Dagmar Louise Linton, 59, and her husband Robert vanished on August 22, 1986, while on a long retirement road trip. The couple had stayed at Naco West Campground in Brinnon, Washington, and left in their gray and white 1982 Dodge Ram pickup for a day of sightseeing; they never returned or made contact with family as they customarily did.

The pickup was recovered the same day abandoned in the Seattle-Tacoma International Airport parking garage. Investigators found blood and hair in the vehicle consistent with a violent struggle, and the amount of blood led the family to hold a memorial service a few months later. The Lintons’ credit cards were subsequently used across several states; receipts from those transactions showed handwriting that investigators later matched to Charles Thurman Sinclair, and items bought on the cards were found in Sinclair’s storage shed. Sinclair was arrested in Alaska in August 1990 and died in custody in October 1990 before he could be questioned about the Lintons. The couple’s bodies have never been found and their ultimate fate remains unknown.

Anyone who knew the Lintons, saw them in late August 1986, or has information about their travel or the pickup’s movements is asked to come forward.