Originally posted by: Jeff7
My physics teacher in high school was talking about how we'd have bomb scares, and how difficult it would really be to totally sweep a school of bombs. He had two ideas for bombs too, placed in the drop ceiling. They'd either have accelerometers (someone lifts up the panel to peek around) or IR motion sensors (someone lifts up an adjacent panel). Building and placing bombs is just so easy if you're careful and smart about it. But that's the fortunate thing - many criminals are quite stupid, or else they want glory, so they leave calling cards that tend to lead to their arrest. I've always said, the perfect serial killer is someone who is intelligent and selfless. Such a person would be virtually unstoppable. Don't leave a pattern, don't leave evidence, don't leave calling cards. Fortunately, most people don't do that.