We in the US are in a safety trough between bimodal points of perceived "safety" -- 100% civilian gun ownership ban (like Japan) and 100% civilian gun ownership (like Kennesaw, Georgia). The point we are in now is naturally unstable. People lack the training to know where a shot comes from and what to do (contrast this with the situation in 1963, when people were hitting the deck the moment they heard a shot, and afterwards knew where it came from, near the Grassy Knoll in Dallas). Of course, the far better stable point is everyone owning and familiar with guns.
To all this I would consider adding, in this case, possessing and willing to use a bulletproof vest.
I'm not old enough to have a personal memory, but I do recall hearing that pedestrains ran and got their rifles when the guy was sniping from the Tower in Austin.