A prison guard at Louisiana State Penitentiary at Angola has been criminally charged after investigators say they discovered she had an “inappropriate relationship” with an inmate.

The Louisiana Department of Corrections says 30-year-old Courtneé Anderson of Natchez, Mississippi, was booked Friday on one count of malfeasance in office by West Feliciana Parish sheriff’s deputies.

Officials say the relationship was uncovered using evidence found on a contraband cellphone seized recently from an inmate.

Anderson resigned during the course of the investigation and the department says she has admitted to the misconduct.

Anderson had worked at Angola since the end of January. She was a sergeant.