TGUNTER's son won his debate earlier this year. The thread had a number of sources that, while not exactly the same topic, may help with some of the more general arguments for having a gun at all, leaving just the "on campus" part up to you.
http://ingunowners.com/forums/genera...a_handgun.html
Also, IMHO, statistics don't win debates. They are necessary and good anchors to keep your argument solid, but telling the story of why your position benefits your judge/audience/opponent etc is just as important.