TORONTO -- A Toronto police officer on trial for gunning down a teen on an empty streetcar denied firing at the knife-toting youth merely on a hunch he might attack.

Const. James Forcillo, who is charged in the death of 18-year-old Sammy Yatim, disagreed with a suggestion from a Crown prosecutor Friday that he shot the teen without reasonable grounds.

"Reasonable grounds is more than a hunch or a suspicion, it's more than a feeling," Crown lawyer Milan Rupic said as he cross-examined Forcillo.

"The shooting of Mr. Yatim is in the category of maybe he's going to attack. Until Sammy Yatim started to run down the street at you, you did not know what he was going to do."

"I wholeheartedly disagree," Forcillo said.

Forcillo has pleaded not guilty to second-degree murder and attempted murder in Yatim's death.

The jury has heard that on a night in July 2013, Yatim had consumed the drug ecstasy before boarding a streetcar where he pulled out a small knife.

Videos and audio played at the trial have shown that Forcillo arrives on the scene, yells repeatedly at Yatim to "drop the knife" and fires nine bullets at the teen after a 50-second confrontation.

Forcillo has testified that he believed Yatim was about to attack him, which is why, in accordance with police training, he fired his gun.

During a tense cross-examination, Rupic suggested, however, that Forcillo was not thinking the way a police officer should.

"In your mind, officers are entitled to bark orders and make demands and expect people to follow, and you were amazed when someone didn't follow," the Crown lawyer said.

"Police officers are entitled to choose what they think will work best in a particular situation," Forcillo contended.

"Your job is not to win but to resolve the situation with the least amount of force necessary," Rupic later went on.

"My job is to get the situation resolved," Forcillo said firmly. "But one way or the other, Mr. Rupic, I'm going home that night."

Rupic also said that Forcillo intended to kill Yatim when he fired nine times.

"Are you suggesting that firing nine bullets at somebody is not likely to kill him?" Rupic asked.

"I fired the bullets at him because I thought he was a threat to my life," Forcillo said.

"I'm asking if you knew you were likely to kill Sammy Yatim," Rupic asked.

"I am not considering whether these bullets are going to kill him. I'm considering whether or not they're going to stop him."

The jury has heard that the moment Forcillo believed Yatim was about to attack was when the officer saw the teen jerk his knife towards him.

Forcillo has mimed the movement for the court --standing up in the witness box, stretching out his right arm and flicking his wrist at the jury -- and has said it made him realize an attack was imminent.

The jury has heard that Forcillo issued a warning to Yatim not to take another step towards police and fired when the teen moved forward.

Rupic suggested Forcillo could have tried other non-lethal use-of-force options before shooting.

"This is not a case where you tried, not even once, to establish a connection through communication, to try to calm a person down," Rupic said.

"I used lawful techniques taught in Toronto police training to try and resolve the situation," Forcillo maintained. "The time and the place for that is not being ten feet away from a person with a knife."

Crown prosecutors argue Forcillo's actions during the incident weren't necessary or reasonable. Forcillo's lawyer contends his client's actions were justified and carried out in self-defence.