Does he have services for somebody who is intellectually challenged? I'm not so sure I'd abandon even an adult child if he had such limited potential. I know that for my autistic son I made sure he had adult services ready to take him once he graduated from high school. I don't consider an intellectually disabled child the same as a child with an average IQ who is capable of doing better and just chooses not to. There ARE some people who DO need help, even as adults. How will it help him to be in jail? Is he naive? Will he be victimized?
Although I was tough on my difficult children, both were highly intelligent. This to me is different. Why isn't he getting state help? Does he have a caseworker and job services? I won't sugar coat it. An IQ of 65 used to be called mentally retarded...we don't use that term anymore. I understand why. It is demeaning and I do not mean to demean your son. But he may not know how to cope any better than he is. He should be getting Disability and healthcare and other adult services comes with that. I would want a lawyer who would argue that he needs help, not punishment. My difficult child, who is 36, is bright, street smart, and would survive jail, even if he wouldn't like it. But I don't think your son will deal well with it, just like my autistic son would be everyone's victim...
Please get him the help he needs. He is more like a child than an adult.And, trust me. I am a huge believer in tough love, but not if an adult child has a disability that truly makes him unable to survive with others helping him and I am guessing your son fits into that category.
Good luck, whatever you decide to do.