A man who used a sword to kill two people and seriously injure five others in Quebec City's historic district on Halloween night 2020 was found guilty by a jury Friday on two counts of first-degree murder.

A jury convicted Carl Girouard, 26, in the deaths of Francois Duchesne, 56, a museum employee, and Suzanne Clermont, 61, a hairdresser. Jurors also found him guilty on five counts of attempted murder.

Girouard had admitted to the acts, but his defence lawyer argued his client was not criminally responsible due to a mental disorder and could not tell right from wrong. The Crown countered that the killings were premeditated and that Girouard was aware of his actions that night.

Minutes after the 11 jurors delivered the verdicts on Day 5 of their deliberations, defence attorney Pierre Gagnon said his client had expected a different outcome and would be appealing.

"He knows very well that this is a battle that has just ended, but there will be a sequel," the lawyer told reporters.

According to the Crown's case, Girouard drove from his home north of Montreal with a Japanese-style sword called a katana that had a 76.9-centimetre blade. He wore black jogging pants, black leather boots, a short-sleeved kimono and a black mask. After arriving in Quebec City, he drove around before finally parking in front of Le Chateau Frontenac hotel, in the city's historic quarter, and beginning his attack.

The case hinged on expert testimony from psychiatrists who presented conflicting conclusions about Girouard's criminal responsibility.

Dr. Gilles Chamberland, a psychiatrist testifying for the defence, concluded that Girouard was on the autism spectrum, suffered from schizophrenia and was delirious and in a state of psychosis the night of the killings, unable to distinguish right from wrong.

Chamberland said the symptoms were present from early in Girouard's childhood and that the accused retreated into a world of violent video games.

Girouard told the trial that by age 18, he had hatched a mission that involved killing people with a sword, creating chaos, changing the world and encouraging like-minded people -- whom he called his "alter-egos" -- to continue his "mission" after his death.

He said there were two competing versions of himself in his head, including a "bad" version who was mission-focused but had ceased to exist after the Halloween attacks. He told the court that upon arriving in Quebec City from his home in Ste-Therese, Que., he was fearful and struggled with continuing his mission. But ultimately, "bad Carl" took over, he said.

The prosecution argued that the acts were premeditated, noting Girouard had spoken to mental health workers since his late teenage years about using a sword to attack people.

The Crown's primary expert, psychiatrist Dr. Sylvain Faucher, concluded that Girouard suffered from a personality disorder and was on a "narcissistic quest" to express his resentment toward society, concluding that there were no signs of delusional thinking and the accused knew right from wrong.

Faucher said the killer was pursuing a "malicious fantasy" inspired by his imagination and the violent video games he played. His ultimate goal, the Crown expert said, was to gain notoriety. He said schizophrenia was unlikely, noting the absence of symptoms at a younger age, which typically precede the disease. He also found it unlikely that "bad Carl" simply vanished without Girouard taking any medication.

Prosecutor Francois Godin said he was happy with the verdicts.

"We're very happy for the families of the victims who, today, will be able to turn the page and we hope put some salve on their wounds," Godin said.

One of the survivors of the attack, Lisa Mahmoud, told reporters at the courthouse she wanted the maximum possible sentence for Girouard, whom she described as "very dangerous" and a "manipulator."

"I think it was the best decision to make; I thank them very much for their work. It's a good verdict," Mahmoud said, adding that she was still recovering from her wounds.

"I'm still battling with my injuries, but I'm lucky to be here. I will take my life back. I will be very relieved once the sentence is out," she said.

Clermont's sister-in-law, Marie-Claude Veilleux, said she was satisfied with the verdict, having followed the entire trial.

"Society will be protected from this very dangerous individual, but it won't bring us back Suzanne nor Mr. Duchesne," she told reporters. "But society will be protected."

Gagnon said there were serious grounds for appeal. Before the jury rendered its verdicts, the trial judge reproached the prosecution for the way it presented Girouard's five-hour police interrogation during which the accused spoke only once.

Gagnon said it was inappropriate for the Crown to suggest to jurors that Girouard's silence during the interrogation was a sign the accused knew he had done something wrong. In Canada's criminal justice system, suspects have the right to stay silent and neither judges nor jurors should infer anything from that silence.

Quebec Superior Court Justice Richard Grenier put off the case for sentencing until June 10, as the Supreme Court of Canada is to rule next Friday on the constitutionality of consecutive life sentences for people found guilty of multiple murders.

-- This report by The Canadian Press was first published May 20, 2022.