The article mentions that the school district also owns "10 police cruisers", so apparently they're responsible for running their own police department for some reason (which is real-life weirdness of its own). Government works in mysterious ways.
The military is basically giving MRAPs away because they don't need most of them any more as Iraq and Afghanistan wind down; they're keeping about a third of them. Remember all the articles a while back with pundits indignant that they were scrapping billions of dollars worth of vehicles? Now people are indignant that some of them found another use rather than getting scrapped.
Might not be a bargain even at scrap prices because there's still the operational costs to consider. But if you think you have a need for a truck, it might not be such a terrible idea to start with a $5000 demilitarized MRAP than a $50,000 commercial Ford Expedition or $131,600 for a
used fire rescue truck.