West was last seen as she was leaving St. Joseph State Hospital in St. Joseph, Missouri, on September 11, 1979. She worked as a nurse's aide there. She never made it to the bus stop and has never been heard from again.

Marvin Lee Irvin allegedly threatened West prior to her disappearance. In 1991, Irvin, a former police officer, confessed to West's murder. She had been a friend of his first wife. Irvin had been investigated as a suspect shortly after West's disappearance and her family believed he was involved, but he passed a polygraph and there was little evidence to implicate him. Police later admitted they made mistakes in the investigation, such as failing to search Irvin's vehicle. He stated he had stabbed her four times in the chest as she sat in his car, then buried her body in a cornfield in Highland, Kansas. Irvin also confessed to killing two other women in 1990 and burying them in the same field. A search turned up the bodies of his other victims, but there was no sign of West.

Irvin pleaded guilty to the other two homicides and is serving a sentence of life in prison. He has never been charged in West's case; it remains unsolved.