Killer convicted using genetic genealogy in Snohomish County up for sentencing

A Snohomish County jury found William Earl Talbott II guilty in June for the 1987 murders of a young couple from Victoria, British Columbia.

Barring a successful appeal filed by Talbott's defense attorneys, he'll be sentenced Wednesday to life in prison without the possibility for parole.

It's the only sentencing option for aggravated murder since the Washington State Supreme Court found the application of the death penalty unconstitutional.

The brutal murders of 18-year-old Tanya van Cuylenborg and 20-year-old Jay Cook stumped investigators for decades.

Even after advances in technology, DNA recovered from van Cuylenborg's body was never matched to any criminal database. The case drew national attention last year after investigators partnered with a company that uses genetic genealogy to solve crimes.

Using the crime scene DNA and a public DNA database a genealogist found two of Talbott's second cousins. From there she created a reverse family tree that lead to Talbott.

After a nine-day trial a Snohomish County jury deliberated two days before finding Talbott guilty of two counts of aggravated murder.

Talbott has maintained his innocence. During the trial his attorneys argued Talbotts’s DNA was a result of consensual sex.

Talbott's appeal will be heard before the sentencing on Wednesday.