In cross-examination, prosecutor John Cisorio heaped scorn on evidence by Christopher Husbands that he opened fire in a blind panic on two men he believed were out to kill him.
"A lot of these symptoms that you are chalking up to hypervigilance and paranoia are also consistent with your lifestyle choices," Cisorio said.
Husbands, 25, was adamant his fears were real.
He has pleaded not guilty to the planned killing of two men at the landmark Eaton Centre on June 2, 2012, in a shooting that also injured five people.
The Crown alleges Husbands gunned down Nixon Nirmalendran, 22, and a friend in deliberate retaliation for an almost fatal stabbing earlier that year.
"On June 2, you took the law into your own hands, didn't you?" Cisorio said.
"That's how you might interpret it but I felt my life was in danger," Husbands said on his third day on the witness stand. "I did not take the law into my own hands to go kill anyone."
Cisorio pointed out that Husbands was walking around with a fully loaded gun when he went to the Eaton Centre despite his professed paranoia and fear of crowds.
The mall visit was at his girlfriend's urging, Husbands said, and the friend's firearm made him feel safer because he knew Nirmalendran and the others who had attacked him carried guns.
"If you had the gun, you weren't going to throw it at them, were you?" Cisorio said.
"The gun is there to be used."
"It's there to protect myself."
Husbands, a drug dealer, maintains he suffered flashbacks, became paranoid, and developed a fear of crowds as a result of the attack in February 2012.
Cisorio suggested the accused brazenly went about his frequently illegal business in crowded places and his fears weren't real.
At the time of the mall shooting, Husbands was on bail for convictions related to obstruction and sexually assaulting the mother of his now six-year-old daughter. He breached them all.
"I didn't say I was going out to break my bail but it's something I ended up doing," he admitted.
"Nothing stops Mr. Husbands, right?" Cisorio said.
"I don't know how to answer that question."
Cisorio said Husbands lied to police after he turned himself in following the mall shooting in an effort to obscure a link between the February stabbing attack and the June shooting.
The witness said he was only trying to make clear he was not interested in talking to the officers, who quickly formed an opinion that the mall shooting was related to the stabbing.
"I wasn't going to change their mind," said Husbands, neatly dressed in jacket and tie.
He again said he had no idea what motivated the February assault but said it was not because he had slept with the mother of one of his attackers.
The trial continues Thursday.