Safety policies designed to protect schools from mass shootings have done little to deter them and may even be harmful to students, research shows, despite a renewed push for such measures in the wake of Tuesday’s shooting in Texas.
The 18-year-old gunman who killed at least 19 children and two teachers at a Uvalde elementary school was able to evade armed police officers and other security protocols already in place. Yet some U.S. lawmakers are arguing those policies are needed, and…