'It's just astounding': Genetic genealogy credited with helping solve cold cases

The genetic genealogist who helped investigators identify the suspect in the 30-year cold-case double homicide of a B.C. couple says the new DNA technology can help more families looking for answers.

A genetic genealogist uses DNA to build and expand a family tree in conjunction with genealogical records

A poster seeking information around the 1987 double homicide of Saanich couple Jay Cook, 20, and Tanya Van Cuylenborg, 18. (CBC archives)

The arrest in the cold-case double-homicide of a B.C. couple has shone a spotlight on a new DNA technology that could help solve other cases.

The process, known as genetic genealogy, uses DNA testing to build and expand a family tree in conjunction with traditional genealogical records, such as census and vital records. 

The technology was used in the arrest of the Golden State killer earlier this month and appears to be increasingly used in criminal investigations. 

CeCe Moore is the genetic genealogist who helped authorities map and analyze the DNA evidence that resulted in the arrest Friday of William Earl Talbott II.

Talbott, 55, was arrested for the murders of Saanich, B.C. couple Jay Cook, 20, and Tanya Van Cuylenborg. 18. They were last seen alive Nov. 18, 1987.

"I do hope we will be able to continue to do it because we can help so many families," Moore said on CBC's All Points West.

Jay Cook and Tanya Van Cuylenborg of Victoria were killed in Washington state in 1987. (Crime Stoppers)

DNA file uploaded online 

Moore worked on the case with Parabon Nanolabs, a Virgina-based genetics company. 

The lab used a DNA sample collected from the crime scene in the 1987 Cook-Van Cuylenborg slayings. 

It uploaded the data from that sample to a free, open-source genealogy website called GEDMatch, which helps people find relatives.

The lab compared its file with about a million other people who have uploaded their genetic data to the site.

Two close matches were found from people who married and produced only one son, Moore said.

Genealogy experts were able to identify Talbott's family tree and work backwards to identify him as a suspect. (Snohomish County Sheriff's Office)

Once genealogists made the connection, police acquired a DNA sample from a cup Talbott had used.

Moore said she's "highly confident" Talbott is the only suspect. 

Ethical, privacy concerns

The technology is effective, but it's rife with ethical and privacy concerns. 

People who upload their genetic data to GEDmatch aren't necessarily consenting to police combing through their information.

Moore said the widespread coverage in the Golden State Killer case means GEDmatch users are likelier to know their information isn't private.

Van Cuylenborg's brother, John, said supporting DNA databanks for police purposes should be vital for the general public.

"When you look at the greater good and the benefit to society, I certainly feel that the use of these databanks is entirely appropriate and should make our communities a safer place for everyone to live," he said.


With files from CBC's All Points West and The Canadian Press