Unresolved Investigations | DNA banks to the rescue

Quebec police forces are interested in a major advance in genetic genealogy that has made it possible, for the first time in Canada, to elucidate the murders of two young women that occurred nearly 40 years ago in Ontario. The method could eventually be used to close old, unsolved cases in the province, but it presents several ethical issues, experts warn.

The news caused a stir in the police world earlier this week. Toronto police arrested Joseph George Sutherland in northern Ontario. The 61-year-old faces two counts of first-degree murder in the 1983 deaths of Susan Tice and Erin Gilmour.

The two women had been sexually assaulted and stabbed to death in their bed, four months apart.

To reach this conclusion, nearly 40 years after the events, the Toronto police revealed that they had used a genetic genealogy technique used several times south of the border, but still unprecedented in Canada.

With the help of Othram Inc., an American company specializing in forensic genealogy, Toronto police were able to locate Joseph George Sutherland by matching his DNA, collected from the crime scenes in 1983, with that contained in large public databases such as Ancestry or 23andMe.

Browse the family tree

Thanks to these large online banks where millions of individuals have submitted DNA in the hope of tracing their family tree, the police can locate someone in the suspect’s family, explains the professor of genetics and forensic science at the University of Quebec at Trois-Rivières (UQTR) Emmanuel Milot.

“There is a very strong chance that if we go as far as level 3^e cousin, there is a person [liée à vous] who put his DNA in a bank like that,” explains the man who also works at UQTR’s Forensic Research Laboratory.

The investigators will then go through the family tree of the individual whose DNA matches in order to find a profile corresponding to that of the suspect sought, explains the professor.

“Let’s say we’re looking for a man. All the women, we eliminate them, all the dead people, we eliminate them, or those who were not in the right region. Then when they have a limited number of potential targets, they go from there to carry out a classic investigation”, describes Emmanuel Milot, because so far the evidence remains “probabilistic”.

This “classic” investigation can give rise to tailings to collect DNA, for example by picking up a goblet in which the suspect allegedly drank before throwing it in the trash, in order to confirm that it matches the one found on the crime scene.

Spectacular results

” [La généalogie génétique] will rarely give results, but when it does, it’s spectacular,” insists Emmanuel Milot. There are no data yet on the number of cases resolved through genetic genealogy.

This method has already been used to solve several unsolved cases in the United States, including the famous case of the “Golden State killer”. Joseph DeAngelo, a former police officer, was convicted of murdering 13 people between 1975 and 1986, and of committing dozens of burglaries and kidnappings.

The Sûreté du Québec (SQ) and the Service de police de la Ville de Montréal (SPVM) did not return our request on Tuesday to find out if they were interested in the method of genetic genealogy in order to elucidate files not resolved.

Having been questioned about this method by certain Quebec police forces, Emmanuel Milot affirms, however, that some of them are interested in it given its impressive results. “Given the successes it has had, they definitely have that in mind,” he says.

Ethical issues

However, the use of genetic genealogy for criminal investigation purposes raises several issues.

First, DNA evidence alone is not enough to convict a criminal, underlines criminal lawyer Marie-Hélène Giroux. “With a simple DNA match, is that scientific proof that is infallible as things stand? No,” she snaps.

Investigators must therefore collect circumstantial evidence to support their case, for example by demonstrating that the suspect was in the vicinity at the time of the crime.

Family ties could also be revealed inadvertently, not to mention the notion of consent linked to the registration of one’s DNA in a public genealogical bank, lists for his part Emmanuel Milot, speaking of “the tip of the iceberg”.

Sooner or later, governments will have to form ethics committees to establish guidelines around this method, especially given its promises, believes criminal lawyer Marie-Hélène Giroux.