Forensic tests have helped identify the remains of a man last seen in 1998, officials said. The tests were conducted 26 years after the remains were first discovered in a sleeping bag in the backcountry of Washington state's Olympic National Park.

Joseph Louis Serrao Jr. was originally from Hawaii and had been in Washington prior to going missing, his family told Othram, the forensic laboratory that helped National Park Service investigators solve his case. The family said they had not heard from him since 1998. 

About two years later, in July 2000, a researcher discovered human skeletal remains in a remote part of Olympic National Park, along the Sol Duc River, the National Park Service said. The sleeping bag in which the remains were found was inside a tent, and discovered with it were multiple items, including binoculars, a day hiker pack, a shoulder bag, a folding saw, a blanket and winter gear, according to the park service and the laboratory.

At the time, a pathologist from the medical examiner's office in Washington's King County determined the remains likely belonged to a man between the ages of 30 and 50, who had died at least six months and up to two years earlier. 

Investigators eventually learned that Serrao, who was born in December 1960, would have been in his late 30s at the time of his death. But, back then, the lack of "usable" fingerprints and other concrete evidence prevented authorities from developing leads that might have helped them uncover his identity.

His name remained unknown until recently. A breakthrough came once an anthropologist with the medical examiner's office submitted a DNA sample to Othram in 2024, according to the park service, which investigated Serrao's case alongside King County authorities and the laboratory. Using forensic genealogy — a technique that can help pinpoint living relatives of a deceased person based on the decedent's DNA — the lab was able to identify possible family members by 2025.

Investigators reached out to relatives in multiple states, including Hawaii, and eventually compared and matched DNA samples from them to the one taken from Serrao's remains.

"This case remained unresolved for nearly 30 years, but investigators never lost sight of the goal of identifying this individual and finding answers for his family," Debra Flowers, deputy chief of the park service's criminal investigative division, said in a statement. "I'm proud of the persistence and collaboration that made this identification possible, and I hope it brings some measure of closure to those who have spent so many years wondering what happened to Joseph."