The deaths of Earlene Ackerman, Matthew Black Thunder and Winona Longee led to a guilty plea and prison sentence.
POPLAR, Mont. — Earlene Lucy Jones Ackerman, Matthew Earl Black Thunder and Winona “Nona Sioux” Longee were found dead inside a Poplar home after Michael J. Ackerman admitted he shot three people, federal court records said.
The three deaths became the center of a federal prosecution on the Fort Peck Indian Reservation. Ackerman, 74, later pleaded guilty to second-degree murder and using a firearm during a crime of violence. He was sentenced to 15 years and six months in prison, followed by five years of supervised release. Prosecutors had sought 27 years and six months, while the defense pressed for less.
The victims were not strangers to Ackerman. Earlene Ackerman, 65, was his wife of 35 years. Black Thunder, 41, was his stepson, a man the defense said Ackerman had raised from an early age. Longee, 35, was Black Thunder’s girlfriend. Their names were tied in court filings to a Sept. 11, 2025, shooting that investigators said began after methamphetamine use inside Ackerman’s home. The defense later wrote that there appeared to be no motive beyond a drug-fueled break from reality. “This was a senseless act of violence fueled by methamphetamine and made easier by the use of a firearm,” the defense said in a sentencing memorandum.
Federal filings said Ackerman told deputies he had been using methamphetamine with the others in the residence. He said he believed Jane Doe 1, John Doe and Jane Doe 2 were “setting him up.” According to the government’s account, Ackerman said he was in a bedroom with Jane Doe 1 when she had a pistol in her hand. He picked up his own Smith & Wesson 9 mm pistol and shot her twice in the head. He then heard movement in the next room. He told deputies he walked into that room and shot John Doe and Jane Doe 2 while they were sleeping.
The bodies were not found until after a report reached law enforcement in Billings. In the early morning hours of Sept. 14, 2025, Yellowstone County sheriff’s deputies received a call saying Ackerman had admitted killing three people. Deputies contacted him in Billings and spoke with him after reading his Miranda rights. Ackerman agreed to talk and told them the bodies were at his residence in Poplar. The record does not fully explain the time between the shootings described on Sept. 11 and the call to deputies on Sept. 14. It also does not describe any warning to the victims before the gunfire.
Fort Peck Law and Justice Department officers went to Ackerman’s Poplar home after Yellowstone County contacted them. Officers received no response at the residence. They obtained a telephonic search warrant from Fort Peck Tribal Court and went inside around 5:30 a.m. The officers found the three bodies Ackerman had described. All three had gunshot wounds. Four 9 mm casings were found near the bodies. The scene matched key parts of Ackerman’s statement to deputies, including the number of people killed and the location of the bodies. The FBI later took part in the investigation with tribal and county officers.
Ackerman was first accused in a federal complaint of three counts of second-degree murder. He appeared in Great Falls before U.S. Magistrate Judge Timothy J. Cavan on Sept. 17, 2025. At that hearing stage, prosecutors said each second-degree murder count carried a possible life sentence, a $250,000 fine and five years of supervised release. Ackerman was detained pending further court action. The case moved to a plea in January, when he admitted to one count of second-degree murder and one count of using a firearm during a crime of violence before Chief U.S. District Judge Brian M. Morris.
The sentencing arguments showed the sharp divide between the horror of the crime and the defense view of Ackerman’s history. Prosecutors asked for 27 years and six months, saying the term should reflect three deaths and the facts described in the court record. The defense said Ackerman had “almost zero criminal history” and described him as polite and respectful during the legal process. The defense also said Ackerman “presents as a very warm person,” language that stood in contrast to the violence described in his own statements. Those competing pictures shaped the sentencing fight but did not change Ackerman’s guilty plea.
Morris sentenced Ackerman to 186 months in prison. The sentence was lower than the government requested, but it still means a long term for an elderly defendant. Ackerman was described in court records as a plumber who had expressed interest in running for a tribal government office. The filings did not say that any political activity played a role in the killings. The public record also does not show a long criminal past. The case instead turned on the September shootings, the firearm, the methamphetamine use and Ackerman’s statements to deputies after the call in Billings.
The prosecution was handled by Assistant U.S. Attorney Kalah Paisley. The FBI, Fort Peck Tribes Department of Law and Justice and Yellowstone County Sheriff’s Office conducted the investigation. The Roosevelt County Sheriff’s Office was also listed in early local reporting as part of the response. The federal forum reflected the location of the killings on the Fort Peck Indian Reservation and the role of federal law enforcement in the case. Once Ackerman pleaded guilty, the major remaining question was the length of the prison term, not whether a jury would hear the facts at trial.
For the victims’ names, the record is brief. It gives ages, family ties and the place where the bodies were found. It does not include extended public statements from relatives or friends in the available court summaries. Still, the relationships show the depth of the loss inside one household. A wife, a stepson and a partner were killed in the same home. The defense itself described the case as senseless. Prosecutors framed the shootings as a grave act of violence that warranted a much longer sentence than the one imposed. The final judgment resolved the criminal case, but it did not answer every question about why the killings happened.
Ackerman’s federal sentence is now in place. The next formal step is completion of his prison term, followed by five years of supervision if he is released.
Author note: Last updated June 29, 2026.