The next phase centers on Margaret Kempainen, whose trial was delayed by an appeal.
HOUGHTON, Mich. — Jacob Kempainen was sentenced Monday to 15 to 50 years in prison under a plea deal that also makes him a potential witness against his mother in a family murder case.
The sentence resolved the criminal case against Jacob Kempainen but did not close the prosecution tied to Alvin Kempainen’s death. Margaret Kempainen remains charged, jailed without bond and in a delayed court track after appealing rulings that allowed statements to police and blocked discovery of counseling records.
The plea agreement is now the main link between the finished case and the one still pending. Jacob Kempainen originally faced open murder, conspiracy to commit open murder and felony firearm charges in the Dec. 18, 2023, killing of his grandfather. He pleaded guilty in December 2025 to second-degree murder. In exchange, prosecutors dismissed the other counts, and the agreement set a 15-year cap on the minimum prison sentence. The deal also requires him to cooperate with investigators and testify truthfully if called in Margaret Kempainen’s case. Houghton County Prosecutor Dan Helmer said the offer followed lengthy discussions with investigators, a careful review of the evidence and consultation with Alvin Kempainen’s family.
The legal strategy shifted after a court ruling weakened the state’s case against Jacob Kempainen. His statement to Iowa police was suppressed because officers did not honor his Miranda request before questioning. That meant prosecutors could not use the full statement at trial. The suppression ruling did not end the case, but it changed the risk for both sides. Prosecutors still had the death scene, travel evidence, family communications and other investigative material. The defense had a major evidentiary ruling in its favor. The plea gave the state a murder conviction and possible testimony against Margaret Kempainen, while Jacob Kempainen avoided trial on charges that could have brought more severe consequences.
Judge Brittany Bulleit imposed the sentence in Houghton County Circuit Court. Jacob Kempainen received credit for 837 days already served, reflecting the time he spent in the Houghton County Jail after his arrest. Family members gave impact statements before Bulleit announced the punishment, and several asked the court for the maximum sentence. Bulleit said she had reviewed the pre-sentence investigation report, read numerous documents more than once and listened closely to the arguments and family statements. “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. The prison term allows for a maximum of 50 years, with parole questions left for later under Michigan procedures.
The case against Margaret Kempainen is moving more slowly. She was scheduled for trial in January 2026, but that date did not hold after defense attorney Anthony Ruiz filed an appeal in the Michigan Court of Appeals. The appeal challenges Bulleit’s November 2025 decisions denying two motions. One motion sought to suppress statements Margaret Kempainen made during police questioning after her arrest in Iowa. Bulleit ruled that officers had provided sufficient notice of her rights when they read them and later reminded her. The second motion sought discovery tied to counseling sessions involving Margaret Kempainen’s daughter, who was a minor when Alvin Kempainen was killed and was traveling with Margaret and Jacob when they were stopped in Iowa. Bulleit denied that request as well.
The unresolved motions matter because they shape what jurors may hear if Margaret Kempainen goes to trial. Statements to police can become central evidence in a murder case, especially when a co-defendant’s account is disputed or limited by suppression. Counseling records involving a minor raise separate privacy and evidentiary issues. Defense lawyers argued the material could help explain what happened from the minor’s perspective. The court rejected the request, as it had rejected a similar request in Jacob Kempainen’s case. The appeal means the trial court must wait for direction before the case can be reset. No new trial date had been scheduled when Jacob Kempainen was sentenced.
The underlying facts date to the night Alvin Kempainen was killed in his Hancock Township home. Deputies went to the Salo Road address the next morning, Dec. 19, 2023, for a well-being check and found him dead from a gunshot wound to the head. Family concern had grown after he stopped responding to calls and texts. He had sent a message around 9 p.m. Dec. 18 saying the family group had arrived at his home. His son later told investigators he worried the group had gone there to get money after a debit card transaction appeared in Bruce Crossing. Investigators soon identified Jacob and Margaret Kempainen as suspects and found them traveling south toward Iowa.
Clear Lake police arrested Margaret and Jacob Kempainen at a gas station after authorities passed along information that they were headed south on Interstate 35. A younger family member was with them and was released because she was a minor. The arrests led to more investigative work in multiple states, including a search of Jacob Kempainen’s Minneapolis apartment. Search warrant materials later described claims by Margaret and Jacob Kempainen that Alvin Kempainen was not really himself or had been affected by spirits. Jacob Kempainen reportedly said the person in the home was “not grandpa.” Margaret Kempainen reportedly said the 87-year-old moved like a much younger person. Investigators treated those claims as statements in a homicide inquiry, not as an explanation that changed the nature of the shooting case.
Alvin Kempainen’s death left the court with both a family tragedy and a procedural puzzle. The victim was the father-in-law of one defendant and the grandfather of the other. The accused family members came from Wisconsin, the killing happened in Michigan and the arrests took place in Iowa. A third family member was present during travel but was not charged as an adult. The case also moved through weather delays, evidentiary rulings and appellate filings before the first sentence was imposed. Each step has affected how quickly the case can reach a final resolution and what evidence may be available in the remaining trial.
Jacob Kempainen leaves the case as both a sentenced defendant and a possible prosecution witness. Margaret Kempainen remains jailed as the appeal decides what evidence prosecutors may use against her.
Author note: Last updated May 5, 2026.