This case is the first genealogical genealogy arrest to go to trial

"We have never given up hope of finding the killer of Jay and Tanya," said Snohomish County Sheriff Ty Trenary. "The arrest yesterday shows how powerful it can be to combine new DNA technology with the relentless determination of the detectives."

But none of these cases has yet resulted in a criminal trial.

Talbott pleaded not guilty and the jury selection of his trial began Tuesday. His lawyer told CNN that Talbott had not committed the killings and that the DNA evidence did not prove it.

"The detectives and the media have developed a tunnel vision based on DNA, forgetting the fact that there is no other link between Mr. Talbott and the victims," ​​he said. said lawyer Rachel Forde in an email.

Random and Wild Assassinations

The murders of Cook, 20, and Van Cuylenborg, 18, were "as random as they are wild," prosecutors said in an affidavit of probable cause.

On November 18, 1987, the two men left Saanich, British Columbia, Canada, driving the Cook family van, police said. Their plan was to take two ferries and collect furnace parts for Cook's father in Seattle, then return to Canada the next day.

But when they did not come back as planned, their parents filed statements of missing persons.

Less than a week later, Van Cuylenborg's partially naked body was found in a ditch in Skagit County, with only one shot in the back of the head, police said. An autopsy revealed sexual assault and samples taken in his private areas contained semen, according to court documents.

On November 25, police found their abandoned van in a parking lot near Bellingham. Inside, there were inside pants with traces of sperm.

A day later, Cook's body was found under a bridge in Snohomish County. A string of plastic string and two red dog collars were stuck to the head, pebbles fell on his head and a pack of cigarettes "Camel Lights" was stuffed into his mouth, according to court documents.

The DNA of the suspect from Van Cuylenborg's body and his trousers was not Cook's. He was therefore dismissed as a suspect. The investigators later added this DNA to CODIS, the FBI's national DNA database, and to an Interpol database, but no correspondence was made with anyone, according to court documents.

The case was then settled despite the investigative power of three counties and two countries.

Genetic genealogy leads to arrest

It will take another 30 years before investigators get a break in the case.

In 2017, investigators contacted Parabon Nanolabs, a DNA technology company, who used the suspect's DNA to provide a physical description of the color of his hair, skin and eyes .

But the Golden State Killer case has opened the door to a new type of analysis called genetic genealogy.

Genetic genealogists can then use obituaries, birth certificates, public documents and social media to create a family tree and identify possible suspects.

Police said that Talbott, who worked as a truck driver, lived in the area near the scene of the killings.

With this lead, the investigators followed Talbott and retrieved a cup of coffee that had fallen from his truck, according to an affidavit. The DNA of the cup matches that of Van Cuylenborg, and he was later arrested in Seattle, police said.

The authorities praised Parabon's genetic genealogy work by announcing the arrest last May.

"We would not be here without the persistence of detectives in our office and in Snohomish County, and without the valuable support of Parabon," said Skagit County Sheriff Will Reichardt.

Defense Criticizes "Tunnel Vision" of DNA

But this will be the first time that genetic genealogy will lead to a trial. It was possible that Moore had to testify about the work of the company, but the prosecution and the defense reached a stipulated agreement that excluded him.

Instead, a cold detective will summarize the genetic genealogy and DNA work that led the investigators to focus on Talbott.

The result of the trial may ultimately be less about the future of genetic genealogy than about the circumstances of that particular case.

"The presence of DNA on the bottom of the victim does not tell us who killed her and why, and that does not tell us anything about the murder of the male victim," said L & # 39, defense counsel, Forde.