When I moved into our first house the day after we moved in someone went down the block and punctured the tires of about every fourth or fifth car, some of them puncturing more than one tire so you couldn't just use your spare. My car got hit but only one tire. It was a sad sight seeing everyone heading out to work and standing out there scratching their heads. Welcome to the neighborhood!
Sometimes people just do nasty things because they can get away with it and it makes them feel powerful. Hope you get it resolved soon.