Legal Question in Real Estate Law in Maryland

Upon notification of your mother's death, the lender will call the loan, meaning her estate (assuming she was alone on the deed). Therefore the property will have to be sold or there will be a foreclosure. Depending on how fast the lender operates, this could take months. Once the foreclosure is finalized, the purchaser will evict him.

If there is enough equity in the property to yield proceeds to the estate after the lender is paid off, it is the duty of whoever becomes executor (personal representative) of your mother's estate, either by appointment in her Will or by the probate court if she didn't have one (a family member, such as yourself), to protect the value of the property. It sounds like there is real potential for a deterioration in value based upon the current occupancy status. If your son continues to refuse to leave (and why wouldn't he, it's free housing), you may have to take him to court by filing a wrongful detainer action seeking eviction.