CHICAGO (CBS) — A former St. Charles North High School employee been sentenced to four years in prison for having sexual contact with an underage student.

Christopher A. Lee, 31, pleaded guilty Monday to one felony count of aggravated criminal sexual abuse, according to the Kane County state’s attorney’s office.

READ MORE: Police Respond To Shots Fired Call At Clark And Lake CTA Stop

Lee, who worked as a dean’s assistant at the west suburban high school, knew the victim because she was a student, prosecutors said.

Sometime between February and May 2015, Lee had sexual contact with the girl, who was younger than 18, prosecutors said. The contact did not take place on school property.

READ MORE: Man Found Shot Dead Under Viaduct In Stony Island Park

Lee, of the 300 block of North 15th Street in St. Charles, was sentenced to four years in prison, according to the state’s attorney’s office. He will receive credit or 42 days served in the Kane County Jail.

He remains free on a $15,000 bond until he begins serving his sentence on Dec. 27, according to the state’s attorney’s office. He must also register for life as a sexual offender.

MORE NEWS: Four In Custody Following Domestic Incident 'Involving A Firearm' At Sky Zone In Orland Park

(Source: Sun-Times Media Wire © Chicago Sun-Times 2016. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)