(CNN) — All her life, Carmen Figueroa believed that she was born in the United States. It was what her mother had always told her.
But a State Department investigation found that in fact she was born abroad and brought into the country illegally at a young age. The discovery brought an abrupt end to a 10-year career as an Arizona state police detective.
Figueroa was forced to resign or be fired. Under Arizona law, an undocumented immigrant cannot be a peace officer.
Her record as an officer included praise and promotions.
The case is a reminder of how the country’s immigration laws can turn lives upside down. It raises questions about how potential public employees are screened, and how easily facts about something as basic as a birthplace can be obscured.
“She was great, well-liked. The whole thing is a sad story,” said Bart Graves, a spokesman for the Arizona Department of Public Safety.
Figueroa had joined the force as a highway patrol officer 10 years ago and in 2010 became a detective.
The detective likely would have continued to serve if not for the State Department investigation.
Figueroa’s brother had applied for a passport while he was in the Air Force, Graves said, and during that process the State Department flagged him about his citizenship.
“When she was informed by the State Department that she and her brother were not U.S. citizens, that was the first she’d heard of it,” Graves said. “Her mother had told her she was born in this country.”
The Department of Public Safety was made aware of the investigation in September, and placed Figueroa on paid administrative leave until Monday, when she resigned, Graves said.
The State Department conducted a criminal investigation and in October decided that it will not file any charges against Figueroa, Graves said.
The state of Arizona continues to work with federal officials to determine if any state criminal charges will be filed, Graves said.
Calls to Figueroa for comment were not answered.