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Judge Profile:

Judge Mary J. Theisen

Dakota County

Dakota County Courthouse
Phone: (651) 438-8100

Appointed 2000.  Elected in 2002, 2008, and 2014. Current term expires Jan. 2021.


William Mitchell College of Law, St. Paul, Minnesota

  • J.D., 1984
  • Member, Law Review. Author, Note, "A Recommendation for Juvenile Jury Trials in Minnesota", 10 Wm. Mitchell L. Rev. 587 (1984).

University of Minnesota, Minneapolis, Minnesota

  • B.S., Elementary Education, Minor Concentration: English, 1980

North Hennepin Community College, Brooklyn Park, Minnesota

  • A.A., 1978, Honors

Employment Background:

District Court Judge
First Judicial District, State of Minnesota

  • Serve as District Court judge in the seven counties of the First Judicial District: Carver, Dakota, Goodhue, Le Sueur, McLeod, Scott, and Sibley.
  • Chambered in Dakota County since 2008.  Prior, chambered in Scott County.
  • Elected member to the Board of Directors of the Minnesota District Judge’s Association 2003-2009.
  • Supreme Court appointee to the Alternative Dispute Resolution Ethics Board 2006-2008.

Assistant County Attorney
Dakota County Attorney’s Office, Hastings, Minnesota

  • Community Prosecutor, 1999-2000
  • Adult Felony Prosecutor, 1997-1999

Assistant Attorney General
Minnesota Attorney General’s Office, St. Paul, Minnesota

  • Weed and Seed Coordinator, 1996-1997
  • Criminal Division Lead Trial Attorney/Manager, 1993-1996
  • Criminal Division Staff Attorney, 1987-1993
  • Attorney for Minnesota Board of Peace Officers Standards and Training ("POST" Board), 1987-1994
  • Corrections Division Staff Attorney, 1985-1987                   
  • Human Rights Division Staff Attorney, 1984-1985
  • Law Clerk, 1983-1984

Bar Admissions:

Minnesota Supreme Court (1984), Federal District Court of Minnesota (1984). 

Teaching Experience:

Judge Theisen enjoys teaching and has over 25 years teaching experience.  Her teaching activities include:

  • Advanced Trial Advocacy, William Mitchell College of Law, St. Paul, Minnesota.
  • Legal Practicum, William Mitchell College of Law, St. Paul, Minnesota. 
  • Interviewing & Investigating Techniques for Paralegals, Inver Hills Community College, Inver Grove Heights, Minnesota.
  • Exceptional Advocate Training Program; Robins, Kaplan, Miller & Ciresi.
  • Criminal Constitutional Law, William Mitchell College of Law, St. Paul, Minnesota.
  • Criminal Law, Inver Hills Community College, Inver Grove Heights, Minnesota.
  • Criminal Law Small Group Instructor, William Mitchell College of Law, St. Paul, Minnesota.
  • Trial Advocacy/Lawyering Instructor, William Mitchell College of Law, St. Paul, Minnesota.
  • Legal Writing Instructor, William Mitchell College of Law, St. Paul, Minnesota.

Community Organizations:

Judge Theisen has a strong commitment to serving the community. She is a member of an Eagan church. She has contributed to her community and to the legal community through many volunteer services, including work for her church, Habitat for Humanity, painting for Wingspan, working on Dakota County's CATCH House (rehab of homes for displaced individuals), and Loaves & Fishes (food service for those in need). She volunteers many hours to a bicycling group, organizing and leading rides, trips, and other events of interest to the group. She also contributes time to an outdoor organization by organizing and leading special outdoor events. She has participated in "Teens in Government" day, presented to students of all ages at "Student Success" and "Career" days, and formally and informally served as a mentor for first-year law students. She has also volunteered her time as an instructor for the National Institute for Trial Advocacy, and for training for legal aid lawyers.


Throughout her legal career, Judge Theisen has provided training and education to many groups on varied topics. She has trained others on legal updates, professional responsibility, criminal vehicular homicide, sentencing, jury selection, DNA, infant death, search and seizure, and psychotherapist-patient sexual abuse. She also enjoys speaking to students and other community groups about the role of a District Court judge.

Professional Affiliations:

  • Minnesota District Judges Association
  • Minnesota State Bar Association
  • Dakota County Bar Association
  • First District (Dakota and Goodhue counties) Bar Association
  • Past member, Eighth District (Carver, Le Sueur, McLeod, Scott, and Sibley counties) Bar Association
  • Past member, Minnesota Women Lawyers
  • Past member, Inns of Court
  • Past member, National District Attorneys Association