<p>I read in the university’s online newspaper that this happened during Beer Bike, when it’s not unusual to have non-students on campus, so people would not necessarily have thought twice about a stranger entering a dorm behind them, etc. They managed to track him down in part because he initially swiped his old student ID in an effort to enter the dorm(s), but it had been disabled when he graduated, so it would not open the doors. Definitely can happen anywhere (wackos are everywhere), and definitely alarming. A good reminder that it pays to exercise caution no matter how safe you think you may be.</p>