OWATONNA, Minn. — An 84-year-old southern Minnesota man has been charged with murder in a 50-year-old cold case in Wisconsin that was once thought to be the work of a notorious serial killer and former Green Bay Packer.

On February 15, 1974, Mary K. Schlais was found dead at an intersection in Spring Brook Township, Dunn County, according to the sheriff’s office there. The police said it was a homicide.

Schlais was from Minneapolis and police believe he was hitchhiking to Chicago to attend an art exhibition.

Decades passed as investigators followed leads, conducted interviews and examined evidence. The Dunn County Sheriff’s Office said it used genetic evidence to find and arrest Jon Miller of Owatonna.

Authorities charged Miller with first-degree murder on Thursday, according to court records. He is in custody, awaiting extradition to Wisconsin.

How authorities identified Miller as a suspect

Charges filed Thursday say investigators found a stocking cap near Schlais’ body in 1974 and collected hairs from it.

Years later, investigators used those hairs to develop a DNA profile of the suspect. Dunn County joined forces with Ramapo College in New Jersey, which specializes in genetic geneology. After interviewing and collecting DNA from multiple potential relatives, authorities were led to Miller, the criminal complaint states.

Before speaking to Miller, authorities went to his daughter and received her genetic profile. The investigation indicated that the hair on the hat belonged to his biological father. Investigators say the fact that Miller was initially adopted made it more difficult to locate him.

On Thursday, investigators met with Miller, who initially denied any knowledge of Schlais’ murder. When told about the DNA evidence, Miller admitted to picking up Schlais while hitchhiking and soliciting “sexual contact,” the complaint states.

He allegedly told investigators that when she said no, he grabbed a knife he had kept in the car and fatally stabbed her in the back.

Schlais had multiple stab wounds when she was found dead, according to the complaint, including defensive wounds to her hands.

According to the complaint, Miller said he drove off the road and tried to hide Schlais’ body in a snowbank, but became scared when a car drove by and left the area.

Miller also admitted that the hat found at the scene was his, according to the complaint. He was arrested following the interview with investigators and is being held at the Steele County Jail.

“Last night we were sitting at the kitchen table and we got a call,” said Mary Dodge, who lives with her husband Jack near the wooded spot where investigators discovered Schlais’ body. His neighbor Denny Anderson was driving alongside Miller when he allegedly left Schlais’ body in the snow and alerted authorities.

“Denny said when he walked by, the guy was just looking at him. He said he’ll never forget the look on his face,” Mary Dodge said.

Previous suspect charged with serial killer, former Green Bay Packer

In 2009, Schlais’ body was exhumed and DNA testing allowed investigators to identify a suspect two years later: Randall Woodfield, a one-time Green Bay Packers draft pick who would later be known as the murderer. I-5.

Authorities linked Woodfield to dozens of murders along Interstate 5 from Washington to California in the 1980s. He is in prison in connection with one murder, but has never confessed to any of the killings.

Woodfield was traveling from Portland to Green Bay at the time of Schlais’ murder, authorities determined, and matched a witness’ description of the suspect. Woodfield was never further linked to or charged with Schlais’ murder.

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