I'm definitely in agreement here that there is that threshold, but what I'm not so clear about is where that threshold lies. It's one of those things which I feel the boundary is nothing but grey. However, one area where I think might be relatively easy would be the case of crime + health. Rather than jail, forcible internment in said mental health facility might be a better alternative.

On an aside, it's funny how "One flew over the cuckoo's nest" had such an impact on mental health treatment, and how mental health institutions were viewed.