Does a parent have the right to send their children to school without fearing for their safety?
The answer to your question would be dependent upon how a society chooses to conduct itself.
You are afraid of possible criminal incident. We know that - "if left to itself" -
it will certainly happen if we allow it to occur.
If you really want to keep your children safe at school:
1)
See to it that
every person elected, appointed, and hired to oversee your children are good honest moral people who will
personally take it upon themselves to protect your children at any-and-all cost to themselves.
If your children are not surrounded by these kind of people at school - their safety has already been compromised.
2)
Make sure that they are well-armed and well-trained with their weapon of choice.
This is
not to say that it should be mandatory for each person on a school staff to be armed. This is, and has to be, strictly on a volunteer basis.
How many people would be foolish enough to walk into such a school with the intend to do harm - accepting the risk of being shot multiple times by armed school staff - possibly even before they could begin to inflict that harm?
If you want to avoid all of this, there are two options:
1)
See to it that
every citizen is a good honest moral upstanding God-fearing Christian strong in his/her faith.
2) Homeschooling
(Now you know why homeschooling is such a popular solution.)