How a DNA tech and a genealogy database are helping solve decades old crime

After decades of unsuccessful searching, Seattle police finally arrested Talbott in May 2018, although he had not raised suspicions until then.

Business Standard : A truck driver implicated by his DNA and family tree in a double murder more than 30 years after the crime will face trial this week in the first case using a revolutionary investigative technique.

Supporters and critics alike of "genetic genealogy" -- the technique used to identify the suspected "Golden State Killer" by making DNA matches with his distant relatives -- have followed the case of William Talbott II, who will appear in court starting this week in Seattle.

The trucker is accused of killing two young Canadians, Jay Cook, 20, and his girlfriend Tanya Van Cuylenborg, 18, in 1987. Cook was suffocated to death, with a pack of cigarettes stuffed into his throat, and Van Cuylenborg died of a gunshot wound to the head.

After decades of unsuccessful searching, Seattle police finally arrested Talbott in May 2018, although he had not raised suspicions until then. "If it hadn't been for genetic genealogy, we wouldn't be standing here today," said Snohomish County detective Jim Scharf, who led the investigation.

Genetic genealogy first made headlines a month prior to Talbott's arrest after it was used to find the suspected "Golden State Killer," who is blamed for 12 murders and more than 50 rapes dating back to the mid-1970s.

In both cases -- as well as at least 70 other cases that have been solved since -- DNA found at crime scenes was compared to the database at GEDmatch, a free genealogy website.

The website allows users to post DNA test results and then generates a list of people with similar genomes, enabling users to find distant relatives.

For the two Canadians, private biotechnology laboratory Parabon Nanolabs analyzed sperm found on Tanya Van Cuylenborg's clothing and entered the resulting genetic profile in the GEDmatch system.

The search produced two of the suspect's cousins. One of Parabon's genealogical experts rebuilt the family trees back several generations and isolated a common relative: William Talbott.

Police officers put Talbott under surveillance and were able to retrieve a cup he threw away. When they tested his DNA, it matched what they had found on Van Cuylenborg's clothing.