An American unmasked by his DNA and his family tree more than thirty years after a double murder is about to be tried in the first trial involving this revolutionary investigative technique.
Supporters and detractors of “genealogical genealogy” are closely following the case of William Talbott, who appears from this week until the end of the month near Seattle in the northwestern United States
The 56-year-old truck driver is accused of killing two young Canadians, Jay Cook and his girlfriend, Tanya Van Cuylenborg, aged 20 and 18, in 1987. She had been shot in the head and he had been strangled, a pack of cigarettes stuck in his throat.
After decades of unsuccessful investigation, the police finally announced in May 2018 the arrest of William Talbott, who had never aroused suspicion.
“If there was no genetic genealogy, we would not be here,” said investigator Jim Scharf.
A month earlier, this method had made headlines leading to the arrest of a man suspected of being the “killer of the Golden State”, author of 12 murders and about fifty rapes in California in the years 1970 and 1980.
In both cases – and in about 70 other cases since resolved – DNA found at crime scenes has been compared to the database of a public genealogy site, GEDmatch.
On this site, people who have done DNA testing – a popular practice in the United States – can enter their genetic profile to find distant relatives and complete their family tree.
On the Canadian file, a private biotechnology laboratory, Parabon Nanolabs, analyzed sperm found on a Tanya Van Cuylenborg garment and entered this genetic profile into the GEDmatch system.
The search revealed two cousins of the suspect. An expert in Parabon genealogy has traced their family trees over several generations and has isolated one parent in common: William Talbott.
The police then put her under surveillance. One day, they recovered a cup thrown by the road and tested his DNA. It matched that found on the clothes of the young Canadian.
He claims his innocence
Since his arrest, the fifties make sure he is innocent.
“My life has been suspended for more than a year for a crime I did not commit,” he said Friday in a preliminary hearing before the Snohomish County Court.
In court documents, defense lawyers questioned the reliability of the DNA profile from the crime scene.
On the other hand, they did not ask Parabon to testify about the use of genetic genealogy. “This is not an issue for the defense,” assured AFP Vice President of the company, Paula Armentrout.
However, several voices in the legal community criticize the lack of regulation of this investigative technique, which poses a challenge to the protection of personal data.
“There are very few crime rules that can be investigated, and no clear recipe for mistakes, embarrassing or intrusive revelations,” said Elizabeth Joh, a California law professor. in a column published Thursday in the New York Times.
By submitting to a DNA test, “you also expose your siblings, your parents, your cousins, people you’ve never met and even future generations of your family,” added the academic, who suggests police to obtain “warrants” for this type of investigation.
“It was the right thing to do ethically,” said AFP founder Curtis Rogers.
Only 75,000 people have given the green light at the moment, while the police had up to one million profiles. Which, according to a study, identified nearly half of the American population.
The new database is too narrow to advance new surveys.
But in theory, nothing prevents the police from going to any genealogy site without revealing its motives, says law professor David Kaye.
“She often works undercover, and the courts allow a dose of deception,” he adds.