Thirty-one years later, Gilmour’s killer remains unidentified. Though a DNA test in 2000 connected her murder to that of another woman who was raped and killed a few months earlier in 1983, no one has any real clue who carried out the murders. The killer remains either at large or in prison somewhere, evading prosecution for these two brutal crimes — and perhaps others.

Unsolved misdeeds like these are receiving a lot of attention these days — with a focus on the people trying to solve them. Strangely, those people aren’t cops. Deborah Halber’s book, The Skeleton Crew, just released this month, delves into the lives of amateur investigators who pursue cold cases for the thrill of solving puzzles about missing persons. And the TNT show Cold Justice follows the pursuits of two former law enforcement officials — an ex-prosecutor and an ex-crime scene investigator — who pursue justice for forgotten victims.

But in Toronto, where Erin Gilmour was killed 31 years ago, it’s not freelancers going after cold case justice — it’s police themselves. The Toronto Police Service (TPS) has devoted a small team of detectives and analysts to identifying new leads in long forgotten crimes. "No matter how long it takes," the cold case team’s website ominously declares, "we will catch you."

Earlier this year, TPS got some attention for using Twitter as a way to identify potential perps in old cases. More recently, its team leader, Detective Sargeant Brian Borg, announced the team is experimenting with new technology that's able to take DNA swabs from old crime scene evidence and turn them into police sketches of possible perpetrators.

TPS is a rare instance of a major police department devoting resources to old crimes. Part of the reason why freelancers feel compelled to take on cold cases in most major cities in the United States is that police officers are busy enough trying to solve new cases; they typically don’t have time to retrace steps in cases that have long stacked up.

Detective Borg is pragmatic about this fact. "Toronto, all things considered, is a very safe city," he tells The Verge. The cold case push is a matter of resources more than anything else, he says. Toronto is a city with a slightly larger population than Chicago and the murder rate of somewhere much smaller like Lincoln, Nebraska, which means that TPS has the resources to put detectives on cold cases. So TPS has the resources to put detectives on cold cases.

But that’s not to say Borg and his team have an easy job ahead of them. A cop for 34 years, Borg just took over the cold case team in January. Since 1921, there have been about 550 unsolved murders in Toronto, he tells The Verge.

Most cases are solved, he says — "about 80 percent" — but the rest slowly fall to him and his team. He says there’s no worldwide standard for when a case is defined as "cold," but that in Toronto, it’s defined as a case that’s "older than two years, plus the current year." So cases from 2012, 2013, and 2014 are managed by homicide detectives. Cases from 2011 and back are his responsibility.

And there’s a lot of responsibility there; Borg’s got 550 cases to solve. "It’s not easy," he says. "Not a day goes by when we don’t hear from a mother or sister or brother wondering where the progress has gone — if anywhere — in the case of their deceased loved one." But it’s not like his team can just pick a random cold case from 1921 and begin re-investigating. That would take forever — going one by one. So Borg and his team try to insinuate new leads into the process. "We look at these cases from the perspective of new opportunity," he says.

That’s how TPS’s new DNA system got its start.

In the 1990s and early 2000s, Borg explains, DNA evidence from Toronto’s cold cases were run through the laboratory connected with TPS crime investigations. The findings were then cross referenced with the Royal Canadian Mounted Police’s "DNA Data Bank" — Canada’s federal repository for DNA info collected at crime scenes. Some of that evidence ended up leading to new convictions. But in most cases, the DNA collected from crime scenes didn’t match anyone from the Data Bank. So these cases were back at square one.

Borg hopes that's about to change. TPS recently partnered with two US partners — AKESOgen, a genomics company; and Identitas, a DNA profiling company. Neither of these companies have worked with police before, Borg says, but they say they’ll be able to do something unique with TPS’s cold case DNA evidence: create police sketches. If all goes as planned, Borg says TPS will be able to pinpoint ancestral information, hair color, eye color, and ethnicity of the people whose DNA evidence was found at murder scenes years ago.

"No forensic laboratory uses the technology we’re using here," he says. "It’s been used in technology and medicine, never before by police."

Will it work? "The jury’s still out," Borg says. TPS expects it’ll receive its first test cases back from its US partners in upcoming weeks. But it’s worthwhile to experiment. He didn’t say how much TPS is shelling out for the test cases, but he says the program’s sustainable; if it goes well enough, he says TPS will look into how they might do cold case DNA mapping in-house.

"If this gives us the ability to solve a case [like Erin Gilmour’s], it’s worth the attempt," he says. "And if it is seen as a good thing, this could change the way police departments around the world solve cold cases going forward."