You Y-O-U are your own ‘first responder’.
You Y-O-U are the only one that you can depend on to defend yourself.
No Policeman, or any other Law Enforcement officer, in fact any of the school staff -by Supreme Court decisions Deshaney v. Winnebago County and Castle Rock v. Gonzales – have any responsibility, or are required, to do ANYTHING to defend, protect, or save you or your children who still happen to attend public schools.

No Law Enforcement doctrinal change makes one bit of difference. If some officers happen to do the ‘right thing’ and immediately advance on an active shooter and take him out, all to the good. But there’s nothing, besides an officer’s internal morality and sense of personal duty, that can make them do anything other than make sure they’ve used some hand sanitizer.