This is the end of Marc-André Grenon’s legal saga, more than 20 years after his crimes. The man who killed student Guylaine Potvin in Jonquière in 2000 withdrew his appeal against his conviction on Friday. He also pleaded guilty Friday in the other case for which he had been pinned, namely of having attacked and left for dead a student from Quebec City the same year.
“We are very, very satisfied with this outcome,” declared by telephone the Crown prosecutor who was leading the two cases, Mr.e Pierre-Alexandre Bernard. The lawyer recalled that Grenon was arrested 22 years after his crimes, which had kept the police busy all these years.
“It puts an end to the Grenon saga. »
Last February, the 49-year-old man was found guilty by a jury of the first-degree murder of Guylaine Potvin, 19, as well as her sexual assault. For his crimes, he was sentenced to life in prison, with no possibility of parole for 25 years.
The young woman’s lifeless body was found on April 28, 2000, in her apartment in Jonquière. His face, like his body — found practically naked — bore marks of violence. Grenon had entered her home during the night while she was sleeping alone in the apartment. He sexually assaulted her and strangled her to death.
At the end of his trial, his lawyers appealed the guilty verdict, rendered by the jurors in less than an hour.
But on Friday, the man who was called “cowardly, sexually depraved and a murderer” by the trial judge, filed a notice of withdrawal with the Court of Appeal, which closes the case.
Other crimes
About two months after the murder of Guylaine Potvin, Grenon did it again: he has since been accused of attacking another young woman in the Sainte-Foy district of Quebec and leaving her for dead. However, the student survived.
For more than 20 years, Grenon evaded justice. But advances in science and new investigative methods in forensic biology finally allowed the police to catch him, in Granby, in 2022.
He was quickly accused of what he did to the two young women.
Grenon’s DNA was found at both crime scenes. But he did not correspond to any person listed by the police: 20 years passed without the man being worried.
PatroNYme
Then, the Laboratory of Judicial Sciences and Legal Medicine offered the Sûreté du Québec (SQ) investigation team the opportunity to join the PatronYme project, which is based on biology: the Y chromosome — only men in have a — is passed from father to son, and in the West, the surname given to a child is generally that of the father.
The laboratory’s database therefore raised lines of inquiry using the DNA collected, and the surname “Grenon” quickly found itself on the list of “priority surnames”. Then, in June 2022, the investigation turned to Marc-André Grenon. Police surveillance led to the recovery of two straws and a cup that he used at the cinema and which he disposed of in a trash can.
DNA on both straws matched that taken from the crime scene, the jury was told. Grenon was then arrested and a second sample taken confirmed this conclusion.
“It’s a societal achievement! » exclaimed Me Bernard in interview. “PatronYme is genius. »
As for the Sainte-Foy victim, Grenon pleaded guilty to attempted murder and trespassing. For these crimes committed in July 2000, he received 15 years in prison — this was a joint suggestion by the Crown and the defense.
But as he has already received a life penitentiary sentence, this second period of incarceration will be served at the same time, said Mr.e Bernard. In short, “this will not extend the period of ineligibility for parole any further”, but this other sentence could weigh in the balance if Grenon seeks to be released.