Sidwell Friends school (where the Obama girls attend) have 11 armed guards whether or not the girls are there. The Secret Service personnl are over and above those eleven. I doubt that many other private schools of that size have that many (if any) such personnel. Do your kids have eleven armed men keeping the bad guys away?
Well my kids are grown. But while they were in school there was a Resource Officer on school grounds every day.
I believe the uniformed armed policeman/woman was there to keep the kids in line (more or less).
At least one of them that I knew personally seemed to spend most of his time doing just that.
It is a small school district about 900 students K-12, all on one campus on which all of the building connect.
A determined killer who knew the layout intimately could undoubtedly kill a good number of children and staff before the officer could stop him especially if he stayed on the move.
Having only one officer on the campus is insufficient for a school of any normal size.