First of all, welcome aboard the Banana Express.
There have been some good suggestions mentioned, as far as getting your money back, but there are three that will get the best results:
#1) Contact your state Attorney General's office. Since this involved a school, this should be a state matter. Depending on where the money originated, it could also be a federal matter. The trouble with the latter, is that in order for the FBI to investigate a fraud, it has to exceed $1 million and I doubt your grant came anywhere close to that. NOW, if you have evidence that this guy is involved with some sort of domestic terror or drug ops, then PM me the details and I can notify the JTTF directly on your behalf. Other than that, the Feds are out.
#2) Contact your local TV stations and get them to do an expose on the guy. This will help to expedite what the authorities are doing, as well as embarrassing the responsible party(ies) quite publicly. He will lose all credibility in the industry, as well as still possibly being charged criminally.
#3) In the meantime, file a suit in Small Claims court.
Between the three, you should recover your money. The guy just needs a little pressure, and I guarantee you that #'s 2 and 3 will be quite effective.