Gazette file photo Houghton County Prosecutor Dan Helmer (left), Defense Attorney David Gemignani (center), and Jacob Kempainen appeared in Houghton County Circuit court in March. Kempainen pleaded guilty of second degree murder this week.

HOUGHTON — Jacob Kempainen, 22, entered a guilty plea Thursday afternoon in Houghton County’s 12th Circuit Court to 2nd Degree Murder for his role in the December 18, 2023 death of his grandfather, Alvin, 86, according to Thursday press release from Daniel Helmer, Houghton County prosecutor.

In exchange for his plea, the Open Murder and conspiracy charges against Kempainen, as well as the firearm charge, will be dismissed. There is a sentencing agreement that the minimum sentence not exceed 15 years in the Michigan Department of Corrections.

The plea agreement requires Kempainen to cooperate with investigators and testify truthfully in the trial of his co-defendant and mother, Margaret Kempainen.

“This plea offer was made after lengthy discussions with investigators, a careful evaluation of the evidence, and in consultation with multiple family members of the victim, Alvin Kempainen,” Helmer, is quoted as saying in the release. “Unfortunately, although Jacob invoked his Miranda rights prior to questioning, Iowa police did not honor his request, and his entire statement was suppressed by the Court. The entire case then hinged on the testimony of his then-juvenile sister, which presented concerns for both myself and the lead detective.”

Helmer went on to say that a recent Michigan Supreme Court decision also factored into plea negotiations while the case was pending.

“The Michigan Supreme Court recently found, inexplicably, that automatic life without parole sentences for 20-year-olds are unconstitutional, Helmer said. “Jacob was 20 at the time of the murder, and that decision took away a lot of the leverage my office had in plea negotiations.”

Helmer said an additional, strong, factor in the plea offer involves his doing whatever he can to secure a conviction against Jacob’s mother, Margaret Kempainen, for her role in this horrible crime. No plea offer has been extended to her, Helmer said.

Jacob Kempainen will be sentenced at a later date by 12th Circuit Judge Brittany Bulleit.

Despite the murder occurring exactly two-years ago, both defendants have had their case repeatedly delayed, the release says.

At another hearing Thursday, Margaret Kempainen’s jury trial, scheduled for January 2026, was once again adjourned to allow her attorney to appeal recent evidentiary rulings in the case to the Michigan Court of Appeals.

“These evidentiary motions were not filed until 15 months after the preliminary examination. This delay, yet another in a long history of delays, was at the request of Mrs. Kempainen’s attorney and while I certainly can understand it from a legal perspective, was a decision by the judge, not by agreement,” Helmer said. “It is frustrating to have these evidentiary issues in front of the Court so long after the case was bound over, adding, “the Houghton County Sheriff’s Office and I share the frustration of the family, and I am sure the general public, in how long this case is taking to proceed to trial. I am, and have been, ready, willing, and able to present this case to a jury and seek justice for Alvin Kempainen and his family.”