wireless locator

I saw recently a program that will use a metering GUI to show the proximity of other wireless computers that are attached to a access point. Does anyone know where I can find something like this. My problem is simple, 2 laptops have recently been stolen form the local school district and the Perps are logging into the school at night. I’ve been asked to see if there is a way to locate the proximity (house) that the connection is comming from.