The Denver Sheriff Department has run afoul of the U.S. Department of Justice because it made U.S. citizenship a job requirement for its deputies during a hiring spree in 2015 and early 2016.

The sheriff’s department will pay a $10,000 fine and will have to sort through old applications to identify people who were eliminated from consideration because they were not U.S. citizens, according to a news release from the justice department.

The department must reconsider those applicants for future jobs, the justice department said.

In an emailed statement, sheriff’s spokesman Simon Crittle said, “The Denver Sheriff Department maintains its commitment to treat all people with dignity and respect, and is proud to have one of the most diverse workplaces in Colorado.

“While we didn’t commit this violation intentionally, we accept responsibility and are taking steps to clarify policy and amend language in hiring documents.”

Under the U.S. Immigration and Naturalization Act, the sheriff’s department should have considered job applications from any work-authorized immigrant. Instead, the department made citizenship a job requirement in its employment postings.

The settlement with the justice department also requires the sheriff’s department to train its human resources staff on anti-discrimination provisions of federal immigration laws and reviews its procedures to make sure they are in line with federal law, the justice department said.

The department began hiring 200 deputies as part of its ongoing reform effort. The department needed a larger staff to ease deputy fatigue and reduce millions it was a spending in overtime. The move also was expected to give sergeants more time to supervise deputies rather than filling gaps in schedules inside the city’s two jails.