The man accused of killing a retired tax judge, the judge's wife and their neighbour was "very strong" around the time of the deaths and talked about hurting people, the accused's former partner testified Monday.

"He was very, very strong, very strong," the woman told Crown prosecutor James Cavanagh during examination-in-chief Monday, adding that Ian Bush would talk about hurting people.

"He would just tell me how he could get someone to pass out. Well, putting his arm around their neck somehow. A lot of this stuff he'd talk and babble on about, I just wouldn't pay attention to," she said.

Raymonde Garon Alban Garon Marie-Claire Beniskos triple homicide June 2007 victims

From left, Raymonde Garon, her husband Alban Garon, and their friend and neighbour Marie-Claire Beniskos were found dead in the Garons' apartment building in June 2007. (Photo collage by CBC)

"He thought it was fascinating. He would talk about anything like that ... anything about how he could hurt someone, and it would take like nothing at all to do it."

The woman cannot be identified due to a court-ordered publication ban. She appeared in court Monday via video link from another room in the courthouse.

Bush is on trial for three counts of first-degree murder in the June 2007 deaths of retired Tax Court of Canada judge Alban Garon, 77, Garon's 73-year-old wife Raymonde, and their friend and neighbour Marie-Claire Beniskos, 78.

Bush, now 61, was charged in 2015 and has pleaded not guilty.

Also Monday, Bush's former partner pointed him out on some surveillance video shot at OC Transpo's Hurdman station, not far from the condo where the three victims were found dead.

She also identified a pair of New Balance 504 running shoes in a picture of Bush doing push-ups, and said they belonged to Bush. Court earlier heard prints from a pair of New Balance 504 running shoes were discovered at the crime scene in 2007.

The defence had no questions for the woman.

Son, daughter also testify

The Crown also called Brett Bush, the couple's youngest child, and Courtenay Bush, the eldest, to testify. Both identified their father in the OC Transpo surveillance video.

Brett Bush told court his father taught him how to defend himself by going for the nose, knees, then throat of an assailant. He also said his father hated the government and thought it was stupid. He did not recall hearing anything about taxes specifically.

And like his brother Brock Bush, who testified last week, Brett Bush told the defence during cross examination that his father showed him how to file his taxes.

Courtenay Bush told court that Ian Bush thought taxes were a form of stealing by the government.

"He doesn't like the government, to put it bluntly, in general," she said, adding that he had a "disdain" for bureaucracy.

Family under financial strain

Last week, Bush's ex partner and the son testified the family was under financial pressure around the time the homicides took place, and said that while Bush didn't want to talk about their problems, he had no issue talking about his hatred of taxes.

"Those rat bastards are not going to get any more money out of me," his ex-common law spouse recalled Bush saying.

"I would never bring [taxes] up because it always ended up in an argument.... He just didn't want the government to have any more of his money," she testified Thursday.

"He didn't agree with it at all. He'd always swear, he had a foul mouth. He was very angry. His voice would rise, and I used to say, 'Calm down, calm down, my God.'