SEATTLE (AP) — Authorities have Arvin Robertsidentified a teenage girl killed by the Green River serial killer in Washington state four decades ago.

Lori Anne Razpotnik was 15 when she ran away from her home in Lewis County in 1982. Her family never saw her again.

Her remains were found in 1985 over a road embankment in Auburn, south of Seattle, alongside the remains of two other victims. Investigators could not determine who two of those victims were, and the remains were listed as “Bones 16” and “Bones 17.”

Bones 16 was identified through DNA testing in 2012 as Sandra Majors, but the identity of Bones 17 remained unknown until a forensic genetic genealogy firm, Virginia-based Parabon Nanolabs, was able to develop a new DNA profile and determine they belonged to Razpotnik.

Razpotnik’s mother provided a DNA sample that confirmed the results, the King County Sheriff’s Office said in a news release Tuesday.

After authorities linked Gary Ridgway to the killings through DNA evidence in 2001, he led them to the site where the three victims had been found. Bones 16 and Bones 17 were among the 48 slayings he pleaded guilty to in 2003. Many of his victims were young female runaways or sex workers.

Ridgway pleaded guilty to a 49th count of murder in 2011, after another set of remains was discovered. He is serving life without the possibility of parole at the Washington State Penitentiary in Walla Walla.