Minors that need to be protected. It may be too late for criminal penalties for the parents, but what about Child Protective Services?
The adult criminals here are the mother and father, who knew about the molestation and did not report it. They were the ones responsible for what occurred and for handling it. So Josh is now having to live through the results not only of his actions as a minor, but his parents' actions at the time. They should have reported Josh at the time. But once you start hiding your crimes, your life is eaten from the inside out from the lies of omission as well as those of commission. Why did the Duggars agree to expose their family on tv? They are in such deep denial that they couldn't even see the risk they were taking.*
In that sense, Josh is a victim here, too: of his parent's beliefs and actions just as his sisters are.
*The Greeks have a word for it: hubris. See Oedipus Rex.