On June 25, 2012, the Supreme Court held that certain provisions of Arizona's immigration statute (signed into law in 2010) were preempted by federal immigration law. The preempted provisions include those making it a criminal offense for an undocumented worker to solicit, apply for, or perform work in the state; making it a misdemeanor for an individual to fail to comply with federal alien-registration requirements; and authorizing state and local officers to arrest persons who the officer has probable cause to believe has committed a public offense making the person removable from the United States.

But the Court upheld the section requiring police officers to make a determination of the immigration status of any person stopped, detained, or arrested before the state courts had an opportunity to interpret the law and without a showing that its enforcement would conflict with federal immigration law and its objectives.

The Court's decision today will impact pending cases involving U.S. Department of Justice (DOJ) challenges to other state immigration laws (including Alabama and South Carolina) currently in federal court.