Last October, in a Quebec courtroom, Sylvie Desjardins delivered a message 30 years in the making to her daughter's killer.
“You thought you were taking your own life, but in fact you only added weight to your existence,” she told killer Real Courtemanche.
“You will carry this silence, this emptiness, this gaze extinguished by you until your last breath.”
For decades, the murder of 10-year-old Marie-Chantal Desjardins north of Montreal haunted investigators and her family. Her beaten body was found in 1994 on her bicycle leaning against a nearby tree, four days after she returned home from a friend's house.
The case culminated this year with Courtemanche's conviction for second-degree murder. It was one of several high-profile murders in Quebec that have recently been solved thanks to advances in DNA testing, techniques that offer hope of solving not only colder cases but also active ones, says the head of the province's DNA crime lab.
While police are coy about the exact strategies used to identify the killers, the judge in Desjardins' case said “scientific advances and major breakthroughs in forensic biology” allowed Courtemanche's DNA to be identified from crime scene evidence.
Diane Seguin, who heads the DNA unit of the province's crime lab, the Forensic Sciences and Legal Medicine Laboratory, says her team analyzes about 50 unsolved cases a year and has helped police solve eight to 10 in the last year or two.
She said the resolution of the cases was made possible by improved methods of DNA extraction and genetic genealogy – comparing DNA from crime scenes to publicly available DNA databanks consisting of profiles uploaded by members of the public researching their family roots.
“I'm optimistic … the more people who put their DNA in these jars and agree to participate in forensic investigations of human remains, the more matches and investigations that will be solved,” Seguin said.
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Cold cases are just a small part of the lab's work, which processes 30,000 to 40,000 pieces of evidence each year. Based on this evidence, 4,000 to 5,000 DNA profiles are uploaded to a national DNA database called the Crime Scene Index.
In both cold and active cases, the first step is to upload a DNA profile obtained from crime scene evidence into a national database to see if it matches the DNA profile of a known convicted criminal, Seguin said.
She said the lab sometimes takes DNA samples from decades-old evidence that has never been tested before, or extracts a new profile using modern, more sensitive equipment. The surge in the number of profiles in the database makes identification more likely, she said.
Seguin says the lab also conducts “patronymic studies”—running unknown DNA through a database that links profiles to surnames. Although this process is not perfect, it can sometimes link a DNA profile to a surname.
If investigators find a match between crime scene evidence and a DNA sample uploaded to a public website (even if the match only identifies a distant relative of the suspect), investigators can begin to build a family tree using genetic genealogy.
In September, the method was used to identify the killer of 26-year-old Catherine Daviau, who was killed in her Montreal apartment in December 2008. A DNA sample at the scene was linked to profiles in public databases, police said.
This ultimately allowed investigators to focus on Jacques Bolduc, who died in 2021 in prison while serving an unrelated sentence. The investigation determined that Bolduc did not know the victim, but responded to an online ad she posted for the sale of his car.
Seguin emphasizes that genetic genealogy results provide only the equivalent of a lead that can be given to police to narrow the investigation—officers must gather more evidence.
In the future, she hopes to use genetic genealogy in more proactive cases to prevent crimes from being solved. “So if someday, for example, we have a series of sexual assaults and the person is unknown … they could commit another (attack),” she said. “So it’s good to work on cold cases, but it’s also good to work on contemporary cases to prevent other attacks.”
She said members of the public who want to help solve cases can do so by uploading their DNA profiles to the databases the lab uses — FamilyTreeDNA or GEDmatch — and granting permission for them to be used by law enforcement.
Quebec provincial police say advances in DNA testing allowed them to arrest a suspect in September and charge him with manslaughter in a 1979 home invasion in Causapscal, Quebec. And in July, police were able to prove that a body found in 1997 on PEI was that of a Quebec man who had gone missing the year before.
In September, police in Gatineau, Quebec, announced an arrest in connection with the 2011 murder of 18-year-old Valerie Leblanc, who was found in the woods near a college campus after suffering what a coroner said was a skull fracture from a blow to the head. Police said it was due to “new investigative techniques” but declined to say whether they included DNA.
While some experts such as Seguin are pushing to expand the use of genetic genealogy, Michael Arntfield, a criminologist at Western University and a former police detective, says there is also a push to make the method obsolete.
He says some groups, including the Canadian Association of Chiefs of Police, are advocating for expanded crimes that require the offender to upload their DNA to a national data bank; Currently, only a few serious crimes are included in this list. This raises civil rights and privacy issues, Arntfield said, but will also help solve crimes much faster.
“As this technique grows in popularity, there will come a time when you can almost abandon the term 'cold case' because, especially if it's used in live-action murders, it will never get to the 'cold case' stage,” he said.
