My question involves a child custody case from the State of: GA
History: Three children current ages 19, 17, 17. All are disabled and still in school until the age of 21. Parents were not married for children's birth but were married after. DNA tests were completed and paternity was established and birth certificates were signed. Biological father lives in PA, Birth mom lives in GA with children. Custody, visitation & child support order granted in 2008 in PA. In 2016, father tells PA that children are not residing with mother and order is stopped. Mother still had children in her possession but due to interstate, notice was not received until after order was cancelled and appeal time had passed. Mom has since reapplied and provided proof of custody. Dad has not shown up for court as of yet. Dad has not seen, visited, or spoken to children since 2008 even though there was a court order but has fraudulently claimed them on his taxes at least 3 times. All of which were reported to the IRS.
Questions: Can dad be held responsible for back support for time of fraudulent case closing until now with proof that he lied? The kids will be in school until they are 21, will he have to pay until then? Is there any chance of prosecution against dad for any of this? Any suggestions for this case?

