Addicts generally need to hit their bottom before they clean up. If you pull him out too early you could be setting him for more years of using, which he may not survive.
My sister and I left my alcoholic dad in jail for 5 months so he’d clean up and he did. It sometimes isn’t nice but addictions need a special type of love.
I would write to him bc some of the biggest joys an inmate has is when they get a letter. Otherwise it’s probably better for him and you guys if he stays in. He could get on a work program if he behaves himself.
I honestly have no idea what I would do. That’s a really tough call, and it seems like there are only bad options. Jail sucks. Releasing him onto the streets sucks. Both could end with him in better or worse shape, and there’s really no way to know which it would be.
The way I have approached my recovery in life has been by constantly trying new things. When something doesn’t work, I try something else. It sounds like you’ve already tried giving him a place to stay, sending him to rehab, letting him live his own life, and lots of other options that would definitely be more humane and compassionate. Has he ever stayed in jail before? I know it can go badly for a lot of people, but it can sometimes be the catalyst for growth. Ultimately, he will keep using until either he dies, or he decides his life is worth fighting for. Different people learn that lesson in different ways.
Sorry you have to handle this decision. It is a lot to weigh on your mind.