Disposed of my own belongings? Theft or negligent? What can I legally do to have him not use my stuffs?

Due to the confrontations between us, my roommate intentionally disposed of my personal belongings, which cannot be found anywhere at the moment. Is he liable to the things that I lost? What kind of a case is this supposed to be? And what the differences here are, should he plead it was by mistake? Would I report to the police in case of such incidents in the future? I officially asked him not to touch and use my stuffs but it does not help, and everything is vulnerable. Can I legally get him not to use my stuffs in order to be on the safer side?