The man who killed 10 pedestrians and wounded 16 others in the Toronto van attack in 2018 should be found not criminally responsible for his actions, his lawyer argues, because he “lacks capacity to rationally weigh the moral consequences of his actions” due to his autism spectrum disorder diagnosis.

During his closing arguments at the trial for 28-year-old Alek Minassian, who has been charged with 10 counts of first-degree murder and 16 counts of attempted murder, defence lawyer Boris Bytensky argued that simply because his client told psychiatrists that he knew it was morally wrong to kill doesn’t mean it was a concept he truly understood.

"Just because he uses certain magic words... doesn't mean he understands them at all,” Bytensky said.

Minassian has already admitted to driving a rented cargo van on sidewalks along a busy stretch of Yonge Street in North York on the afternoon of April 23, 2018, deliberately striking pedestrians in his path.

The focus of the trial has been whether Minassian meets the threshold set out under Sec. 16, which states that a person is NCR if they were suffering from a mental disorder that rendered them “incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong.”

Bytensky told the court Thursday that his client’s diagnosis manifested itself in a way that created “a perfect storm” to “severely” distort Minassian’s way of thinking.

Over the course of the six-week trial, several psychiatrists testified on behalf of both the Crown and defence to offer insight into Minassian’s diagnosis and his frame of mind before, during, and after the attack.

Dr. Alexander Westphal, a U.S. psychiatrist who served as the key witness for the defence, suggested that Minassian did not understand the moral wrongfulness of his actions.

Two of the concepts explored by Westphal and other defence psychiatrists were the concepts of “over-valued ideas” and “hyper-focus.”

The psychiatrists testified that Minassian became hyper-focused on mass killings, the manifesto of Elliot Rodger, and the idea that he could gain notoriety by becoming a mass murderer himself.

He said Minassian’s goal was not to intentionally harm people as much as it was to move up the “leaderboard” and have the highest kill count.

It was his desire for notoriety that motivated the deadly attack, not anger or rage, Bytensky said.

Minassian’s lack of empathy, Bytensky said, also left him unable to comprehend the “the real horrific impact” that his actions would have on other people.

He said at no point did Minassian express remorse or regret or have an emotional connection with his victims.

One defence expert testified that Minassian had only a “superficial” understanding of the emotional world of others, including the impact the attack would have on his parents.

When describing his own emotions, the psychiatrist said, Minassian’s answers focused on physical symptoms, including feeling hot when angry.

Bytensky noted that Minassian’s empathy deficit, however, was different from that of psychopaths or those with anti-social personality disorder.

He said testimony at trial indicated that psychopaths have the capacity to understand the emotions of others while those with ASD generally do not.

He said that for that reason, he does not believe finding Minassian NCR would “open the flood gates” for others with emotional deficits to launch similar defences.

Bytensky said Minassian’s ASD caused him to have “rigid or concrete” thinking that impaired his moral reasoning.

One example of this, Bytensky said, was Minassian’s belief that his only options for the future were carrying out the van attack or failing at his new job, which he was set to begin shortly after the attack.

Another example, Bytensky said, was that Minassian said if he carried out another attack, he would stick to the same narrative to be “consistent” with what he wrote on Facebook and told police.

Minassian’s lawyer also took issue with expert testimony by psychiatrists for the Crown, who suggested Minassian did struggle morally with his decision at times.

Bytensky said the fact that Minassian was nervous in the moments leading up to the attack wasn’t evidence of a “moral struggle,” as was suggested by a Crown expert, but was evidence that he was nervous about whether he was actually going to follow through with his plans.

Bytensky also claimed that the two psychiatrists called by the Crown lacked experience in assessing persons with ASD, noting that the key defence psychiatrist had qualifications that were “head and shoulders” above the qualifications of anyone else who testified at trial.

“The fact that the Crown… chose not to bring in or consult a single expert knowledgeable in autism... is shocking," Bytensky told the court Thursday. "If I were a member of the public, I would be outraged by that.”

The defence lawyer added that Crown expert Dr. Scott Woodside didn’t do any tests “to determine the severity of Minassian’s diagnosis,” which led the psychiatrist to assess Minassian through a “faulty lens.”

During his assessment of Minassian, Woodside said the accused told him he knew the public would view his actions as “despicable.”

Woodside added that becoming infamous was part of Minassian’s “calculation,” implying that he had a clear knowledge that what he was doing was morally wrong.

Multiple psychiatrists testified that Minassian was not suffering from any psychosis or delusions at the time of the attack and court has previously heard that in about 80 to 90 per cent of cases where there is a finding of NCR, psychosis is the condition under consideration.

Bytensky said although Minassian doesn’t suffer from psychosis, the impact his diagnosis had on his ability to make a rational choice was “effectively the same.”

He noted that nowhere in Sec. 16 does it say that an accused must experience psychosis to meet the threshold to be found not criminally responsible.

“The fact that those are typically the diagnoses, it is factually true but legally unnecessarily and unhelpful,” he said.

“(Mr. Minassian) does not have the ability to take full stock of the key factors in order to rationally choose whether or not to do the act.”

The Crown is expected to make closing submissions when the trial resumes at 9:30 a.m. on Friday.