The investigation began after the girl gave birth to a daughter in November at University Hospital in Cincinnati. The hospital reported the birth to the Hamilton County Department of Job and Family Services because of the mother's age.
On Wednesday, investigators learned that Michael Chaffer's DNA showed him to be the father, the Cincinnati Enquirer reported. Chaffer is in a jail in Columbus serving a one-year sentence.
Also Wednesday, there was a status hearing on the girl and baby. They originally lived with the girl's mother, who was ordered not to allow any adult men into her home, until investigators found Chaffer there.
The baby is in a foster home, while the girl is living with relatives. The mother has been barred from seeing her granddaughter and can only have supervised visits with her daughter.