Having a very hard time processing this.
Firstly - if they are living off campus, what business is it of the University if they have a personal weapon? On campus can be argued, but off?
Secondly - Is the administration really this foolish? A student protects both himself and others and gets punished?
Thirdly - If they do get expelled, they had better be done so with both a clean record and the ability to transfer their credits to another institution. Also - a full refund of their tuition fees.
Look - I get the general idea that weapons in the hands of the young is a bad idea. Yet I have known 8 year olds I would trust with any weapon they could physically handle, and 50 year olds I wouldn't trust with a pen knife.