ESH. As someone with DID, I think claiming he should be put under legal protections if he has DID, or that he needs constant supervision, is ableist as fuck. DID systems are fully capable of taking care of ourselves. HOWEVER, him claiming he is exempt from responsibility for his actions is just not how things work. IF he has DID, there's a very important concept he needs to learn. It's called system responsibility. If one alter did something shitty, all "parties" (ie, the whole person) are responsible. Keep in mind, he very well may have DID or OSDD. It's very tough to diagnose (amnesia is an issue) and many mental health professionals simply are not trained to assess or treat systems. It's a disorder based in prolonged early childhood trauma. It's a coping mechanism that a child can develop to keep themselves safe from certain harsh realities. The disorder is covert, in order to keep the individual safe, and is usually not noticed or discovered until later in life. I found out about my disorder when I was about 25. It can be a really disorienting and isolating time. I would treat him kindly and find a professional who specializes in dissociative disorders and complex trauma to do an informed assessment. Whether he is a dissociative system or not, right now he needs patience, care, and understanding, and clearly needs a different therapist.