Create a federal law that mandates schools K-12 with more than 200 students have a minimum number of armed security guards and/or police/peace officers. Schools with less than 200 students shall have gun shot detection devices that alert law enforcement.
Armed units, hereby defined as any person working in a K-12 school in a security/law enforcement capacity authorized to carry firearms.
The minimum number of armed units will be 1 armed unit per 200 students. But not less than 2. But not more than 8.
States will have the discretion on uniform and open/conceal carry armed units. Except that all armed units will be fitted with firearm, less than lethal options (pepper gel, baton, taser, etc), inner outter body armor.