Federal identity theft charges have been filed against Olga M. Franco, the woman accused of causing the school bus crash that killed four children in Cottonwood, Minn.

Franco, 24, of Minneota, Minn., was charged with two counts of aggravated identity theft and two counts of false representation of a Social Security number in U.S. District Court on Friday.

She was previously charged in state court with four counts of criminal vehicular homicide.

Federal prosecutors allege that Franco gave a false name and Social Security number after her van hit the school bus on Feb. 19.

Franco identified herself as Alianiss Nunez-Morales, but officials later learned that the real Morales was from Puerto Rico and that Franco was in the country illegally.

Franco had prior traffic arrests in 2006 and in January, but each time officers issued tickets and gave her a ride home without checking her immigration status.

Similar false identity charges also were filed against Franco's boyfriend, Francisco Sangabriel-Mendoza, 29, of Minneota. Sangabriel-Mendoza, the van's owner and an illegal immigrant from Mexico, is accused of using the name of Samuel Rivera-Melendez.

Anyone with information on Sangabriel-Mendoza's whereabouts can call the Immigration and Customs Enforcement's toll-free hotline at 1-866-347-2423.

If convicted, Franco and Sangabriel-Mendoza face up to five years in prison on each false representation count and two years on each identity theft count.

Terry Collins • 612-673-1790