Last I heard from a BCSO friend they get dispatched by them after 5 pm and during the day they have a separate channel they use for dispatch. So they have moved to the Provoice system at some point. Like most school districts have in the county.
I did a search on the FCC ULS site and turned this up. they may be using one of these frequencies during the day, but I am not sure how far it will go as the license shows that all the channels are mobile only with a 3 km operating radius. Seeing as all the schools are clustered fairly close to one another there really isn't a need for a repeater.