In Michigan, Jacob Kempainen was sentenced after pleading guilty in the 2023 shooting death of Alvin Kempainen.

HOUGHTON, Mich. — A Wisconsin man was sentenced Monday to 15 to 50 years in Michigan prison for killing his 87-year-old grandfather inside a rural Hancock Township home in December 2023.

Jacob Kempainen’s sentence closed one part of a family murder case that began with a well-being check, crossed state lines and later raised questions about police interviews, family testimony and a pending case against his mother. The 22-year-old pleaded guilty to second-degree murder under an agreement that dismissed more serious charges and requires his cooperation with prosecutors as Margaret Kempainen’s case continues.

The case began the morning of Dec. 19, 2023, when Houghton County sheriff’s deputies went to Alvin Kempainen’s home on Salo Road, several miles south of Lake Superior. Authorities had been asked to check on him after family members could not reach him. Deputies found him dead from an apparent gunshot wound to the head. Investigators quickly focused on Jacob Kempainen and his mother, Margaret Kempainen, who had traveled from Wisconsin to Michigan before the killing. Police later located the two in a vehicle heading south on Interstate 35 and arrested them after a stop at a gas station in Clear Lake, Iowa. Alvin Kempainen’s son had told investigators he feared his father was in trouble after seeing a debit card transaction in Bruce Crossing, Michigan, and after receiving a final text from his father on Dec. 18 saying “the crew” had arrived at the house.

At sentencing, Houghton County Circuit Judge Brittany Bulleit imposed the 15-year minimum term that was tied to the plea agreement. Jacob Kempainen received credit for 837 days already served in the Houghton County Jail. Family members gave victim impact statements before the sentence was announced, and several asked the court for the strongest punishment allowed. Bulleit said she had reviewed the pre-sentence report and case materials more than once and had taken the family’s statements into account. “I would like to thank the family of the victim for their courage to speak about the impact this has had on their lives,” Bulleit said in court. The sentence allows Jacob Kempainen to serve as many as 50 years in prison, though any future release decision will depend on state corrections and parole procedures.

Jacob Kempainen was first charged with open murder, conspiracy to commit open murder and a felony firearm count. He later pleaded guilty to second-degree murder in December 2025. Prosecutor Dan Helmer said the offer came after talks with investigators and members of Alvin Kempainen’s family, along with a review of the evidence. Under the deal, Jacob Kempainen must cooperate with investigators and testify truthfully in proceedings against Margaret Kempainen. The agreement also came after a key setback for prosecutors. A court suppressed Jacob Kempainen’s statement to Iowa police after finding that officers did not honor his Miranda rights. That ruling removed a major piece of evidence from the state’s case against him, leaving prosecutors to weigh the strength of the remaining evidence before trial.

Court filings and search warrant details gave the case an unusual turn. Investigators said Margaret and Jacob Kempainen made claims about spirits and possession after their arrests. Jacob Kempainen reportedly told police that when they arrived at Alvin Kempainen’s home, they believed the man inside was “not grandpa.” Margaret Kempainen reportedly said Alvin Kempainen was not her father-in-law and had been moving around “like a 20-year-old.” Investigators also sought items tied to those claims during a search of Jacob Kempainen’s Minneapolis apartment. Authorities described the statements as part of the investigation, not as a finding that the killing had any supernatural cause. The motive remains disputed in public records, though one family member told police he believed the trip to Michigan may have involved money.

The case also includes a third family member who was not charged as an adult. Jacob Kempainen’s sister, identified in earlier court references by initials because she was a minor at the time, was traveling with Margaret and Jacob when police stopped them in Iowa. She was released after the arrests. Defense attorneys later sought records tied to her counseling, arguing that they could help explain events from her point of view. Judge Bulleit denied a similar defense request in Jacob Kempainen’s case in 2024 and later denied a related request in Margaret Kempainen’s case. Those rulings have become part of the continuing legal fight over what evidence may be used at Margaret Kempainen’s trial.

Margaret Kempainen, who is Alvin Kempainen’s daughter-in-law and Jacob Kempainen’s mother, remains jailed without bond while her case moves through court. She has been charged in connection with Alvin Kempainen’s death and has not been sentenced. Her attorney, Anthony Ruiz, has challenged Judge Bulleit’s rulings that allowed statements Margaret Kempainen made to law enforcement and denied access to counseling records involving the minor. The defense appeal has delayed the trial schedule. A January 2026 trial date did not go forward after the appellate filing, and no new trial date had been set as of the sentencing in Jacob Kempainen’s case.

The sentencing also followed a weather delay. Jacob Kempainen had been scheduled to learn his punishment in March, but the hearing was postponed after blizzard conditions closed the Houghton County Courthouse. The delay added several more weeks to a case that had already stretched more than two years from Alvin Kempainen’s death. In court, the focus returned to the loss at the center of the case. Family members described Alvin Kempainen as a father and grandfather whose death broke trust inside the family. Prosecutors said the plea served both the punishment phase for Jacob Kempainen and the evidence needs of the pending prosecution against his mother.

The sentence moves Jacob Kempainen’s case from Houghton County court to the state prison system. The unresolved question now shifts to whether Margaret Kempainen will face a jury once the appellate fight over evidence is decided.

Author note: Last updated May 5, 2026.