The issue has divided federal appeals courts around the country and the justices said Monday they will resolve the issue after hearing arguments next year.
The central question is whether the defendant must know that the counterfeit identification belongs to someone else. Federal prosecutors have increasingly been bringing the more serious identity theft charges against undocumented immigrants, including many who were arrested in raids on meatpacking plants.
Defense lawyers have argued that their clients should not be charged with stealing an identity because the immigrants were seeking documentation only to allow them to work. They didn't know if the numbers were fictitious or belonged to someone else, their lawyers say.
"When a person makes up a Social Security number, having no idea whether it belongs to someone else, it is hard to see how that conduct qualifies as 'theft' - much less 'aggravated theft,"' said the lawyers for Ignacio Carlos Flores-Figueroa, a Mexican national who was convicted of the crime.
The Bush administration, however, contends that the conviction was justified under a provision of federal law that makes it a crime to "knowingly" use a means of identification of another person.
The 8th U.S. Circuit Court of Appeals, based in St. Louis, agreed with the administration and upheld Flores-Figueroa's conviction.
He worked at a steel plant in East Moline, Ill., since 2000.
Originally, he worked there under an assumed name, false Social Security and alien registration numbers. In 2006, he told his employer he wanted to be known by his real name and submitted new identification documents.
This time, though, the Social Security number belonged to someone else, and his green card number was that of yet another person. Suspicious, the employer contacted immigration authorities, who arrested Flores-Figueroa.
The five-count indictment against him included two counts of aggravated identity theft. A judge added two years to Flores-Figueroa's sentence after his conviction.
Federal appeals courts based in Atlanta and Richmond also have ruled in the government's favor in similar cases, while the appeals courts based in Boston, San Francisco and Washington, D.C., have sided with defendants.
The case is Flores-Figueroa v. U.S., 08-108.
