The following is a sevora regarding reporting the perpetrator even against the wishes of a victim or others. I have not seen this reasoning anywhere so it is possible that it is wrong. I would appreciate comments and suggestions
While we have a clear rule that we don’t sacrifice the life of one person to save to save other people there is a clear exception in the case of rodef. A rodef is killed in order to prevent him from killing or raping. There seems to be a second exception in regards to the relative importance of the spiritual well‑being of the rodef versus the life of the victim. The rodef’s spiritual well-being results from being prevented from sinning. Sanhedrin(73a) asks what if the woman that is being pursued to be raped - tells her rescuers to leave the rapist alone because she is afraid the rapist will kill her. There is a dispute in the gemora regarding this point. R’ Yehuda says she is to be listened to because she values her life more than her honor. We posken like the Rabbis (Shulchan Aruch C.M. 425:4) who says we don’t listen to her because the Torah is concerned that she shouldn’t be raped. In other words our prime goal is to stop the rodef from sinning – even if it means the victim is harmed.
It would seem that we could generalize from this that even if the victim or her family say that they don’t want the perpetrator reported because they are afraid of the damage to their reputation – the perpetrator should still be reported. That is because the perpetrator is likely to abuse others and therefore still has the status of rodef after the molestation. Consequently even if the reputation or even the life of a victim is lost – the rodef has to be stopped. Thus it seems we have a second exception to the principle of not sacrificing one person for another. The life or reputation of a victim is not as important as stopping someone who will commit rape or murder in the future - on an unknown number of other victims. This case is even stronger because here the victim is saying not to stop the rodef from harming others because she will be embarrassed, while in the gemora she is saying not to stop the rodef from harming her. Thus she has less authority than in the case of the gemora and therefore the perpetrator should be reported.