MISSION, S.D. — A Mission man has been sentenced to eight months in federal prison for assaulting a federal officer during a disturbance call earlier this year.

According to the U.S. Attorney’s Office, 38-year-old Shannon Dunham became verbally aggressive, grabbed a Rosebud Sioux Tribe Law Enforcement Services officer, and then brandished a knife when the officer responded to a report that Dunham was causing a disturbance at a residence in Mission.

Dunham was convicted of Assaulting, Resisting, and Impeding a Federal Officer. He was indicted by a federal grand jury in November 2024 and pleaded guilty in August 2025.

He will also serve three years of supervised release following his prison term.