The first question is what order, entered where, established paternity? Was custody/support/visitation also established? If that State still has Exclusive Modifiction Jurisdiction, that is where a motion to alter the current situation should be filed. Otherwise, it could be elsewhere. The relevant rules are in the article titled "The Basics of Family Law Jurisdiciton" (along with the substantive rules regarding custody, and a lot of other information) posted here. Once you know where you should proceed, you should consult with a family law specialist there to determine what your options are, up to and including seeking custody of the child.
Answered on Dec 09th, 2016 at 4:04 PM