The trial of Marc-André Grenon for the murder of Guylaine Potvin began Monday morning with jury selection at the Chicoutimi courthouse, nearly 25 years after the death of the 19-year-old student.
She was found murdered at home, in her apartment in Jonquière on April 28, 2000. Her undressed body showed signs of violence. Biological fluids – containing DNA – were taken at the time, but the profile of the attacker was then unknown to investigators.
All these years, the murderer was at large. Then, in October 2022, Grenon was arrested in Granby by investigators from the Disappearances and Unresolved Files Division of the Sûreté du Québec (SQ).
The man, now 49, has been charged with sexual assault and murder.
Monday morning, in the crowded courtroom, he pleaded “not guilty” in a weak voice to the two charges against him. Like all accused, he is presumed innocent until proven guilty.
Genetic analysis
His trial should reveal how the police managed to identify the alleged murderer and attacker, so many years after the crimes. At the time of the man’s arrest in 2022, the SQ had mentioned the use of “new investigative methods in forensic biology”, without giving further details.
Monday morning, Superior Court Judge François Huot, who will preside over the case, told prospective jurors that at a certain point, the surname “Grenon” became a priority in the investigation. During a police operation targeting him, police recovered two straws that he had “used and abandoned”. An analysis showed that it was the same genetic profile as that taken from the crime scene in 2000, he said.
On Monday, the first stage of the trial took place, the selection of the 14 jurors who will hear this case. When this step is completed, the Crown will be able to begin presenting its evidence. The Crown prosecutor, Mr.e Pierre-Alexandre Bernard announced that he was going to call 11 witnesses.
The trial for the murder of Guylaine Potvin is expected to last five weeks.