HELENA — On Tuesday, District Judge Michael McMahon sentenced the two people who pleaded guilty in connection with the 2019 killing of Shane White north of Canyon Ferry Lake.
Judge McMahon committed 43-year-old Dewayne Johnson to the Montana Department of Public Health & Human Services for 30 years, with 20 of the years suspended. He also sentenced 34-year-old Serena Kilseimer to the Montana Women’s Prison for 30 years, with 20 of the years suspended.
Last month, Johnson pleaded “guilty but mentally ill” to the mitigated deliberate murder of 56-year-old White. Kilseimer pleaded guilty to accountability for mitigated deliberate homicide.
McMahon gave both suspects the sentence prosecutors had recommended as part of their plea agreement, but he added additional conditions, saying they both posed dangers to society. He restricted Kilseimer from applying for or receiving parole during her 10 years in prison, pointing to the violent nature of the crime and saying she appeared to have “minimal” potential for rehabilitation.
The judge had discussions with prosecutors and defense attorneys over whether he could restrict Johnson’s eligibility for parole, since he was committed to DPHHS custody instead of sentenced to prison. He eventually stated that, if DPHHS eventually transfers Johnson to Montana State Prison, he will not be eligible for parole. If not, McMahon said any recommendation for a review of Johnson’s sentence would return to his court – and he made clear he intended for Johnson to serve the full 10 years.
“Believe me, sir, it took all of me for many, many days to reach the conclusion that I was not going to put the family through a trial by rejecting the agreement,” he said. “Mr. White deserves justice; his family deserves justice; society deserves justice.”
McMahon also ordered Johnson and Kilseimer to have no contact with each other without approval from their case managers or corrections supervisor.
Authorities found White’s body in September 2019, in the area of Cave Gulch Road, north of Canyon Ferry Lake. An autopsy showed he had blunt force and sharp force injuries. Court documents say deputies found two knives near his body.
Johnson’s attorneys said he suffered from schizophrenia – aggravated by use of illegal drugs, particularly meth. In a statement filed with the court last month, he said he believed White had been threatening him and Kilseimer over an extended period of time. He said the three of them had been together in White’s truck and that he believed White was ready to attack him with a knife.
According to the document, Johnson said Kilseimer had held White against the side of the vehicle and that he had hit him and tried to grab his knife. He admitted stabbing him but claimed he believed it was self-defense. Johnson also said in the statement that he later hit White with a rock and cut his throat.
During Tuesday’s hearing, Johnson apologized to White’s family, again saying he “truly believed he was going to kill me.” Kilseimer also said she apologized for “anything in this situation that has caused anyone any emotional harm.”
White’s parents and son testified during the hearing, saying he had had a troubled life but he didn’t deserve to die in such a violent way. They said White had seen Johnson and Kilseimer as friends, and urged the court to impose a strong sentence.
According to court documents, White had previously testified for the state of Montana in a dependent neglect case against Kilseimer and Johnson. However, during the sentencing hearing, Kilseimer’s attorney noted that he had not given negative testimony toward Kilseimer, saying that had perhaps created the appearance of a possible motive that was not there.