When the police get there they need to move fast. Anything you can do to facilitate that would be a good idea. Communication is also important. It's important for everyone at the police department, not just one or two guys, to know what you're going to do in the event of an emergency. Various plans call for teachers to have an emergency backpack or briefcase in the classrooms that they can grab and go. Ideally there would be a gun in there in my perfect world, but that's not going to happen. Other stuff would be first aid supplies, emergency contact info. for each kid who could potentially be in the class all day, etc. Also, if a room is locked and secure, someone can arrange a predetermined signal to let the cops known so they don't waste time on that room. Something they can see as they're running down the hall. Stakeholders should probably meet at least quarterly to share ideas and notes.