The van driver who authorities said gave them a fake name following a fatal bus crash has been identified as a 24-year-old woman from Guatemala, immigration officials said Monday.

Authorities said the driver is 24-year-old Olga Marina Franco from Guatemala. The woman first gave investigators the fake name Alianiss Nunez Morales, telling them she was 23 and from Mexico.

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Lyon County Attorney Richard Maes on Friday charged the woman with four counts of criminal vehicular homicide, driving without a license and a stop sign violation. She's also charged with running a stop sign and driving without a license.

The federal Immigration and Customs Enforcement (ICE) agency has filed paperwork to keep Franco in custody after the criminal case is resolved, saying it has developed probable cause that she is an illegal immigrant. Franco's fingerprints didn't show up in its database, indicating she had no prior contact with U.S. immigration authorities, the agency said in a written statement.

ICE officials said they planned to assist the Minnesota State Patrol and other law enforcement agencies in investigating the circumstances of the crash.

Also Monday, the two brothers killed in the crash were remembered at their joint funeral service. The funeral for Jesse Javens, 13, and Hunter Javens, 9, was held at Lakeview School in Cottonwood, where classes had been canceled.

More than 1,000 people attended the funeral Sunday for Emilee Olson, 9. The funeral for Reed Stevens, 12, of Marshall, has been scheduled for Thursday at the school.

Franco was driving a van that failed to stop at a stop sign last Tuesday before hitting a bus carrying 28 students from Lakeview School, according to Maes.

The accident happened near the small town of Cottonwood, in southwestern Minnesota.

The bus driver and at least one motorist said Morales did not stop at the stop sign, court documents said. The bus driver, Dennis Devereaux, told police it appeared the van wasn't going to stop, and "he did not have time to hit the brakes or accelerate."

The criminal vehicular homicide charges are felonies, each punishable by up to 10 years in prison and a $20,000 fine. The other charges are misdemeanors.

Two brothers, the daughter of a teacher at Lakeview school and the son of a former Lakeview teacher, were killed in the crash.

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