Japel disappeared with her 73-year-old boyfriend, Kenneth William Miller. Both are originally from McMinnville, Oregon, but they went missing from Quartzsite, Arizona. A photograph of Miller is posted below this case summary. The couple lead a nomadic lifestyle and traveled frequently in their 25-foot 1976 Sportscoach motor home and black and silver Dodge Ram pickup truck. They would be out of touch with their families for months at a time as a result. The exact date of their disappearances is unknown. Japel and Miller's motor home was found abandoned in a remote area near Redmond, Oregon in mid-2006. Their truck was found in Montana. The last activity on their bank accounts was in June 2006. Japel and Miller were last known to be in the company of a friend, Gregory Allen "Groundog" Cole. A photograph of Cole is posted below this case summary.

On May 17, 2007, Cole shot a police officer in Quartzsite. The officer was wearing a protective vest and survived the shooting, although he was hit seven times. Cole was already wanted on other, unrelated felony charges and authorities started a manhunt for him. Because Japel and Miller were missing and were last known to have been with him, there was concern for their safety. Cole's body was found in the Arizona desert, twenty miles from the Mexican border, on May 23. He had shot himself to death. The license plates on his motor home had been taken off Japel and Miller's pickup truck.

In June 2007, authorities searched the area where the missing couple's motor home had been found last year. They found Miller's body buried in a shallow grave there. There was no sign of Japel, however, and she has never been heard from again. She and Miller never married, but they had been together for about thirty years prior to her disappearance and his death.

Authorities believe Cole probably murdered both Miller and Japel, and they are searching for Japel's remains. Her case remains unsolved. Both Oregon and Arizona police are investigating.

Left: Kenneth Miller;
Right: Gregory Cole