British psychiatrist warns of 'selfie addiction' Updated: Tuesday, March 25, 2014 | MARSHALL, Mich. (NEWSCHANNEL 3) - A Marshall teacher learns his fate after pleading no contest to criminal sexual conduct charges.33-year-old Michael Hagedorn is accused of having a sexual relationship with a 17-year-old girl, while teaching at Marshall Academy.Monday, he was sentenced to spend between 24 months to 15 years behind bars.Hagedorn's sentence is higher than agreed upon in the plea deal, but he chose to take the amended plea.A sense of closure Monday for Matt Davis and his step-daughter after her teacher at Marshall Academy Charter School was sentenced for having a sexual relationship with her.It's been a difficult year, it’s been a challenge," said Davis.She tells us over a period of four months she would find any excuse to meet with 33-year-old Michael Hagedorn when he was alone in his classroom.And despite the fact he was married with three young children, she says he promised he would be with her after graduation.Davis tells us he knew his step-daughter had a crush on Hagedorn and confronted him about it at parent teacher conferences."He directly looked at me and said don't worry about it, I deal with this all the time, I'm used to it, and it won't be a problem," said Davis.Later on, word got out about the relationship. Davis says parents came forward and alerted the school's head master.And he says, police pulled 500 pages of text messages, and discovered the two were also sexting.Davis says his step-daughter was ostracized by her peers, that she dropped out of high school for a semester and her depression led to drugs and alcohol.The life lessons were brutal."Just some naiveness that's now gone, and replaced with the reality of the real world that people will and do take advantage of you," said Davis.Davis believes Hagedorn preyed on his step-daughter, but after his sentencing his family can now begin the healing process."We had somebody who cared more about himself and his own needs, then my child's needs, and as a result, it cost him dearly," said Davis.Davis' step-daughter tells us she's doing much better now and is planning on graduating high school this year.