This is, I think, the result of a general misapplication of government resources. We, as a community, are willing to fund policing, but not education - and that includes educating the educators. Because our spending priorities are skewed, the social costs are skewed. When you only hire carpenters every problem is a nail. We need more electricians.
And we fail to see the second- and third-order effects. Cops in schools means more arrests; more arrests, more convictions; more convictions, less employment; more poverty, more crime, more law enforcement. Rinse, repeat. Dumb budgeting.
Now, reverse the cycle: more education funding, less discipline required, better outcomes; better outcomes, more education, better graduation rates; more education, better wages; better wages, less poverty; less poverty, less crime, better economy; less crime, better economy, more funds available for other priorities (and tax cuts!).