Sumner focuses his practice on tort law. Immediately prior to joining Dinsmore, he worked for a short period as an attorney for Legal Aid of West Virginia serving as a Mountaineer Rental Assistance Program Attorney. In this capacity, he focused on landlord tenant law, including habitability litigation, evictions, and other related areas of practice relating to housing security. Sumner also has extensive litigation experience in the areas of family law and personal injury matters from inception to resolution. He is a trained and certified mediator, arbitrator, and guardian ad litem.

Sumner has been involved in community outreach through speaking and advocacy engagements with the ReEntry Alliance, Greater Wheeling Coalition for the Homeless, Ohio Valley Homeless Coalition, the Soup Kitchen of Greater Wheeling, and Catholic Charities.