Police set up a command post in the town, north of Laval, hoping that someone will come forward with new information.
Investigators say they are looking to speak to anyone who lived in the same neighbourhood as Laverdière in 1989, anyone who knew Laverdière and anyone who might have noticed something out of the ordinary around the time the woman was killed.
Sûreté du Québec Sgt. Benoît Richard said many people were questioned at the time of Laverdière's death, but no one was arrested.
Modern tests yield new clues
Some items that didn't belong to the woman were found in her apartment.
"We have some new ways to look at those things that were seized," said Richard. "We're trying to get people to come and talk to us, to see if we can link those things with somebody."
For Laverdière's mother, seeing her daughter's case reopened is painful, but it brings new hope as well.
"When you have kids, and you're close, and you speak to them every day, then suddenly there are no more phone calls, and you wait but know there will never be any calls again — it's not easy," Janine Couturier said.
"I'm asking people, no matter how small the information may be that you have, please, as Sylvie's mother, I would like you to call."
Laverdière's disappearance was noted after she failed to show up at a Rosemère gym, where she worked as a manager.
Her body was found in her basement apartment on April 18, 1989. She had been sexually assaulted and strangled.
Her purse was found 2.5 kilometres from her apartment, on Ste-Thérèse Road, near Highway 640.
Anyone with information about Laverdière's murder is asked to call police at 1-800-659-4264.Suggest a correction