What should I do, I just found out my 15 year old daughter was raped two years ago by a minor?

If the boy's family has money, or even might, then lets discuss a civil suit. Sooner the better as statute of limitations on personal injury cases can run quick. If they own a house, they might have insurance to go after. If this happened at school or another place where you thought she would be safe, we might be able to go after them. This money can help your daughter get the help she will need. It won't make up for the suffering, but maybe it will help her see justice. The police will conduct an investigation. Your daughter will need support and therapy. The police and DA will help you find where to get that. If you feel like the police or DA are not helping, a lawyer can help. You might look on-line for rape survivor information so that you can learn how best to help your daughter. Anger will not help her. The boy is not your problem. Just take care of your daughter.