owns lives when confronted by resistance. In this case Eli Dicken engaged the shooter and the threat was over in 15 seconds. Unfortunately the killer had killed three in that time frame.
