My daughter has POA over her grandmother and my daughter's father got out of prison and knew his mother had alz. and my daughter had POA to get money for his drug habit he talked his mother into selling one of her houses and now they say nothing can be done because the people said she signed the papers even though they were told within a month of the deal that she couldn't sign anything that her mind was not right. they were provided with a copy of the POA
At the very least it sounds like Father has exploited his vulnerable mother. That is a criminal offense.
(Isn't drug addiction a sad tragedy?)
Who is the "they" who say nothing can be done?
If you want this to stop, you & your daughter either need to press charges on him, contact his probation officer or have a court order for him to stay away