Genetic genealogy helped identify the youngest known victim of one of the nation’s most prolific serial killers almost 37 years after her remains were discovered near a baseball field south of Seattle.

Wendy Stephens was 14 and had run away from her home in Denver before Gary Ridgway, the Green River Killer, strangled her in 1983, the King County Sheriff’s Office announced Monday.

Ridgway terrorized the Seattle area in the 1980s, and since 2003, he has pleaded guilty to killing 49 women and girls. Four of the victims — including Stephens — had not been identified.

“Ridgway’s murderous spree left a trail of profound grief for so many families of murdered and missing women,” King County Prosecutor Dan Satterberg said in a written statement. “We are thankful that Wendy Stephens’ family will now have answers to their enormous loss suffered nearly 40 years ago.”

Researchers at the DNA Doe Project, a volunteer organization that uses publicly available DNA databases to find relatives of unidentified victims, helped make the identification.

Genetic genealogy has increasingly been used to track down unidentified criminal suspects and help solve scores of cold cases in recent years, some of them more than a half-century old or involving other serial killers. It unmasked the Golden State Killer, Joseph DeAngelo, who pleaded guilty to 13 murders and 13 rape-related charges that spanned much of California between 1975 and 1986.

Stephens’ remains were found in a wooded area next to a baseball field in what is now the suburb of SeaTac on March 21, 1984, after the groundskeeper’s dog came home with a leg bone. She had been killed a year or more earlier, investigators believe, and she is thought to have been Ridgway’s youngest…