I am sorry for what you are going through . As you say, he's safer there, for sure.
Demanding money for bail sounds like he really needs his head to clear. His actions put him there, and you do not owe him .
If you can, step back and get your mind clear as well. What would you tell your best friend to do, if it was her son?
He is safer there, and needs rehab . Sounds like a ticking time bomb.
Be strong. Keep posting. Others have surely been where you are.
prayers for you and your son.