An assistant football coach and weight room supervisor for the Columbia Heights school district who pleaded guilty to having sexual contact with a 14-year-old student and sending her more than 600 text messages will start a three-month jail sentence next month.

Christopher Warnke, 29, of Ramsey, was a contract employee hired in August 2008. The school district said he was hired as an eighth-grade football coach, but court documents list him as an assistant football coach and weight room supervisor with Columbia Heights High School.

In fall 2009, several students, including the 14-year-old, obtained his cell phone number and sent him several sexually explicit text messages, implying they were from the mother of a student on the football team, according to the court documents. The 14-year-old eventually told Warnke it was a joke, but he became upset because he was concerned his wife would find out and divorce him, the court document said.

Warnke continued to text the girl even though she told him she was 14, according to the document. On one occasion, Warnke grabbed the girl's hand in the high school weight room and made her touch him sexually, the document said. A search of Warnke's cell phone showed he sent the girl 605 text messages in a two-month period, according to the document. He was terminated shortly after school officials learned of the allegations.

Earlier this month, Warnke pleaded guilty to one count of felony fourth-degree criminal sexual conduct with a child and two counts of felony solicitation of a child to engage in sexual contact. His three-month sentence allows for half of the time to be served on house arrest.

Warnke also must register as a sex offender and go through treatment. He has a three-year stayed sentence for 10 years.

DAVID CHANEN