Judge Middendorff graduated from Loyola University of Chicago in 1977. He received his J.D. degree from DePaul University in 1980. He served as an Assistant State’s Attorney of Clinton County from 1980-1984 and then as the State’s Attorney of Clinton County from 1984 until September of 1991. From September 6, 1991, to November 30, 2010, he served as an Associate Circuit Judge in the Fourth Judicial Circuit. On December 1, 2010, Judge Middendorff was sworn in as the Resident Circuit Judge of Clinton County.