Hi Everyone!

Here's the mess I'm currently helping my husband and his mother with:

Mom, Rose, owns a lot in Pasadena CA that has 2 single houses. Rose lives in one house and her sister, Susan, in the other. Rose was renting to Susan on a M2M. Susan allowed her adult son, Roy, to stay with her sporadically (4 months in Pasadena, 8 months elsewhere). Roy threw Susan out of the house she was renting on September 4th 2021. Since then, Susan has been staying with one of her sisters. Since then, Susan and her sisters have made 3 trips back to the house and have removed most of Susan's personal items.  

- Susan has not given notice that she has moved out
- Her adult son is still at the property - he is unstable and verbally abusive
- The police won't do anything because Susan will not file an abuse complaint against her son Roy
- Susan has not maintained the house appropriately meaning there are holes in doors, broken cabinets, damaged floors. There is trash inside and outside of the house (we have photos)
-We need to sell both houses ASAP because Rose is under 24/7 homecare due to blindness and other health conditions that do not allow her safely live on her own; she is paying for this care out of her savings and money runs out in December 2021.
-Our potential realtor has stated that because of the condition on the house where Susan lived is in such deplorable condition she cannot sell the property
-Our immediate goal is to get Roy out! (We cannot evict on No Rent Paid, although no rent has been paid since July - not due to Covid, just spite)
-Looking for suggestions - 
        Can we serve a 3 days nuisance/waste order to quit?
        Do mediators work in such cases?
        Anyone have experience with cash for keys (anything to get Roy out)
        The property is going to be sold, is this a reason we can get Roy out?

Any and all suggestions welcome. Good Grief!