I rented out a room to someone in my condo that I also resided in, in California. She vacated one night at 1:30 in the morning, but did not give written notice or return the keys. She also stole my car that night on her way out (but that's a separate issue to the security deposit and she did leave it on the street out front a week later, she was likely on drugs). About 2 weeks later I did get the keys back from her mother who came down from England to visit her daughter/my ex tenant in the psych ward. I do not have a forwarding address for my ex tenant, other than her mother's address in England, although she does not live with her mother. After 30 days from not hearing from her she called me on the phone to ask for her deposit. Granted it doesn't feel right to return her deposit after the hell she put me through, but I don't want to do anything that could give her reason to sue me. My question is this, it states in writing on the month to month tenancy agreement that she must give 30 days "written notice," but she did not give any written notice, and she didn't return the keys until two weeks later. Does not giving written notice forfeit her deposit? Or do I still return the deposit prorating the days until when I received the keys back? Or is it from the date she left despite not having the keys returned? A bit confused on this particular situation.