I'm sorry this occurred.
If you want the university to help, you may have to show them how you could cause this to become bad publicity for the university. If nothing else will get them to pay attention, the notion of protecting their image will. Everything that you posted about this within your first post needs to be taken above the heads of the campus police. Contact your local media, and mention to your campus that you have done so. Do not be directly threatening, but you should not waver from your stance. Also it is very important that you follow through with any actions that you state you will take. Demonstrate that under no uncertain terms, that this crime will reflect poorly upon the university.