Urgent: need help with adult child staying in parents house

Location: Florida

I'm posting on behalf of my parents, who are elderly and are now at risk. My father is in bad health and his mind has started going, which doesn't fully excuse that he allowed my brother, 44, to move back into the house literally the day after a restraining order expired that kept my brother away until his child turned 18, who he was charged for sexually abusing. The child was adopted by my parents previously and has been living in the house since, and still lives there.

I need to know what the legal options are to get my brother out of the house. My dad allowed him in and my mom did not want it but is a pushover. Can she file an unlawful detainer?

My brother has severe mental illness and has physically abused my dad in the past, as well as verbally abuses my mom. Now he's running the house and I live across the country, but need to do something. My mom won't leave because she cares for a feral cat colony in the backyard that relies on her. I don't know how to resolve anything from that angle so I'm hoping to get my brother out.

Bonus problem is that the child (18) also has severe mental illness and is incredibly unstable, but my mom has been unsuccessful in finding a home that will take a person with autism, DMDD, ODD, and has a history of violent outbursts.

I need to know what I can do as a person who doesn't live there, and also what my mom can legally do. She's stubborn about doing anything to help herself but I'm going to try.

Author: _canis_lupus_