Hey, solana, welcome to PsychCentral.

Wow, that's really hard. I don't think he can be around where he's endangering your mother's and husband's health (stealing the meds they need; one can't get "more" that easily!)

I'd put him on alert that he's out the door by X date and to get a job and lock up all the drugs inbetween. Don't do laundry or other personal services for him or let him use all the dishes without washing any and eat you out of house and home either, make him as "uncomfortable" as you can!