Their house was left exactly as they’d left it, with unfinished chores and a significant amount of money untouched in their bank accounts. This suggested they didn’t plan to disappear.

Months later, tire tracks matching their car were found leading off a cliff into the Columbia River. A possible part of their car was snagged by a river rig, but it broke free before it could be recovered. Later, Susan and Virginia’s bodies were found downstream; they had drowned, though the exact cause of death was unclear (Virginia had a head wound). Kenneth, Barbara, and Barbie were never found.

Police suspected foul play, possibly involving the family’s oldest son, Donald, who was in the Navy at the time. A bloodstained gun linked to Donald was found near Cascade Locks, but was never properly investigated. Donald had a strained relationship with his family and acted strangely after their disappearance, but he denied any involvement.

Detective Graven believed Donald was suspicious, but without concrete evidence, the case remained unsolved. The investigation was hampered by a near-fatal diving accident during a water search and was eventually closed. The mystery of the missing Martins remains unsolved to this day.