WIBTAH if I exposed someone's private trauma in order to protect others?

Throwaway for obvious reasons.

We grew up in a small community, with a large powerful family that pretty much dominated everyone's social life. The patriarch is a known asshole, but everyone put up with him bc he is wealthy and well-connected, but otherwise not thought to be an evil man. He has many kids, three of whom are involved in the current shit.

One of his sons (m/mid 20s) is a pedophile. We recently discovered this while speaking to one of his victims, who is also his younger sister (f/late teens). Another female relative (f/mid 20s) has also told us she was a victim in childhood, and confirmed the sister's story. These events happened when both girls were between 6-10yos, and the boy was 10-13yos. There was said to be a third girl, but she was never part of our community and we cannot confirm her story. Another sister (f/early 30s) discovered this a few years ago, and informed one of us, who kept it private due to an inability to confirm the information. It was revealed by this same sister that the father knew about the crimes, and helped cover it up and keep it private. Now that we have heard from 3 people about these actions, we are faced with a crossroad.

We have screenshots, texts, and three sources. However, all three sources will likely refuse to say anything out of fear of the father, who is a powerful man with many connections. We who have been told are not afraid of this man, but as we are also young, we don't know what we can do to help. We are worried if we expose the pedo, we put the victims in a position that will retraumatize and follow them. The sister (f/late teens), still lives with the parents, although the pedophile has moved out. We are worried if we don't say anything, he will victimize others. The pedophile holds a position of authority in a teen camp organization. We have no one else to run this by as we the writers have been discussing this amongst ourselves for quite some time now.

We don't know what to do. Would we be the assholes if we spoke to an authority or one of our parents about this?