The mother of two slain children was cross-examined on Tuesday in a St. Jerome courthouse, where she said in hindsight she now considers herself a victim of psychological abuse.

Isabelle Gaston was questioned about how her relationship with her then-husband, Guy Turcotte, deteriorated in the months leading up to the deaths of their children Olivier and Anne-Sophie.

Gaston called the dynamics of her relationship with Guy Turcotte toxic; adding that she felt he always criticized her and told her she was never happy.

Turcotte is on trial for the second time, charged with the first-degree murders of his children.

The defence lawyer questioned Gaston about the final vacation the four took together, and Gaston said it was polite, with her and Turcotte mostly staying alone and doing their own thing.

At this point she was cheating on her husband with her personal trainer, but Turcotte was unaware.

Gaston said that the months and years leading up to that vacation had become increasingly difficult, but that Turcotte was never verbally or physically aggressive.

However she did state she now sees herself as a victim of verbal abuse. Gaston said that after the murders she took a class to find out why she kept returning to Turcotte in their stormy relationship. 

Gaston also confirmed her statement that Turcotte was an involved parent and a good father, who participated in activities such as bathing his children and preparing dinner.

However Gaston and Turcotte had lived apart at least twice, and were separated once again when their children were killed.

The defence also brought up their last phone conversation Gaston had with Turcotte on the day of the killings. She had told him she changed the locks and he was upset. She said he told her, “You want a war, you'll get a war.”

The defence asked her how she interpreted that expression, and she said she was worried he was going to do something to her, but never to their children.

At times during the cross examination the judge reminded the defence that the couple wasn't on trial.

Turcotte admitted last week that he killed Olivier, 5, and Anne-Sophie, 3. The defence has yet to reveal its strategy.