A Michigan man has confessed to playing a role in the murder of his 87-year-old grandfather, a crime allegedly committed with his mother’s assistance, according to authorities.

Jacob Kempainen, 22, entered a guilty plea to second-degree murder this week in Houghton County court, admitting his involvement in the death of Alvin Kempainen, as reported by local news outlets such as NBC affiliate WLUC. Following this plea, charges of open murder, conspiracy, and firearm possession were dropped.

Under the terms of his plea agreement, Jacob Kempainen has agreed to provide truthful testimony against his mother, Margaret Kempainen, who is facing charges as a co-defendant. Notably, she has not been offered any plea agreement.

The case has drawn attention due to its unusual nature, with defendants purportedly urging investigators to look for evidence of “paranormal activity.”

The incident reportedly took place on December 7, 2023, when Jacob and his 50-year-old mother allegedly traveled from their Wisconsin residence to Alvin Kempainen’s home in Michigan.

The woman’s husband — and Jacob Kempainen’s father — told authorities that he saw a debit card transaction in Bruce Crossing, Michigan, and believed his family was traveling to his father’s home to “get money,” according to court documents obtained by Minneapolis-based news site Bring Me the News.

The husband feared that his father was in trouble.

Days later, Alvin Kempainen allegedly texted his son that the family — which he referred to as “the crew” — had just arrived at his home. He then stopped responding to additional messages and calls from his son, as Law&Crime previously reported.

Deputies with the Houghton County Sheriff’s Office responded to the grandfather’s home at about 10:30 a.m. on Tuesday, Dec. 19, 2023, due to a call requesting a wellness check at a home in the 53000 block of Salo Road, just a few miles south of Lake Superior.

Upon arriving, first responders said they found Alvin Kempainen suffering from an apparent gunshot wound to the head.

The victim was pronounced dead on the scene.

Investigators identified Margaret and Jacob Kempainen as potential suspects in the fatal shooting, and they were reportedly located driving south on Interstate 35 toward Iowa. Authorities contacted local police, and officers were able to apprehend the duo when they stopped at a gas station.

The pair are said to have had a disparate and bizarre telling of events.

Jacob Kempainen allegedly told police that when they arrived at Alvin Kempainen’s home, the 87-year-old had already been killed by malevolent spirits and that the individual in the home was “not grandpa.”

“(Jacob) advised that the spirits stated grandpa opened the well up behind the house and the spirits killed him,” a search warrant reportedly stated. Margaret Kempainen, for her part, said that Alvin Kempainen was “not her father-in-law,” authorities said, with the woman claiming that he had been moving around “like a 20-year-old.”

Margaret Kempainen allegedly told police that her son was the one who killed Alvin Kempainen. However, following the son’s plea deal, prosecutors made clear their priority is ensuring a conviction against the mother.

“The Michigan Supreme Court recently found, inexplicably, that automatic life without parole sentences for 20-year-olds are unconstitutional,” Houghton County Prosecuting Attorney Dan Helmer said, per WLUC. “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. Another strong factor in this plea offer was doing whatever I 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.”

Jacob Kempainen will reportedly be sentenced within the next three months. Margaret Kempainen is scheduled to have a jury trial next month.