NG - Because the question is about a second party (elders) reporting. But regardless of whether it is mandatory or not, the victim/parents are free to report it whenever they want. Obviously.
Obviously, you are either the most intellectually dishonest person I have come into contact with in some time, or the most naive, I am really not sure which. I will give you the benefit of the doubt that it is the latter, so I will enlighten you a bit...
IF the parents either go to the police first, or go after the elders have determined no two witnesses to the crime exist to allow for a JC, the parents will be DF for either "causing divisions", "slander", or some other such catch-all type infringement. If not actually DF, the parents will be put through hell by the elder body, and essentially forced out of the congregation to save face. This is a regular occurrence in almost every congregation, and is the entire root of the problem. The policies the organization holds to are designed to protect the organization at all costs, (human or otherwise). The policies are neither moral nor do they ultimately exist for the benefit of the congregation members. When it comes to the organization's interests vs. that of the well being of its human members, the organization wins every time. Believe it.
Yes, the 7 men leading this mess in Brooklyn are both stupid and evil.
d4g