I'm not sure to which countries you are referring.
But in many countries around the world this problem is greatly reduced, if not eliminated only because these countries also have strict gun laws that stop this happening.
A police office in the US has to assume the perpetrator will be armed with a weapon and that then leads to the 'shoot first ask questions later' approach to policing.
Alternatively, places where guns are not so prevalent means that anxiety is greatly reduced.
As an example the majority of English police (i.e. bobbies) do their patrol work while not carrying a gun.