DETROIT (Michigan News Source) — A Detroit police sergeant suspended for working with federal immigration agents is taking the fight to federal court, saying the real violation was punishing her for doing her job.

Sgt. Denise Wallet, a 27-year veteran of the Detroit Police Department, filed a federal lawsuit to block her termination after Chief Todd Bettison moved to fire two officers accused of coordinating with U.S. Border Patrol.

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The lawsuit centers on a Feb. 9 traffic stop where Wallet responded to help identify a driver who allegedly presented a fake Michigan license. After a department fingerprint scanner failed, Wallet contacted Border Patrol at her lieutenant’s direction, according to the complaint. Federal agents later took the illegal immigrant into custody.

Wallet’s attorney says the call was made solely to confirm the driver’s identity—not to enforce immigration law—and did not violate department policy.

“She couldn’t ID the man … so she asked her lieutenant what to do, and the lieutenant said to call Border Patrol,” attorney Solomon Radner told The Detroit News.

Wallet argues the suspension violates her rights and federal law allowing communication between local police and immigration authorities. She is asking a judge to stop the department from firing her while the case moves forward.