Regarding teachers with guns. This came up recently at a meeting I attended. The concern is, when LEO enters, has this video shows they are ready to shoot. A teacher even though trained may be in the wrong place at the wrong time. It's very difficult to make a split second decision when going in to save children and an armed plain clothes person steps out armed. The killer could step out and yell I'm a teacher,, then shoot them in the back has they go by.