GREAT FALLS , MONTANA — A Browning man today admitted to murdering a man and to holding a woman hostage by knifepoint on the Blackfeet Indian Reservation, Acting U.S. Attorney Leif Johnson said.
Jason Avery Mattson, 30, pleaded guilty to second degree murder and to kidnapping as charged in an indictment. Mattson faces a maximum of life in prison, a $250,000 fine and five years of supervised release.
Chief U.S. District Judge Brian M. Morris presided. Chief Judge Morris set sentencing for June 24. Mattson was detained.
In court documents filed in the case, the government alleged that on March 3, 2020, law enforcement was called to the Blackfeet Indian Reservation after the discovery of a body, which showed signs of homicide. The body was identified as John Doe. An autopsy confirmed the manner of death was homicide, with evidence of blunt force injury.
In addition, the government alleged that on March 10, 2020, Mattson called Blackfeet Law Enforcement Services, confessed to killing John Doe and told dispatch he had a knife and a gun. While officers were responding to the residence, Mattson called again and told dispatch he was holding a hostage, identified as Jane Doe, at knifepoint. Mattson threatened to kill Jane Doe and held her hostage for about four hours before she was able to escape. Mattson was taken into custody.
Assistant U.S. Attorney Kalah Paisley is prosecuting the case, which was investigated by the FBI, Bureau of Indian Affairs and Blackfeet Law Enforcement Services.