Guilty plea entered in grisly murder on Blackfoot Indian Reservation

A Browning man, 30, admitted to killing and partially dismembering a member of the Blackfoot Indian Reservation tribe in March 2020, days before taking a woman hostage for several hours and telling a dispatcher that he “liked to kill”.

Jason Avery Mattson, who is also a member of the Blackfoot tribe, entered two guilty pleas in US District Court in Great Falls on March 30 and faces a significant prison sentence despite reaching a plea agreement with prosecutors. Mattson pleaded guilty to one count of second degree murder and one count of kidnapping. He is expected to be sentenced by Judge Brian M. Morris on June 24.

According to court documents, the body of a man identified as John Doe was discovered in a “moderately remote” area of ​​the reservation on March 3, 2020. The Beacon confirmed the identity of the victim with law enforcement. federal but does not identify it. According to a Glacier County coroner, Doe was decapitated and had both hands severed at the wrists.

During the law enforcement investigation into the murder, a witness came forward to say Doe asked to be driven in late February and asked to be taken to several different locations, eventually being dropped off at the Mattson’s caravan. Doe had shown the witness a large bag of methamphetamine before getting out of the car and seemed “frightened”, according to the witness. Doe walked into Mattson’s trailer without knocking.

A week after Doe’s body was found, on March 10, Mattson called Blackfeet Law Enforcement Services and told a dispatcher he wanted to confess to Doe’s murder, providing the victim’s full name, identifying himself as Jason Mattson and telling the dispatcher he was armed with a knife and a gun.

When law enforcement arrived at Mattson’s scene to arrest him, Mattson called dispatchers back and said he had been taken hostage, identified in court documents as Jane Doe. Mattson claimed to be holding her at knifepoint and said he took a hostage “because he killed John Doe”. When a dispatcher asked Mattson about his state of mind, “he said he was going to kill Jane Doe” and at one point added that “he liked to kill”. Mattson held the woman hostage for four hours before she escaped and Mattson was taken into custody.

At the time of the murder, Mattson was on federal probation following a 2017 conviction for assault with a dangerous weapon. In that case, Mattson and his older brother, Jerry Mattson III, were originally charged with three counts, including assault with intent to murder. According to an evidence offering filed with a plea deal in the case, Jason Mattson shot a man in the neck in June 2013 as the victim and his brother were fighting, then shot the man as he walked. was hiding in trees a short time later. Mattson was sentenced to four years in prison in this case and released on October 18, 2019.

The FBI, Bureau of Indian Affairs and Blackfeet Law Enforcement Services have all investigated John Doe’s murder.

Nohemi M. Moore