Tatum O'Brien | Fargo Criminal Defense Lawyer

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Main Office

720 Main Ave
Fargo, ND 58103

Office Hours

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Proudly serving the Fargo, ND and the surrounding areas.

O’Keeffe O’Brien Lyson Attorneys

About Tatum

When you think of a quality that describes the attorney you want working for you, does “tenacious” come to mind? That’s what Tatum’s clients say about her.

Tatum was born and raised in Western North Dakota. Her extensive experience, both in and out of the courtroom, coupled with a work ethic that never stops, has earned her a solid reputation as an attorney who represents her clients with tenacity and skill.

Tatum’s areas of concentration include criminal law, personal injury, and general litigation. In the practice area of criminal defense, Tatum represents clients charged with: misdemeanors, felonies, drug and property crimes, DUI/DWI, juvenile matters.

In her personal injury practice area, she handles catastrophic injury and wrongful death cases, trucking crashes, medical malpractice cases, other motor vehicle crashes and premises liability cases.

Tatum earned her undergraduate degree in Sociology with an emphasis on criminal justice from North Dakota State University, Fargo, North Dakota. She graduated with distinction from the University of North Dakota School of Law. While in law school, Tatum served as a law clerk at the Morley Law Firm in Grand Forks, North Dakota. Tatum also spent a summer as an extern with the US Attorney’s Office, District of North Dakota. Before joining the firm, she was a law clerk for all eight judges in the East Central Judicial District, Cass County, North Dakota.

Throughout her many years in practice, Tatum has established a reputation as a highly skilled and experienced attorney, representing clients in both criminal and personal injury cases.

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Admission

Verified Minnesota

2007

Verified North Dakota

2005

Verified 8th Circuit Court of Appeals

Verified Federal Courts in Minnesota

Verified Federal Courts in North Dakota

Verified Federal Courts in South Dakota

Verified South Dakota

Education

University of North Dakota School of Law

Recognitions & Achievements

Associations
  • Minnesota State Bar Association
  • State Bar Association of North Dakota
  • Cass County Bar Association
  • North Dakota Association for Justice, Executive Board, past President
  • Clay County Bar Association
  • UND Law Mentor Program
  • South Dakota Bar Association
  • Criminal Justice Act Panel for Federal Appointments
  • Past President – North Dakota Association for Criminal Defense Lawyers
  • American Association for Justice – Revitalization Governor, Board of Governors Injury Board
  • Minnesota Association for Justice
  • Served as President of the North Dakota Association for Justice . She continues to serve on the Executive Committee of the Board of Governors.
    2015-2016
  • In Tatum was appointed to the Board of Governors of the American Association of Justice
    2012
  • Member of the Injury Board – a national organization of trial attorneys focused on improving their practices through education and local community involvement
Honors / Awards
  • Dalwhinnie Award for Exemplary Trial Work by North Dakota Association for Criminal Defense Lawyers in
    2010
  • Top 100 Trial Lawyers, National Trial Lawyers
  • SuperLawyer (annually – )
    2013 / present
  • Global Directory of Who’s Who – Attorney Section

O’Keeffe O’Brien Lyson Attorneys Highlights

Criminal, Accident & Injury, Divorce & Family Law, Real Estate, Business

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Premium Member Tatum Denise O'Brien has been a Premium Member since June 26, 2026.

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