I would encourage someone to report as soon as possible
I would definitely follow the law. I understand these things or anything related to sexual violence is an offence, but hiding it is also an offence. If your friend comes to you for help or to share their assault, I would engage that person to report the violence to the authority. It cannot be tolerated. There is no option just to take things inside. Someone should be punished, and we should abide by the law. I would encourage someone to report that as soon as possible.