Dettmer attended Bemidji State University and graduated with a Bachelor of Science degree in Health and Physical Education in 1973. He also holds of Masters Of Education degree from St. Thomas University. He subsequently became a teacher in Forest Lake at Forest Lake High School, where he taught physical education and coached wrestling until 2007.
Dettmer was elected in 2006 to the open seat vacated by Representative Ray Vandeveer, who ran for higher office that year. He was re-elected in 2008, 2010, 2012, 2014, 2016, and 2018. He focuses on the issues of education, health care reform, economic growth, transportation, veterans and military affairs, and public safety.[3]
Local elections
2018
2018 Minnesota Legislature - House District 39A[4]