dose your colledge have a law school? if so you might inquire there and it might not cost you anything to be represented. sounds like they have no evidence. wrong place wrong time. what dose your roomate have to say?
the bad thing is most colleges require you to stay in the dorm for at least a couple of semesters and they pick who you stay with, then, this happens and you have a strike against you.
the zero tolerence is BS.