A former Iowa elementary school principal will spend at least 15 years in prison after admitting he secretly videotaped students in a boys bathroom. Robert Burke pleaded guilty to one count of producing child pornography. Under the plea agreement, six other child pornography charges were dropped.

A sentencing date has not been set, but the charge of producing child pornography carries a minimum of 15 years and a maximum of 30 years in prison. The 43-year-old Burke was fired as principal of Dubuque’s Sageville Elementary School in June shortly after his arrest. Investigators said they traced images of child pornography to Burke’s home computer.

He admitted hiding a video camera in the boys bathroom at the school and taping students between January and June of this year. Burke served as principal at Sageville Elementary since 2004.