You mean, they'll go to a playground or church instead? After all, "additional protection" implies there is some other area with less protection. If we have an armed guard on every street corner, there is no additional protection.
Thank you, Syndrome. (https://www.youtube.com/watch?v=A8I9pYCl9AQ)
So you're saying that shooting incidents are a "zero sum" equation? That having guards at Newtown would have simply resulted in a shooting elsewhere that day? Remember, this wasn't a randomly chosen location.