4 friends were found dead in an SUV in a Wisconsin cornfield after a night out at a bar. Officials have called the motive a 'mystery.'

• Four friends from Minnesota were found dead under mysterious circumstances on Sunday.
• A farmer found the bodies in an SUV parked in a cornfield in a small Wisconsin town.
• Police said the motive for the quadruple homicide was a "mystery" and that "everybody's a suspect."

Four friends from Minnesota spent a night out together at a bar in St. Paul on Saturday. On Sunday, the group was found dead 70 miles away in Dunn County, Wisconsin, officials said.

Dunn County Sheriff Kevin Bygd told reporters during a press conference on Tuesday that a farmer found the bodies around 2:18 p.m. in a black SUV that had been driven into a cornfield off a rural road and abandoned, about one hour from St. Paul.

Preliminary results from the autopsies showed the victims died of gunshot wounds, Bygd said.

The victims have been identified as Nitosha Lee Flug-Presley, 30, of Stillwater; Matthew Isiah Pettus, 26, of St. Paul; Loyace Foreman III, 35, of St. Paul; and Jasmine Christine Sturm, 30, of St. Paul.

Pettus was Sturm's brother, Foreman was her boyfriend, and Flug-Presley was her "lifelong" friend, according to the Pioneer Press.

Flug-Presley's dad, Damone Presley Sr., told the outlet the group was hanging out together at a bar in St. Paul on Saturday night and that he knew something was wrong on Sunday when he couldn't reach her.

"She was an outgoing person, a very good mother, exceptional daughter," Presley told the outlet of his daughter. "She was very vibrant, she had a good heart, someone who would lift up your spirits."

Multiple agencies are investigating the deaths, including the FBI. Few details have been released about the potential suspect or suspects, but police believe they left the area after abandoning the SUV.

"I wish we could release more details of our investigation but we have to balance the public's desire to know the details with running the risk of harming our investigation and losing evidence for building a good homicide case," Bygd said in a statement.

When asked about a possible motive for the quadruple homicide, Bygd said that was a "mystery."

"We do not know a motive yet," Bygd said, adding that at this point in the investigation there was no indication that drugs or organized crime were involved.

"Everybody's a suspect at this point," he said.

So far, police say they have not found a connection between the victims and the Wisconsin location they were found in. Bygd said police believe the victims were "randomly brought" there.

He called the case "highly unusual" for the rural area.

"Obviously we've had homicides in the last several years. But something of this magnitude, I've been here for, I'm working on my 33rd year working for Dunn County, and this is a first," he said.