MISSION, S.D. - A 21-year-old Mission man has been sentenced to 15 years in federal prison for voluntary manslaughter and assault with a dangerous weapon after fatally beating a man last summer.

Prosecutors say Eric Roubideaux II attacked a family member in the early morning hours of July 7, 2024, striking her with a garden hoe and stomping on her with shod feet. She suffered a concussion and a scalp laceration that required medical treatment.

After fleeing the residence, Roubideaux confronted a man walking along the street, striking him with a stick and knocking him to the ground. Roubideaux then kicked and stomped the man with shod feet, including repeatedly kicking the man in the head. The man died from blunt force trauma. Roubideaux fled the scene but was arrested a short time later.

A federal grand jury indicted Roubideaux in August 2024. He pleaded guilty in May of this year.

The U.S. Attorney’s Office prosecuted the case under the Major Crimes Act, which requires certain violent crimes in Indian Country to be handled in federal court. The case was investigated by Rosebud Sioux Tribe Law Enforcement Services and prosecuted by Assistant U.S. Attorney Kirk Albertson.