I wrote and article a few years ago, Get in the Fight, in which I talked about citizens having a responsibility to their respective community. Seeing the above video and hearing that a citizen got his rifle up and got in the fight before any LEO was able to get on scene should be very inspiring. This man who is being interviewed here did not hesitate for a split second and got in the fight as well, putting the responsibility he has to his community first, before his safety with a total stranger to give chase and get in the fight.
Remember that regardless of what bullshit you may read online about types of firearms and possible legal issues, these two men did the right thing. They did not hesitate to get into the fight and they were able to stop the murderous rampage.
Get training, always carry, think critically and get in the fight when the time comes.