A former Willmar High School teacher has been sentenced to three years in prison for having a sexual relationship with a student. 35-year-old Chad Akerson became sexually involved with the 15-year-old back in 2009. Court records say he continued to have relations with her over the course of a few years. The victim, now 21, came forward last year. Following his release, Akerson will be on probation for 10 years and will have to register as a predatory offender. He was also ordered to pay restitution to his victim.