A federal judge has scheduled a December trial for a 22-year-old man charged in a triple murder on the Crow Reservation in southeastern Montana.

U.S. District Judge Richard Cebull set Sheldon Bernard Chase's trial for Dec. 27.

Chase, who has pleaded not guilty to three counts of first-degree murder, is accused of shooting his grandmother, cousin and cousin's boyfriend on Oct. 4 at the family's home near Lodge Grass. He was arrested the next day in Spokane, Wash.

An FBI affidavit says a 3-year-old boy who witnessed the shootings saw Chase fighting with his cousin's boyfriend earlier that day.

Authorities have said Chase suffers from an unspecified mental illness and had stopped taking his medications at some point before the shootings.

Associated Press