My g/f's younger sister has Down Syndrome, and I can't imagine anyone being so inhumane that they would think the best way to keep her in line would be electrocution. This is the sort of thing that should have been phased out in the early 20th century when people were starting to realize that disabled people were, in fact, people too, and they weren't as inherently dangerous as any other person.
Both from her and from working in the school district (I've interned a few times with occupational therapists and as a teacher's aide in classes for cognitively disabled children), I know that many disabled kids honestly can't help themselves. Half the parents are incredibly overbearing and treat their teenaged children like toddlers; 3/4 of the remaining parents seem to have already emotionally disowned their kid. In either situation, this kid is not in a nurturing environment that would allow them to work through their disability, they're generally looked down upon and abused by other kids (and their own parents), and since the educational system in America values its worth based on test scores, jobs as occupational therapists and e.d/c.d teachers are 90% staffed by people who don't give a shit and can't get work anywhere else, 5% by people who care but really shouldn't have their job (because they're incompetent) and 5% by people who actually care about their job and the kids and do it well. It's a pretty sad situation that most disabled children are treated like dangerously psychotic patients and criminals in a hospital, because, no matter what people say, most of them are aware enough to know they deserve better.