<human>: I am not sure if this is the best place to post this but I will give it a shot.

So to start from the beginning, My father owns an apartment unit and rents it month to month. On Saturday night the tenant called that they have already moved out all of their belongings and were officially moving out Monday (1/11/16). I do not know much about the legal side of this but, they did not bother giving us proper notice on moving out. She moved in a few years ago on a fixed lease for 1 year, and after that my father never bothered to renew the lease. From what I know, In the state of California if a landlord does not renew a lease, it automatically moves to a periodic tenancy agreement. This was all done verbally and have no documents of this month to month agreement (payment on the 5th). From what I read a periodic tenancy agreement requires proper notice of equal duration of a payment (1 month). So my father had a meeting with them and they responded that since they were month to month then they did not need to give a proper notice. They even threatened to bring in a lawyer.

Also they did not even bother taking care of the apartment. There are broken doors inside, writings on the wall, carpet is damaged beyond repair, and a disgusting odor around the kitchen. 

So my question is if they have any legal right to move out without giving a notice. 
If They don't have any legal right to do this, what would be our next steps to handle this situation.
If they can, what can we do to minimize our loses. 

Any help would be greatly appreciated 

Link:

[Here](

Can you give me the gist of the text in a nutshell?
<bot>: Tenant gave a one day notice of moving out from an apartment on a periodic tenancy agreement (month to month) in California