The Ninth U.S. Circuit Court of Appeals on Monday ruled to uphold an injunction against controversial Arizona state law SB 1070. In July 2010—only a day before the law was to go into effect—the U.S. Department of Justice (DOJ) filed suit in federal court to block six of the legislation’s toughest statutes. Monday’s ruling agreed with the DOJ’s position that immigration policy falls under federal jurisdiction and not that of individual states.

SB1070 in its original form required state law enforcement to check an individual’s immigration status while enforcing non-immigration-related laws, provided there is “reasonable suspicion” that the person may be undocumented. While the DOJ contested six of the law’s provisions, the rest went into effect on July 29, 2010, and included penalties for municipalities with more lenient approaches to undocumented immigration, as well as sanctions on employers who hire undocumented workers.

Arizona Governor Jan Brewer, who  filed a countersuit against the DOJ in February, 2011, will likely take her case to the U.S. Supreme Court. However, because SB 1070 only affects Arizona, there is no guarantee that the Supreme Court will agree to hear the case, in which case the Circuit Court’s ruling would stand.