The more Dr. Edward Shen spoke with Rocky Rambo Wei Nam Kam, the more an understanding of the killer's behaviour began to dawn on the clinical psychologist.
He already knew the 29-year-old was obsessed with online video games and fantasy comics.
But then Kam described following Dianna Mah-Jones into her home — weapons in both hands — on the night of Sept. 26, 2017; he heard her panic as they came face to face.
"He said characters in the game don't scream," Shen testified Friday as he sat in a B.C. Supreme Court witness box at Kam's trial for the slayings of Mah-Jones, 64, and her 68-year-old husband.
Shen said Kam also talked about plunging a knife into Richard Jones more than 100 times.
"He couldn't explain why he stabbed him so many times. And he said because in games when you hit the person, it doesn't matter which part of the body you hit, that person dies," Shen explained.
"And if that person doesn't die you just keep hitting the button."
And that's how Shen arrived at a conclusion which now sits at the heart of Kam's contention he's not guilty of first-degree murder in the deaths of the South Vancouver couple.
"It was examples like these that convinced me that perhaps Mr. Kam was operating in what I call a gaming consciousness," Shen told the court.
"I think he would have been able to appreciate that there would be consequences, but I believe the consequences that he would have anticipated would be the ones that would be found in the game instead of reality."
'The line becomes blurred'
Justice Laura Gerow considered Shen's testimony Friday in a voire dire — a kind of trial within a trial — to determine whether the psychologist's theory of Kam's actions should be considered as evidence.
Kam has admitted to killing Mah-Jones and Jones in a brutal slaying. He has also admitted to buying gloves, twine and the pocket knife and hatchet in the weeks before the killings
But his lawyer has suggested that Kam may have thought he was inside a video game when he barged into the home and slaughtered the couple.
And that could make him guilty of manslaughter, not murder.
Shen claimed Kam's behaviour was a possible effect of Kam's decision to effectively isolate himself from the rest of the world through video games and comics.
"Indulging in such activities might loosen the conceptual boundaries of where reality begins and where reality ends," Shen said.
"The line becomes blurred."
'A big fan of Sylvester Stallone'
Wearing a grey turtleneck sweater, black pants and glasses, Shen calmly described meeting Kam for 11 hours of conversation at the North Fraser Pre-Trial Centre in Port Coquitlam.
The two spoke in Cantonese about Kam's troubled youth in Hong Kong and his irritation with his unusual name — a homage to two 80s action movie heroes played by one legendary actor.
"His father was a big fan of Sylvester Stallone," Shen said.
The middle of three children, Kam told Shen he had "negative feelings toward his mother, who he found "phony" and "manipulative."
They lived in the same house after moving from Hong Kong to Calgary but took great pains to avoid each other.
Kam moved to Vancouver the summer before the killings because he wanted to see the beach.
Shen said the games Kam told him he enjoyed playing involved ambushing, breaking in, spying and assassinating.
He said Kam spoke about the killings in much the same way as he testified in his own defence: "like he was a spectator on his own behaviour."
"That goes to show that he was probably in a different kind of consciousness while he was performing the act, versus while he was looking at the acts that he performed," Shen said.
Feigning or exaggerating symptoms?
The psychologist took great pains to explain "levels" of consciousness by removing his watch and holding it by the strap as he faced the public gallery.
People whose consciousness is geared toward money might ask how much it cost, Shen said. Others might ask where he bought it. Others might ask how long he's had it.
He suggested that Kam is able to slide in and out of a gaming consciousness without an obvious trigger.
"There's a possibility ... that he was applying the consciousness of gaming on reality without being aware of what he was doing," Shen said.
But the Crown challenged Shen's credentials and his theory, pointing out that he has almost no training in forensic psychology — which is the diagnosis or treatment of individuals in the context of criminal or legal matters.
Crown prosecutor Daniel Mulligan asked Shen whether gaming consciousness is a recognized condition. It's not.
He also asked whether Kam is the first subject Shen has met with the condition. He is.
"I have friends and know of people who enjoy playing games and spend a lot of time with them," Shen replied.
The prosecutor also suggested that Shen relied largely on Kam's own statements to reach his conclusions and would have been largely unable to assess whether the killer might have been malingering — exaggerating or feigning illness for personal gain.
The Crown has already accused Kam of acting in the courtroom.
The trial is expected to conclude next week.