Stillwater man, a former teacher, accused of having sex with students

A 36-year-old Stillwater man is accused of having sex with two 16-year-olds who were in a history class he taught at a high school in Grantsburg, Wis.

Matthew Robert Koenen, a former teacher at Grantsburg High School, faces two counts of third-degree criminal sexual conduct. If convicted, he faces up to 15 years in prison and a $30,000 fine for each count.

The charges allege Koenen developed significant relationships with several female students in person, online and by text, resulting in sexual encounters at his home in Stillwater. The incidents have been under investigation by the Stillwater Police Department since they were brought to the department’s attention on June 24, 2013. Koenen was arrested Nov. 21.

Police reports state that in the spring of 2012, Koenen and his wife were both teachers at Grantsburg High School and coached a group that participated in the National History Day competition. In June 2012 the team made it to nationals, and one of the alleged victims — whom the couple had known since she was in seventh grade — was part of the group.

Upon returning, the complaint says, Koenen began communicating with the alleged victim through conversations, emails and text messages.

According to police reports, the victim described Koenen as a mentor and confidant whom she trusted. Their conversations became romantic in nature, and authorities allege that in August 2012 Koenen invited the victim to his home when his wife was away. The pair went for coffee, police say, and then went to Koenen’s home, where he put his child down for a nap. Then Koenen allegedly initiated sex with the victim. She told police she didn’t want to participate but didn’t know how to stop it.

They went on to have sex three to four times after that day, according to police. Authorities say the pair’s communication ended in November or December of 2012, when the victim realized the relationship was wrong.

According to court documents, while officers were investigating this case, they also discovered that several other juveniles had been to Koenen’s residence when his wife was away.

The complaint says another alleged victim, who is now 17, was in Koenen’s history class her sophomore year in May 2012. After Koenen asked about her slipping grades, the victim confided some personal concerns to him. Koenen allegedly gave her his personal cell phone and told her to call him any time to talk. They communicated regularly and the conversations became flirtatious and sexual in nature, authorities say.

Koenen allegedly invited this second victim to his home in August 2012 and initiated sex with her. She was 16 years old at the time. They had sex multiple times at Koenen’s Stillwater home, the complaint says. The last time the pair had sex was in May 2013, the complaint says, but he abruptly stopped communicating with the victim around the time the police investigation began.

According to police, Koenen ended up with multiple secret cell phones and multiple email accounts so he could carry on these relationships without his wife’s knowledge.

Koenen sent a message to the second victim asking what she had told police about their relationship, according to the complaint. The victim had initially denied the nature of the relationship, but Koenen told school officials he had exchanged personal text messages with her. He was asked to resign from his position.

Investigators say that at least two other female students had been to Koenen’s home while his wife was away.

Koenen’s initial court appearance takes place on Nov. 27 at 1 p.m.

Contact Avery Cropp at [email protected]