Any time a person has questions about criminal law and the criminal justice system, and does not want to start with the police or prosecutor's office, a good place to begin is with a brief consultation with a criminal defense lawyer. Many have been prosecutors earlier in their careers.
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Contact your local police department. They probably have a specialized detective that handles these types of case. He will investigate and determine whether charges should be filed.
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You say "years later", how old is your daughter now and what is her relationship with the father and their relationship with the child? If she is now an adult and has no interest in seeing a prosecution of the father, I think you should respect your daughter's wishes unless your objective is to permanently rupture your relationship with her.