Ruth was last seen in her home on Leslie Road in Dane County, Wisconsin on November 4, 1983. She has never been heard from again. None of her clothing, cosmetics, medication or personal grooming items disappeared with her, but a relative found her car parked at Dane County Regional Airport. Her loved ones stated it would be very uncharacteristic of her to abandon her three adult children and her elderly parents. Her second husband, Gary W. Homberg, initially claimed some of Ruth's jewelry, including a diamond ring, a diamond bracelet, and a watch, disappeared with her. In fact, they had not, and he had the items sold or reset after her disappearance.

In 1989, Gary was convicted of first-degree murder in Ruth's case. At the time he was charged, he was already in prison for an unrelated crime; he was convicted of embezzling $645,000 from his employer. He had been having an affair with his wife's daughter-in-law, Sharon Jacobson, in 1983. Jacobson told authorities Gary confessed the murder to her. Authorities believe he killed her in their home on the night of her disappearance and possibly disposed her body in an industrial furnace. They believe the motive was that Ruth had found out about Gary's affair and threatened to tell his employer he about his embezzlement.

Gary appealed his conviction, but the appeal was denied. He is still incarcerated and has never revealed his wife's whereabouts.

Ruth's remains have never been found.