Hi MarTer,

to the states and to PC! Congratulations on your soon-to-be parenthood too. Wow! Lots going on for you and your wife.
There are group homes, aimed towards helping those with disabilities. I would advise you to look into the local county programs with homes like those. Not that they should be locked up, I don't believe in that at all! However, I do believe that they need a little more structure for their safety.
Residents of these group homes can work part-time, they have their own bedroom, take their own showers, etc. But, a professional is there to see that they take their meds, talk when they need it, organize activities that residents may or may not want to participate in. That's what I'd advise for your BIL.
Look online, in your state, and surrounding county (or counties) to see what is available.
Very best wishes to you and your family!