To your philosophical quandary, though, you might take a look at Robert M. Persig’s Zen and the Art of Motorcycle Maintenance (or it might have been in the follow-up Lila). Therein Persig argues that there is no such thing as insanity. When you have a person that doesn’t fit in with society, the solution, he suggests, is not to kill them, or to change them, but to change their society. Perhaps someone that’s sexually-charged all the time, to the extent that they commit crimes, might fit in better in a place like pre-industrialized Samoa, where people became sexually active before puberty, and were encouraged to have as many sexual partners as possible before they got married, so they could see who they worked best with.

The idea is probably impractical, but it’s worth looking at.