An Arizona police detective was forced to resign after confronting her mom and discovering that she is actually an undocumented immigrant, born in Mexico and brought into the U.S. when she was young.

Carmen Figueroa apparently was told by her family that she was born in the U.S. though she was actually born in Sinaloa, Mexico, Arizona Department of Public Safety spokesman Bart Graves said Wednesday.

"It was pretty clear as it went up the chain (of command) that she would be terminated."

- Arizona Department of Public Safety spokesman Bart Graves

He said Figueroa's status was discovered when the State Department processed a passport application submitted by her brother, who is serving in the U.S. military.

Figueroa, 42, resigned Monday but would have been fired if she hadn't stepped down, according to Graves, who said a criminal investigation continues.

Arizona law requires sworn police officers to be U.S. citizens, and Graves said the state police agency would have terminated her for fraud and misrepresentation for "not meeting the qualifications."

Figueroa worked in southern Arizona and was with the department for 10 years, most of that time as a Tucson-based Highway Patrol officer. She became a criminal investigations detective in 2010.

"She told us she was always under the impression through her mother that she was born in this country, and she did not really find out until this summer ... that she was an illegal alien through, I believe, a confrontation with her mother," Graves told the Associated Press.

He said Figueroa "had an exemplary record" and the circumstances of her departure don't put any investigations or prosecutions at risk.

Calls to a Tucson-area phone listed under Figueroa's name were not answered Wednesday, and Graves said he did not know whether she has an attorney.

Graves said the DPS was informed of Figueroa's status on Aug. 22 and she was placed on administrative leave with pay Sept. 4.

"It was pretty clear as it went up the chain (of command) that she would be terminated," he said.

According to Graves, Figueroa previously worked for the federal Bureau of Prisons as a secretary and for the Pima County court system as a secretary and an officer.

When Figueroa was hired to the state police force, she submitted a birth certificate from Texas and a driver's license and high school diploma from California, Graves said.

There was nothing suspicious at the time about the documents, but Graves declined to discuss whether authorities now question the legitimacy of any of the papers.

However, he said the DPS was "absolutely having in-depth discussions right now to prevent this from happening again."

Based on reporting by the Associated Press.

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