A 36-year-old Stillwater man has been charged with felony sex charges stemming from 2012, when he served as a teacher at a high school in Grantsburg, Wis.
Washington County Attorney Pete Orputt announced Thursday that Robert Koenen was charged by warrant with two counts of third-degree criminal sexual conduct after he was accused developing sexual relationships involving several female students between the ages of 16 and 18.
If convicted on both charges, Koenen faces maximum penalties of 30 years in prison, fines of $60,000 or both.
According to charging documents, Koenen developed relationships with female students in person, online and by text, and at least two of those relationships culminated in sexual intercourse in Stillwater, Minn.
Koenen formerly served as the history teacher at Grantsburg High School along with his wife, who is also a history teacher there. The two coached a group that participated in a National History Day competition.
One of Koenen's alleged victims had been a member of that group for several years and had known him since 7th grade. The criminal complaint claims the girl thought of Koenen as a mentor and a confidant in whom she had confided many personal thoughts and feelings.
Investigators say Koenen used 3 e-mail addresses with the teen, and he also had 2 cell phones that he hid from his wife. Forensic examination of the e-mails and messages showed multiple conversations that were romantic in nature.
In August, the teen drove to Koenen's house and was invited inside. Charging documents claim Koenen had just put his child down for a nap and then took the 16-year-old into his bedroom and initiated sexual contact for the first time; however, the two reportedly had sexual intercourse as many as 5 times before the girl ended the relationship because she realized was wrong, prosecutors allege.
While Stillwater police were investigating the 16-year-old's allegations against Koenen, several other underage girls reported that they had also been to Koenen's house while his wife was away.
A sophomore at the school told Stillwater police she had gone to Koenen to discuss her slipping grades and also confided her personal issues and concerns. When she did, Koenen gave her his personal cell phone number and told her to call him any time to talk, charging documents say.
The student told police she communicated regularly with Koenen for weeks, and the conversations became flirtatious and sexual. She also told police that she drove to Koenen's home and he initiated sex. The criminal complaint states he also had sexual intercourse multiple times with the second 16-year-old student as well.
Koenen was charged by a warrant that can be executed in bordering states.