A onetime coach and health teacher at Willmar High School has been charged with sexual misconduct involving one of his students, who also was on his hockey team, that started when she was a ninth-grader and continued until well after she became an adult.

Many of the encounters between Chad J. Akerson, 34, now of Ashby, Minn., and the student occurred while classes were in session. They continued after Akerson left the district in 2012 and joined the high school teaching and coaching staff in Ashby, according to charges filed last week in Kandiyohi County District Court.

Akerson, who had coached junior varsity baseball, girls' soccer and girls' hockey teams at his alma mater of Willmar, remains jailed in lieu of $50,000 bail ahead of a Dec. 15 court appearance on charges of first-, second- and third-degree criminal sexual conduct.

As well as being one of Akerson's students, the girl knew him "as a family friend and looked to him as a sort of father figure while her parents were going through a divorce," the criminal complaint read.

Until last week, when the charges were filed, Akerson was teaching at Ashby High School and coached baseball, said Al Jensen, that district's superintendent. Jensen said Akerson is now on unpaid leave.

The relationship came to light because of a "rumor around town," said Assistant County Attorney Aaron Welch. "Then someone was at a wedding and heard it."

That "someone" was a legally mandated reporter who went to police, said Welch, who added that he knows of no other allegations in Ashby or anywhere else against Akerson.

According to the complaint, compiled after a lengthy police investigation:

The girl told police that Akerson first became her teacher in September 2009, and then her head hockey coach a month later.

Akerson's first move on the 15-year-old came when the girl was at his house watching a movie and he touched her breast over her clothing.

Also, while playing hockey together down the street from his home at Lincoln Park, Akerson would touch her "on the buttocks in a sexual manner," the complaint read.

Soon after a Christmas tournament in Austin in 2009, Akerson asked her for sexually provocative photos. She texted him two pictures, one of them with her breasts exposed.

Sexual intercourse between the two started the next month and occurred three to four times a week until she reached adulthood. Over those years, Akerson was the girl's teacher in three classes and "would have sex before, during and after school in various locations" in his home and car, the girl's home, Akerson's classroom and other rooms at the high school, the complaint continued.

Akerson resigned from the district in October 2012, and the relationship between the two continued until October 2014, when she was 20. Police questioned the woman three weeks later.

After graduating from Willmar High School, Akerson attended Concordia College in Moorhead and played baseball there. He joined the Willmar School District in 2003.