An 84-year-old man was arrested this week in connection with the slaying of a woman hitchhiker 50 years ago in Wisconsin.

Mary K. Schlais, 25, was found dead on February 15, 1974, at an intersection in Spring Brook, Wisconsin, Dunn County Sheriff’s Office said.

A Minneapolis woman was killed while hitchhiking to a Chicago art show, Sheriff Kevin Bygd said Friday.

“This was a very bright lady who had a very bright future ahead of her,” he said. “His life was taken.”

Although investigators have worked on the case for decades, following up on tips and gathering evidence, “no viable suspects have been identified,” according to the sheriff’s office.

But through forensic genetic genealogy, Bygd said investigators found 84-year-old Jon Miller in his apartment in Owatonna, Minnesota. Miller on Thursday “confirmed his involvement in Mary’s murder” after 50 years, Bygd said.

Miller is awaiting extradition to Wisconsin, Bygd said. It was unclear Friday afternoon whether Miller had retained an attorney.

Bygd said he was ecstatic when he heard of Miller’s arrest.

“It was hard for me to control my excitement,” he said. “You know, I’ve been here with this agency for 35 years and this case has been worked on for all those 35 years.”

The sheriff continued, “This is a huge win for our agency.”

The sheriff’s office said in recent years it worked with Ramapo College in Mahwah, New Jersey, and its team of genetic genealogists helped identify Miller as a suspect.

Through genetic genealogy, law enforcement uses commercial DNA databases to find family matches to the DNA of a suspect, victim, or missing person.

Last month, authorities in Arizona announced that they used genetic genealogy to identify a John Doe whose remains were found near the Hoover Dam more than a decade ago. The man has not been seen by his family for almost 30 years.

Don Schlais, 79, of Minneapolis, said Friday he never thought he would see the day an arrest was made in his sister’s death.

“It’s just surreal. You don’t expect that after all this time,” he said.

Schlais said his sister earned a bachelor of arts degree from the University of Minnesota and applied to graduate school. She was passionate about horses and riding, he said.

Schlais credited law enforcement and the forensics team for the arrest. He said whatever happens to Miller is out of his hands.

“I’m going to let go and let God,” he said. “I guess he’ll take care of it. He will have to pay karma when he dies.”