EVERETT — For three decades, the families of Jay Cook and Tanya Van Cuylenborg had only questions and fleeting memories.
On Friday morning, one long-awaited answer arrived.
A jury found William Talbott II guilty of two counts of aggravated murder in a trial that was the first of its kind.
The truck driver, 56, of SeaTac, had been identified in a pioneering investigation led by the Snohomish County Sheriff’s Office.
A genealogist used a public DNA site, GEDMatch, to help build a family tree for the suspect based on DNA from a crime scene. Her research pointed to Talbott.
Since then, dozens of arrests have been made in cold-case crimes nationwide through a forensic method known as genetic genealogy, stirring a heated debate over police use of public ancestry databases.
Many suspects, including the former cop accused of being the Golden State Killer, await trial.
Talbott’s case marked the first time that the technique had gone before a jury.
Other than semen at two crime scenes, little else tied the defendant to the killings. His defense argued the semen was the result of a consensual act.
He grew up seven miles from a third crime scene south of Monroe, where Jay Cook had been bludgeoned with rocks, strangled with twine and left dead under a bridge in 1987.
Talbott did not testify.
He walked into the courtroom Friday dressed in dark gray. After a law clerk read the jury’s verdict — guilty as charged — he flinched and gasped.
“No,” he said, quietly. “I didn’t do it.”
Moments later his head lolled back and forth, as his attorneys put their hands on his neck and back.
Jail guards pushed him out of the room in a wheelchair.
Family and friends of the victims embraced.
Judge Linda Krese set sentencing for July 24. There is only one possible sentence: life in prison.
“While the main interest on this case has been focused on the use of genetic genealogy, we’ve been trying to find a killer,” said Capt. Rob Palmer, head of investigations for the Snohomish County Sheriff’s Office, after the verdict. “It’s an amazing tool, and we’ll be using it again.”
Added Laura Baanstra, the sister of victim Jay Cook: “This would not have been solved if it had not been for the DNA evidence. The use of GEDMatch — I hope more and more people will be willing to allow their DNA on these sites so that this world can be safer.”
“Our family is very grateful for all the people that helped bring this to fruition,” said John Van Cuylenborg, brother of Tanya Van Cuylenborg. He thanked the Snohomish County Sheriff’s Office and its cold case team, as well as those involved in the genetic genealogy analysis that led to Talbott’s arrest.
Jay and Tanya
Cook stood a stalky 6-foot-4.
At age 20, he hadn’t beefed out.
He’d learned to play rock ’n’ roll bass guitar with friends in his hometown on Vancouver Island.
He worked at a pizza parlor for a while. One night after a shift, he rode his bike three hours through rain and darkness to a cabin where friends were staying for a weekend, balancing a pizza the whole way to bring them food, recalled his sister.
Caleb Hutton: 425-339-3454; firstname.lastname@example.org. Twitter: @snocaleb.