Blue Line

Quebec suspect in decades old murder and sex assault may have other victims: police

October 14, 2022  By The Canadian Press

Oct. 14, 2022, Montreal, Que. – A man charged this week in connection with a murder and separate sexual assault 22 years ago is suspected by police of having other alleged victims.

Marc-Andre Grenon, 47, was charged Thursday with first-degree murder and aggravated sexual assault in the death of Guylaine Potvin, 19, in April 2000. He was also charged with attempted murder and aggravated sexual assault in connection with a violent attack that occurred about 200 kilometres south, in Quebec City, in July 2000.

Provincial police are investigating Grenon within a “serial crimes management structure,” spokeswoman Sgt. Beatrice Dorsainville said in an interview Friday. That type of operation, she said, allows various police forces to pool resources to identify predators.

“Given that we’re talking about the same suspect alleged to have committed the same type of crime on similar victims, this is why the management structure for serial crime investigations was deployed,” Dorsainville said.


Potvin was found dead on April 28, 2000, in her apartment in Jonquiere, now a borough of Saguenay, Que., north of Quebec City. She lived with two female roommates, also students, who were not home when the killing took place inside their Panet Street residence.

In the Quebec City case, the victim – also a college student who lived alone – was left for dead in her apartment but survived. A court-ordered publication ban protects her identity.

More than two decades later, Quebec provincial police arrested Grenon on Wednesday in Granby, Que., east of Montreal. He appeared by video on Thursday in courtrooms in Saguenay and in Quebec City. Grenon remains detained until his next court appearance on Nov. 21.

Provincial police said Friday in a statement there could be other crimes connected to Grenon, and they released photos of the suspect over the years so that other potential victims may recognize him. “The investigation tends to show that the suspect could have had other minor or adult victims,” the police said.

Dorsainville said it’s possible there could be victims in different parts of the province – between 1993 and 2022, Grenon lived in Quebec’s most populous regions, including Saguenay, Lac-St-Jean, Quebec City and the greater Montreal area.

“The investigation is ongoing, so we’ll see where it will go,” Dorsainville said.

Grenon’s arrest is the first made by the police’s cold case squad since it was beefed up with more resources in 2018.

In a statement on Wednesday, provincial police praised the work of investigators in the cold case division and the forensic science laboratory and “the innovative methods used today in forensic biology” that allowed for an arrest. They did not provide details, however, on which techniques were used.

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