DUNN COUNTY, Wis. (WFRV) - After Mary K. Schlais was found dead in western Wisconsin back in 1974, her homicide investigation went cold for over 50 years until investigative genetic genealogy led to an arrest on November 7, 2024. According to a release from the Dunn County Sheriff's Office, a viable suspect was recently identified and arrested in connection to the 1974 homicide investigation of Mary K. Schlais. Schlais, 25, was found dead near the intersection of 408th Avenue and 990th Street in the Dunn County town of Spring Brook on February 15, 1974. Her death was ruled a homicide. Potential school shooting averted at Wisconsin elementary school, teen suspect researched, ‘practiced’ beforehand Authorities say their initial investigation revealed that Schlais, who was from Minneapolis, Minnesota, was believed to be hitch-hiking from Minneapolis to an art show in Chicago, Illinois. It was also noted that an eyewitness saw a suspect and suspect vehicle that was believed to be connected to the homicide. Over the past five decades, numerous tips, leads, and interviews were conducted by multiple law enforcement agencies in hopes of finding a suspect. Several items of evidence were also examined and re-examined over the years as technological advances in DNA progressed. In recent years, Dunn County Sheriff's Office Investigators began working with Ramapo College in Mahwah, New Jersey, and their team of Genetic Genealogists. The collaboration paid off, and through investigative genetic genealogy, a suspect was identified. Nearly 2 pounds of fentanyl, valued at over $80,000 seized during Wisconsin search warrant, 2 arrested On November 7, 2024, Dunn County Sheriff's Office Investigators arrested 84-year-old Jon K. Miller of Owatonna, Minnesota, in connection to the homicide of Mary Schlais. Deputies stated that Miller is in custody and awaiting extradition back to Wisconsin. No additional information was provided.