The Texas Juvenile Justice Department arrested 40-year-old Yuliana Mares on two felony charges on April 22.
Mares is facing a first-degree felony charge of violating the civil rights of a person in custody and improper sexual activity.
She was also charged with a second-degree felony of indecency with a child by sexual contact.
Investigators said the incident happened in February 2025 with a 16-year-old boy who was committed at the Evins State Juvenile Correctional Facility.
While working as an officer at the detention center in Edinburg, the 40-year-old allegedly had sexual contact by touching the teenager's genitals.
Anyone can report misconduct allegations to the Incident Reporting Center by emailing a complaint to TJJD.IRC@tjjd.texas.gov or by calling a 24-hour-a-day toll-free hotline at 1-866-477-8354.