Montreal·CBC Explains

A new DNA tool helped crack a Montreal cold case. It could help solve others

For decades, detectives and Sharron’s family searched for her killer, with no luck. Thanks to new DNA testing tools, they now know he was Franklin Romine — an American who’d been living in Montreal at the time of the murder.

For decades, nobody knew who killed Sharron Prior

young blond girl smiling at camera in film photo
Sharron Prior, 16, was last seen March 29, 1975. DNA taken from the remains of Franklin Romine, exhumed in West Virginia in early May, proved to be a perfect match for the DNA left at the scene by Sharron's killer. (CBC)

On March 29, 1975, the family of Sharron Prior waited for the reliable 16-year-old to come home for dinner in Montreal's Pointe-Saint-Charles neighbourhood. She never did. 

Four days later, Prior's body turned up in an abandoned lot in Longueuil, on Montreal's South Shore. She'd been savagely sexually assaulted and murdered.

For nearly half a century, her killer's identity eluded police detectives and Sharron's family.

But now, new DNA testing tools have proved conclusively it was Franklin Romine — an American who'd been living in Montreal at the time of the murder.

It is the first time that Y-chromosome analysis and genetic genealogy have been used in this way in Quebec: to solve a cold murder case. 

"It's an exciting moment for us as scientists," said Nicolas Tremblay, a forensic biologist with Quebec's national forensic lab, "to be able to bring this new technology to law enforcement officers, the justice system, but also to the families who are waiting for it, as well."

How they did it

Police chased dozens of leads and interviewed hundreds of people throughout their decades-long investigation, and Romine's name never came up. 

They did have some evidence: they had a description of the killer and a rough idea of the type of car he'd been driving. They also had some clothing left at the crime scene that would later provide traces of the killer's DNA. 

DNA is the human genetic code — it's in all our cells, and each person's code is unique.

But for decades, the DNA traces left at the crime scene weren't helpful — first, because forensic DNA analysis was in its technological infancy, and much later, once techniques advanced to the point that the DNA could be tested, because it didn't match anyone in police databases. 

In 2022, scientists at the provincial forensic lab, the Laboratoire de sciences judiciaires et de médecine légale du Québec, decided to try something new. 

They knew the DNA left at the scene belonged to a man. Biological males have what's called a Y chromosome, a piece of DNA that is passed down from father to son. 

They decided to try matching that Y chromosome to something else that was often passed from father to son: family names. 

They used a new DNA database to compare what was found at the crime scene to DNA that had already been matched to certain paternal lines.

WATCH | How scientists and Longueuil police solved this cold case:

How new DNA and genealogy methods solved a 48-year-old cold case

4 months ago
Duration 2:40
CBC explains how police finally determined beyond all doubt who killed 16-year-old Montrealer Sharron Prior in 1975 despite no new evidence being brought to their attention.

2 living brothers

Using this method wouldn't necessarily turn up an exact match, but it could give them a lead.

It worked. When they ran the killer's Y chromosome through the system, they came up with two possible paternal lines: the family name Romaine or Romine.

A 1977 mugshot of a dishevelled man with curly hair.
Police have concluded with certainty that Franklin Romine, who died in 1982, was Sharron Prior's killer. So brutal was the teen's murder that media at the time called the suspect 'a monster.' (Service de police de l'agglomération de Longueuil)

Éric Racicot, the Longueuil police detective investigating the case, determined there was a man named Franklin Romine who lived in Montreal in 1975, when Sharron was killed. 

While Racicot was tracking down Franklin Romine, genetic genealogists in Quebec were tracing Romine's family tree using data provided voluntarily to ancestry sites, to connect it to the crime scene DNA.

They found that Franklin Romine had died in 1982, but he had two living brothers — both of whom later agreed to provide a DNA sample. Romine's brothers also said Franklin was a violent man who had a history of sexually assaulting women. 

One of them spontaneously told police that his brother "probably did kill Sharron," according to Racicot.

DNA from Romine's brothers confirmed Racicot's suspicions — Franklin was likely the killer. 

Finding closure

As the Longueuil police detective began connecting the dots, he felt a spark of excitement. Racicot said he realized  he was closing in on a murderer who had remained in the shadows for decades. 

At first, he couldn't quite believe it.

"That's when you have to rely on technology, and as you can see, it really works."

Yvonne Prior held a missing poster of her daughter Sharron in 2012, found dead 37 years prior in Longueuil.
Yvonne Prior holds up a missing poster of her daughter in 2012, 37 years after Sharron Prior was found dead in an abandoned lot in Longueuil, on Montreal's South Shore. (CBC)

The evidence led the authorities earlier this month to authorize the exhumation of Romine's bones to be tested. 

When the results came in, there was no longer any doubt: the remains' DNA was a perfect match with the DNA found at the crime scene.

The news gave Sharron's family some measure of closure. 

"The solving of Sharron's case will never bring Sharron back," said Doreen Prior, one of Sharron's younger sisters, at a news conference. "But knowing that her killer is no longer on this earth and cannot kill anymore brings us to somewhat of a closure."


Matthew Lapierre is a digital journalist at CBC Montreal. He previously worked for the Montreal Gazette and the Globe and Mail. You can reach him at