Please update us on the search for your DH's daughter...
In the meantime, yes your DH does have rights, assuming he has not had his parental rights severed.
Many pro se litigants have successfully argued and filed the tyoes of actions your DH SHOULD have been filing for the last 7 years. ie; contempt motions of visitation.
Since you learned of this thru a police scanner, that tells me you are geographically close to where the daughter lives. Tell us the state and what his court orders state, perhaps we can help you.
Actually, if harm comes to this child, I really dont see how any blame can be laid at your doorstep, afterall, you guys havent seen her since the age of nine? Why not? Is there a court order preventing visitation?