 The Minnesota Supreme Court has upheld a Grand Rapids man's murderous conviction and life sentence for his involvement in the beheading death of a hymning man in June of 2016. The state's High Court issued the unanimous opinion Wednesday 38-year-old Joseph Thoreson was convicted of premeditated first degree murder in the death of 20-year-old David Heyman in Raleigh, Tasca County. When the conviction carried in automatic life sentence without any opportunity at parole, Thoreson appealed the case on the grounds that prosecution was based largely on the unreliable testimony of an accomplice and other witnesses who were under the influence of drugs. He also alleged that the district court aired by not instructing jurors about the credibility of those witnesses, but the Supreme Court rejected those claims. This was the Thoreson's final hope for securing a release from the mandatory life sentence. Thoreson remains at the maximum security Minnesota Correctional Facility in Oak Park Heights.