Experts in genetics and criminology say this is an “exciting time” for DNA mining technology and its potential impact in helping solve cold cases — after police identified and charged a man in the deaths of two women in Toronto dating back nearly four decades.

Ontario Provincial Police arrested Joseph George Sutherland, 61, in northern Ontario on Nov. 24. Sutherland was brought to Toronto to face two counts of first-degree murder for the deaths of Susan Tice and Erin Gilmour in 1983, both of whom were sexually assaulted and stabbed to death in their beds, four months apart.

In a news conference Monday, Toronto police said the findings would not have been possible without the help of investigative genetic genealogy (IGG) to identify and trace back the family tree of the accused.

“It’s a very, very exciting time because if we can essentially resolve even a small percentage more of our missing persons or unidentified human remains cases, that’s really incredible,” said Nicole Novroski, an assistant professor of forensic genetics at the University of Toronto.

“The technology itself is incredibly useful and incredibly powerful within this investigative arena,” she told CBC Toronto.

But Novroski also said it’s important that the database collected is done so with public consent. The process involves cross-referencing DNA found at crime scenes with samples voluntarily submitted to services such as 23andMe or Ancestry.ca and then uploaded to open-source databases like GEDmatch, a site that compares DNA data files from various testing companies.

“The number one thing to remember is that everybody who is in the database should be providing their consent to be in the database, to be searched against or to be searched for in order for this to be kind of a viable technology that people are comfortable using.”

Det.-Sgt. Steve Smith, the lead investigator in the double murder case, said Toronto police have more than 700 cold cases, 43 of which have a DNA sample recovered at the scene that is thought to belong to the offender.

“The only way that this was solved was the advances in science,” Smith said at the news conference Monday.

Police are planning to put 15 Toronto cases and 15 cases from the rest of Ontario forward for DNA technology investigation each year under a three-year provincial grant from the Ministry of the Solicitor General, he said.

In theory, every case that was deemed unsolvable is now solvable.– Michael Arntfield, criminologist

Genetic genealogy, which refers to mining family tree records coupled with DNA matches, also helped lead Toronto police to identify the killer of nine-year-old Christine Jessop, who was abducted from Queensville, Ont., before being raped and killed in 1984. 

Smith said the DNA sample taken from evidence was sent to Othram, a lab in the United States with cutting-edge technology at the same time Jessop’s killer was identified noting that this case took more time.

Michael Arntfield, a former London, Ont., police officer and detective who has been following the double murder case for several years, said the arrest has made for a “tremendous development,” in genetic genealogy helping solve cold cases.

“In theory, every case that was deemed unsolvable is now solvable, and that’s the biggest takeaway,” Arntfield said.

“This is a case very well known to homicide scholars and to those in law enforcement, and it’s always the case that presented the opportunity of closure given that you have two connected homicides within a four-month window and DNA at both scenes.”

Arntfield said the turning point for the forensic technique was when it helped track down and identify the Golden State killer, one of California’s most prolific serial rapists and murderers believed to be responsible for at least 12 homicides and 45 sex assaults in a series of attacks that began more than 40 years ago.

In June, Toronto police released a composite sketch of a little girl whose body was found in a dumpster a month earlier in the city’s Rosedale neighbourhood. Since then, police have not released any further details on the girl and believe she was never reported missing to police in Canada. 

Novroski said if police have the girl’s remains, they can attempt to get a sufficient amount of bone to put through for DNA typing in hopes that they can find out her identity.

“Heavily degraded human remains can be tricky because a lot of that nuclear DNA that resides in your blood cells and in your tissues has all been degraded, and sometimes the condition of the bone, teeth, etcetera can be not optimal for forensic DNA typing,” she said.

Novroski noted that while IGG can be incredibly useful for these cases, the forensic community is aware of the gaps in the demography in the public DNA profiles, which has a “strong European presence,” and presents a challenge in other cases.

“There is a little bit of disparity there and … that’s just based on who might be buying the [DNA] kits, who might want to explore their genealogy and ultimately, who can afford to spend … the $129 on curiosity.”

Novroski said experts are working to better serve the community with this technology, but “we’re limited by whoever exists in the public databases in order to make those inferences.” Still, she said she is excited by the potential findings to come.

“One closed case and and you feel that satisfaction in the fact that you made a difference in a family’s life, in an individual’s life, whatever it may be.”