I want to know if it is possible to get child support from some one that has been hiding for 19 years

Generally if there has not been an order put in place before the child is legally an adult, you cannot go back and have the court order back child support. If there was an order which directed him to pay child support then that has been running since it was put in place and there are arrears due to you. If that is the case then you can go to court on a violation petition and have the arrears set and possibly turned into a judgment, which will earn interest, and which the Support Collection Unit should be able to assist you in collecting.

I am not sure what happened when you tried to locate him in the past.. You should consult with an attorney who regularly practices in support court in your state and see if there is some way to reopen your old case based upon his willful avoidance of court. Sometimes courts have a process where old cases can be reinstated because the other party has acted in a manner that prevented the other party from being able to enforce rights against the party who is avoiding them. I don't know that that is possible for you especially since your child is now legally an adult but you really should seek the advice of someone who is really familiar with the court that you want to make an application to. Good luck