We can’t even doagood enough job of screening teachers. Every year, we learn about (mostly female) teachers sleeping with students. We can’t screen Army psychiatrists. (Remember Ft. Hood?) We can’t screen cops. Lots of controversial shootings of unarmed people by cops every year. (They nearly always get off.) All it takes isafew bad choices of armed school guards, and the fox is right in the hen house. Not worth it.