I'm genuinely asking this out of curiosity & confusion. I've heard school shootings happen in America where the shooter is actually a student that attends that school. I also think everyone at the school learns what to do when there's an active shooter present and which drill/routine to follow so, that also means that the shooter knows that exact routine and therefore knows where to go to, to find the students etc. right? Doesn't that make following that routine very unsafe? I guess the school doesn't know beforehand if the shooter is a student that attends the school or not but I want to know if this gets accounted for or not. I'm just a bit confused (and uneducated) about the whole thing so, can someone please explain how this works?