EVERETT, Wash. — A jury in Snohomish County has found a man guilty in the 1987 double murder of Jay Cook and Tanya Van Cuylenborg.
Investigators linked him to the decades-old murder case using genetic genealogy.
William Earl Talbott II was convicted of two counts of first-degree murder with aggravating circumstances.
Talbott killed Cook, 20, and Van Cuylenborg, 18, a Canadian couple who disappeared on a road trip from their home near Victoria, British Columbia to Seattle.
About a week later, Van Cuylenborg's body was found down an embankment in rural Skagit County, north of Seattle. She was naked from the waist down and had been shot in the back of the head.
Hunters found Cook dead two days later in brush near a bridge over the Snoqualmie River in Monroe - about 60 miles from where his girlfriend was discovered. He had been beaten with rocks and strangled with twine and two red dog collars, authorities said.
The couple's van was found in Bellingham near a bus station. Van Cuylenborg's pants were in it; investigators found semen on the hem, and said it matched that on her body.
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Talbott was arrested last year and charged with aggravated murder after authorities said they used genetic genealogy to identify him as the person who left his DNA on Van Cuylenborg's clothing. The practice involves identifying suspects by entering crime-scene DNA profiles into public databases that people have used for years to fill out their family trees.
Prosecutors said Talbott's partial palm print on the couple's van and the DNA evidence is proof Talbott raped Van Cuylenborg.
"Under what circumstances does the defendant end up in the back of the van for a consensual sexual encounter with Tanya? Where's Jay? What does he think about it?" asked Snohomish County Deputy Prosecutor Matt Baldock.
Van Cuylenborg's body showed no evidence of sexual assault.
There were gloves found with the abandoned van, and Talbott's attorneys said if he was the killer, he would have used them, so his hand print on the van was evidence of consent.
"At some point, Tanya had sexual contact with Bill, but we don't know anything beyond that, and that's not sufficient proof to convict a man of aggravated murder,” said defense attorney Rachel Forde.
Talbott faces life in prison.
The Associated Press contributed to this report.
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