Federal district judge Thomas P. Griesa was assigned to hear the case. The crucial expression "pari passu" had not previously been interpreted in any published decision by the courts of the state of New York, but there is no way in U.S. federal civil procedure for a federal district court to "directly" transfer a case to state court if it had not originally started there. (By way of contrast, if NML Capital had sued Argentina in a New York state court, Argentina would have had the option to "remove" the case to federal court.) Instead, the district court was required by "Erie Railroad Co. v. Tompkins" (1938) to make an "Erie guess" as to how a New York state trial court would interpret that clause by applying general principles of contract law in the state of New York as articulated in the published decisions of the New York Court of Appeals and the New York Supreme Court, Appellate Division. The district court ruled in NML Capital's favor and issued broad permanent injunctions against Argentina and the bond trustee. The U.S. Court of Appeals for the Second Circuit (the federal appellate court with jurisdiction over New York) in turn affirmed the district court's interpretation, but did not exercise its optional right to certify that specific issue to the New York Court of Appeals for a ruling on New York state law.