I would need to be convinced about the capabilities of the individual before arming them in this setting.
I retired in 2011 from teaching technical subjects at a big city high school with 3K+ students. There were several rival gangs from different housing projects, and 10+ acres under the roof on 3 floors. Two full time cops on campus, plus a couple of juvenile probation officers to keep tabs on some of the really hardcore gangbangers. The admimistrators were probably aware that some of us, mostly military veterans, carried on the job, but they, and the cops developed selective blindness about the situation. It was impossible for the SROs to cover the entire building when it might take 5 minutes or more at full gallop to get from one place to another.