Phazers Set To Flashy

The door sensors in the library here at school keep getting set off by students lugging their laptops and notebooks in and out, or because their radioactive metallicized books weren't desensored properly. The alarm sounds like some sort of space death-ray. I can't see the doors or their sensors from where I'm sitting, but everytime I hear the alarm go off, I picture that the poor student trying to pass through is immediately pinpointed by lasers and vapourized in a flash of eerie green light, a "deer-caught-in-headlights" expression as the last to cross their faces. Poor souls, and all they wanted to do was learn.