Guy Turcotte has been found guilty of second-degree murder in the deaths of his two children.

Turcotte was being tried for first-degree murder for a second time in connection with the stabbing deaths of his children Olivier, 5, and Anne-Sophie, 3, on Feb. 20, 2009.

The 11-person jury reached the unanimous verdict on the seventh day of deliberations.

A conviction on second-degree murder carries a sentence of life imprisonment but the accused can be freed after a certain number of years.

Judge André Vincent asked the jury if it had a recommendation in terms of sentencing, but the jury replied after a brief deliberation that it did not have one to offer.

The prosecution and defence will present their recommendations for sentencing on Dec. 18.

Guy Turcotte has been found guilty of second-degree murder in the deaths of his two children. His ex-wife Isabelle Gaston reacts. 0:33

Mother reacts

Isabelle Gaston, the children's mother and Turcotte's ex-wife, said she was "happy" and "relieved" by the verdict, but that it was hard to consider it a victory.

"I will not wake up tomorrow with children," Gaston told reporters.

"I'm relieved for Olivier and Anne-Sophie, this is justice for them — a little girl of three and a little boy of five," she said, her voice breaking.

"I hope that Olivier and Anne-Sophie, their souls, will be able to rest."

Gaston said the verdict will help her to move forward with her life and start to heal.

"Since their deaths, my life has been a struggle, really a struggle," she said.

Turcotte admitted to causing the deaths of his children, but the defence argued the former cardiologist was not criminally responsible due to mental illness. ​

In the first trial in 2011, Turcotte was found not criminally responsible for their deaths.

Crown prosecutors successfully appealed the original verdict in November 2013 and the country's highest court announced early the following year it wouldn't hear Turcotte's appeal of that decision.

In the second trial, which began in September, Turcotte testified he drank windshield washer fluid on the night of the killings in an attempt to end his own life and, upon seeing death approaching, he stabbed his two children to spare them from waking up to a dead father.

The Crown, however, argued the killings were premeditated as revenge against Gaston, who had left him a short time earlier for another man.

Reliving the trauma

Gaston said living through a second trial was difficult and forced her to once again confront images that she had worked hard to put out of her head.

"At first, I didn't want to come back and testify, but then I chose to have hope in the prosecutors," she said.

"When you are a mother, or a father, you have to go over your own needs and fight for your children, for their rights."

4 possible verdicts

The Crown completed its final arguments last Wednesday, saying Turcotte had decided to commit suicide and wanted to kill his children to ensure they weren't raised by another man.

Earlier, in the final arguments for the defence, Turcotte's lawyer had argued his client was a loving father who would not have killed his children unless he was suffering from mental illness.

The jury had four possible verdicts from which to choose:

Guilty of first-degree murder.

Not criminally responsible due to mental illness.

Not guilty of first-degree murder but guilty of involuntary manslaughter.

Not guilty of first-degree murder but guilty of second-degree murder.

Judge Vincent told the jurors that to find Turcotte non-criminally responsible they had to believe that he had proven he was incapable of judging the nature or quality of his acts or of knowing whether the acts were wrong.

Duelling expert witnesses

The trial came down to duelling expert witnesses.

Experts on both sides agreed that Turcotte was suffering from mental issues — an adjustment disorder with symptoms of anxiety and depression.

They differed on his state of mind, however, with defence experts saying Turcotte was obsessed with suicide, mentally ill and incapable of telling right from wrong.

Prosecution experts countered that he was in control and responsible for the acts.

Pierre Bleau, a Crown witness, said someone suffering from an adjustment disorder doesn't lose contact with reality, the ability to reflect or a sense of responsibility for his actions.

Defence witness Dominique Bourget, a forensic psychiatrist with a specialty in domestic homicides, testified Turcotte was suffering from "a major mental illness" that prevented him from developing an intent to kill.

Another psychiatrist, Louis Morissette, testified Turcotte killed his kids to prevent them from witnessing his eventual suicide and said that logic was faulty and the result of a sick mind.

Methanol a marginal factor, expert said

Morissette said the actions were the product of his troubled mental state and his suicidal thoughts and that Turcotte's consumption of methanol was a marginal factor.

The Crown and defence disagreed on when the accused consumed the windshield washer fluid and the impact it had on his actions.

Defence experts, as well as Turcotte, said he drank the fluid before the slayings in an attempt to commit suicide and then decided to kill his children to spare them finding his body the next day.

The Crown agreed that Turcotte wanted to commit suicide, but said he killed the children before consuming the liquid — perhaps an hour before his arrest, according to one expert.

Jurors heard it was impossible to know with certainty when and how much methanol was ingested.

Mother calls for expert accountability

After the verdict was announced, Gaston, a family doctor, said Quebec's medical college has "work to do" to ensure medical experts are made more accountable for their testimonies in court.

"When someone takes the stand in court and testifies that an adjustment disorder can justify the murder of children, I have serious questions," she said.

"It's still medicine, even if it's in a court, and we can't let that go without inspection and without analysis. If not, it undermines the public's confidence in its institutions."