Details of Disappearance
Diane left her family's residence in Kennewick, Washington on June 18, 1985 to visit friends in Seattle, Washington. She joined a 21-year-old friend, Molly A. Purdin (sometimes referred to as Molly Purdin-Clary), sometime during the day and both females were last seen in King County, Washington in the late afternoon hours.
A photograph of Purdin is posted with this case summary. Her body was discovered nearly one month later July 1985, off Index-Galena Road near Milepost 8 in King County. She was a victim of homicide; she had been raped and killed by a blow to the head.
There was no trace of Diane and she has never been heard from again. She was presumed to be a runaway until Purdin's remains were discovered.
In the few years around the time of Purdin's murder and Diane's disappearance, about a dozen other women in their teens and twenties went missing from the area, including Virginia Rambus and Darci Warde. Several of the missing women had links to prostitution, although Diane was not one of those. Authorities believe a serial killer operating in the Seattle area was responsible for at least some of the women's disappearances.
Diane is the offspring of a white American soldier, Elsworth Robbins, and a Vietnamese mother, Dung "Nancy" Robbins. When she was twelve years old, Diane told her mother that her father had sexually abused her. Elsworth was convicted of the crime and Nancy separated from him. It was approximately a year later that Diane disappeared.
Nancy died by suicide in 1991. Diane's older half-brother, Steve Robbins, lives in Michigan and is now a motivational speaker and university professor. She also has several maternal relatives living in Vietnam.
Foul play is suspected in Diane's disappearance due to the circumstances involved in her case. Her disappearance and Purdin's murder remain unsolved.