You do realize that these 2 were in a supposedly civil place, not a war zone, right? How do you let 4 planes get overtaken by terrorists right in the middle of the normal morning flights?
You have any idea how much energy it takes to assume every person walking up to you wants to kill you? Are cops now to be expected to wonder if a kid walking up to them is wearing a suicide vest? That'd likely be the level of vigilence they'd need to not get ambushed.
Hopefully this doesn't get repeated, but if cops are now expecting the worst at all times, it won't improve community relations any. And there will be additional shootings by cops as the expected probability of the guy 'acting funny' being a lethal threat has now increased.