Carl Girouard was likely delirious and in psychosis when he attacked seven people with a sword in Quebec City on Halloween night 2020, psychiatrist Dr. Gilles Chamberland testified Friday morning.

The 26-year-old wasn't able to distinguish right from wrong when he was in that state, the doctor told a Quebec City court.

"When he's delirious, he's unable to realize [what he's doing]."

Girouard is facing two charges of first-degree murder and five of attempted murder, but the defence argues he can't be held criminally responsible for his actions because of a mental disorder.

Chamberland first met Girouard in April 2021 and saw him one more time in September of that year. His mandate was to understand the young man's mental state at the time of the attacks.

In a 29-page report he showed the jury, the psychiatrist analyzed Girouard's childhood behaviour and how his mindset evolved over time.

Early signs of trouble

Chamberland testified that Girouard showed signs of autistic and schizophrenic tendencies from a young age, such as having a fragmented way of thinking, not knowing how to communicate, and lacking social skills.

Girouard also showed aggressive and violent tendencies, according to the doctor.

For example, Girouard hit a doll with a stick during a session he did with a psychologist and his father and younger brother.

"In my opinion, already at the age of 12, there is already an embryo of what will happen," he told the jury. "It's almost a warning sign."

When Girouard became a teenager, he retreated into video games of war and combat and also started consuming cannabis.

That had a negative effect on his academic performance and social life, and he became increasingly antisocial and secluded, Chamberland said.

Chamberland said those were typical symptoms of someone who starts developing schizophrenia.

Spiraling into delirium

During Chamberland's meeting with Girouard, Girouard told the psychiatrist he wouldn't be able to understand him until he heard about his mission to kill people with a sword.

The defendant said he had gotten his first sword at the age of 16 and quickly took pleasure in cutting random objects with it outside in his backyard.

Chamberland testified that's when his client slowly started to become delirious.

Girouard began thinking it was normal and courageous to kill people with swords and imagined a character in his head, who would eventually become a sort of alter ego.

The psychotic symptoms worsened over time, reaching a peak once Girouard stopped working during the pandemic, Chamberland said.

Girouard wasn't able to distinguish between his imagination and reality when he was in that delirious mode, according to Chamberland.

For example, Girouard told Chamberland he yelled "run gang of sheep" after one of the attacks, a direct reference to one of his video games.

Chamberland refuted the idea that Girouard acted out of a desire to be noticed, saying his behaviour didn't match those of lone wolves who kill people for glory or attention.

For example, he had very specific and symbolic details in his plan and didn't research how to do a mass killing before.

Chamberland told the jury he also ruled out other elements that could push someone to act, such as being abused in one's childhood or feeling angry at society for one's own failures.

Psychologists reports from Girouard's youth show his mother was a loving and caring parent, but she had a lot of on her plate with three other sons to look after.

Girouard also did not express sadistic tendencies, Chamberland said.

The Crown, which maintains Girouard was sane and aware of his actions at the time of the attacks, will conduct a cross-interrogation of Chamberland on Monday.