RAPID CITY, S.D. (AP) — A Pine Ridge man has pleaded guilty in a fatal ax attack.

Emery Arapahoe changed his plea Monday in federal court in an agreement with prosecutors. Arapahoe entered the plea to second-degree murder in the death of 24-year-old Raymond Waters Jr. and to arson for setting a mobile home where Waters was sleeping on fire in 2017.

The Rapid City Journal says he faces up to life in prison on the murder and arson convictions.

Arapahoe, now 18, was initially charged in juvenile court but had his case moved to adult court. A motive for the killing has not been revealed.