But in reality a lot of junior and senior high schools become packed like sardines between and before classes. How quick can an adult teacher get through panic teens running in the opposite direction? Even if you had a gun unless you are point blank with him how can you fire a shot without taking out an innocent student.
But an adult teacher did take him out so it is hard to predict how many more could have been knifed if not for the fast thinking teacher.
Unfortunately we will see this again.