OMAHA, Neb. (AP) — A former Omaha area high school administrator accused of having sex with a 15-year-old student has been sentenced to prison.

A Douglas County Judge Thursday sentenced Matthew Fedde, a former Millard South High School assistant principal, to 18 to 24 years on two counts of first-degree attempted sex assault on a child. Fedde pleaded no contest to the charges in September.

The sentences will be served at the same time, and Fedde will be eligible for parole after nine years.

Investigators say the 46-year-old administrator had multiple sexual encounters with the female student. He was arrested after the girl’s parents found references to the sexual relationship in her diary.

Fedde didn’t speak during his sentencing.