A University of Minnesota student and his mother are charged in the shooting death of his grandfather in Michigan's Upper Peninsula last month.

Jacob Kempainen, 20, and his mother, Margaret Kempainen, 50, are both charged with murder and in custody while undergoing competency evaluations to see if they're fit to stand trial. The mother accuses her son of killing grandfather Alvin Kempainen, 87, who was found Dec. 19 with a gunshot wound to the head, according to the search warrant. Both are scheduled to make their next court appearance in March.

The warrant filed in Hennepin County District Court requests a search of the student's Minneapolis apartment 340 miles away from the crime scene in the rural Michigan township.

"Murders happen [here] once a year on average, maybe twice," Houghton County Sheriff Joshua Saaranen told the Star Tribune in a phone interview Monday. "It's uncommon to have a homicide in the first place. … This one is just a little more unique with family being involved."

Saaranen said there are theories on motives that are outlined in the search warrant. He said the son and mother were "potentially interested in gaining some monetary value out of coming up here" from Wisconsin on Dec. 18. But Saaranen added that "there was nothing taken from the residence after the homicide."

Jacob Kempainen's public defender, David Gemignani, would comment only on the status of the case and ongoing psychological exams. He confirmed that his client was a junior at the University of Minnesota when the case was charged. A university spokesman said Kempainen enrolled for spring 2024 classes in the college of science and engineering.

Saaranen said one of his deputies assisted a special agent with the Bureau of Criminal Apprehension (BCA) when searching Kempainen's apartment earlier this month near campus at 1015 Essex St. SE.

According to the search warrant:

Jacob Kempainen's father, Alan Kempainen, who lives in Hartland, Wis., told police that his kids and wife left him Dec. 7 and he had not seen or spoken to them since. On Dec. 18, he got an email saying his wife's debit card was used at a gas station in Bruce Crossing, Mich., which indicated she was headed to his father's home, likely in search of money.

Alan called his father to warn him of the incoming visitors, and his dad texted him shortly before 9 p.m.

"ALAN The crew has arrived Will see what happens. Will [keep] you informed," the text stated.

Alan texted his father three more times but never heard back. The next day, he shared with investigators more debit card transactions that helped lead to the arrest of his wife and son in Iowa. Transactions show Margaret stopped in Moose Lake, Minn., around 4:15 a.m. Dec. 19, followed by another transaction in Clear Lake, Iowa, at 7 p.m.

Police took Margaret, Jacob and a minor girl into custody. The girl said that Jacob told her to stay in the car when they arrived at her grandfather's house Dec. 18. She said that Margaret Kempainen was carrying a gun when she exited the house.

Jacob admitted to being at the house. He said he went there seeking shelter and believed his grandpa was dead because spirits killed him. Margaret said Alvin's spirit came to her a few weeks prior and told her that he died.

She said that Jacob shot Alvin in the head and she told her son to shoot him again.

A Houghton County detective told the BCA special agent that Jacob claimed his father's family was involved in witchcraft and his grandpa's body was possessed by previous victims. Jacob had told authorities that his father dumped people he killed in a well behind his grandfather's house.

The detective said the stories all sounded similar to the 2015 horror movie "The Visit." And the detective also expressed concern that Jacob was using medications or controlled substances that led him to believe his grandfather was possessed by spirits.

Jacob's father also told authorities that he believed his son had drugs in his Minneapolis apartment.

The BCA agent didn't find any drugs. They were also on the lookout for "paranormal activity, spirits, possession of bodies including but not limited to the 2015 movie, 'The Visit.'" No such evidence was recovered.

The agent did, however, locate a handgun case and receipt for a gun holster in the apartment.

The warrant was approved Dec. 26 and executed the next day; BCA returned to the apartment in early January when the property manager said Jacob received packages that contained gemstones and crystals.

Messages were left with Margaret Kempainen's defense attorney, Antonio Ruiz. The prosecuting attorney declined to comment.