Supreme Court's Southern Union Ruling Limits Judges WASHINGTON (Reuters) - The United States Supreme Court on Thursday overturned an $18 million penalty against a pipeline operator for illegally storing mercury, ruling that a jury must determine any facts that increase a defendant's maximum potential sentence, even a criminal fine. A jury found the company, Southern Union, guilty of storing mercury without a permit at a building in Rhode Island. A federal trial judge imposed a $6 million fine and $12 million in community service obligations. Southern Union, which is based in Texas, argued that the jury found only that the company had violated the law for at least a day, which carries a maximum fine of $50,000. Federal prosecutors said the company had violated the law for 762 days. A federal appeals court ruled against the company and said the trial judge could determine the number of days of violation in calculating the penalty. By a 6-to-3 vote, the Supreme Court overturned that ruling and sent the case back to the appeals court. Justice Sonia Sotomayor wrote in the majority opinion that the Constitution's Sixth Amendment right to a jury trial required that the jury, rather than the judge, find any facts necessary to increase the fine imposed in a criminal case. She said the Supreme Court used similar reasoning in a ruling in 2000 that a jury must find any facts that increase the length of a prison sentence. Justice Sotomayor said the same principle applied to the imposition of fines. She rejected the federal government's argument that extending the 2000 ruling to criminal fines would prevent states and the federal government from adopting laws that calibrate the amount of the fine to a defendant's culpability. Justices Stephen G. Breyer, Anthony M. Kennedy and Samuel A. Alito Jr. dissented. In late March, Southern Union completed a merger with Energy Transfer Equity. The case is Southern Union Co. v. United States, 11-94.