BISMARCK, N.D. — A former Standing Rock Sioux official sentenced to 30 years in prison on child sexual abuse charges is appealing his conviction.

The Bismarck Tribune reports that the attorney for 55-year-old Robert Fool Bear Sr. says there was insufficient evidence and an error in jury instructions, among other complaints filed with the 8th U.S. Circuit Court of Appeals.

Authorities say the former Cannon Ball district chairman repeatedly raped a girl over a four-year span. He was convicted in April on four charges.

Fool Bear is housed at a medium-security federal correction institution in Pekin, Illinois. He is eligible for supervised release after 25 years.

Information from: Bismarck Tribune,