A Barrie, Ont., mother has been found guilty of drowning her two young daughters, in a case an Ontario judge called "inordinately tragic."

Elaine Campione, 35, broke down in tears as she was declared guilty on two counts of first-degree murder Monday morning, sobbing uncontrollably for several minutes as the courtroom sat in silence.

Defence lawyer Mary Cremer did not dispute that Campione killed her daughters, three-year-old Serena and 19-month-old Sophia in October 2006, but argued that she was not criminally responsible for their deaths due to mental illness.

Cremer said her client was distraught with the outcome and maintained that her actions were caused by severe mental illness.

"This was a woman who was suffering, ravaged terribly by mental illness. Understandably she is devastated. She herself lost her children in this whole ordeal."

Crown prosecutors had argued that Campione drowned the girls ahead of a family court appearance, to prevent her abusive ex-husband from being granted custody.

Campione and her husband were going through an emotional divorce at the time of the girls' deaths. Leo, 35, had moved out of the family's home in Bradford, Ont.

The verdict comes with a minimum sentence of life in prison with no chance of parole for 25 years.

A few jurors could be seen wiping away tears as the verdict was read, prompting Justic Alfred Stong to order the Ministry of the Attorney General to provide any counselling the jurors may want to have.

"The circumstances of this case are undeniably and inordinately tragic," Stong said. "One can only hope that they do not reflect, even at their most extreme, a direction of our society."

Campione will receive her official sentence on Wednesday, after victim impact statements are read in court.

Cremer said they are already looking into grounds to appeal the decision.

"She was abused so badly by her husband that she suffered post-traumatic stress disorder," Cremer said.

The judge said the abuse was a significant factor in the murders.

"If Campione had not been so abused . . . so abused and discarded as a person, her daughters could still be alive," Stong said.

Over the course of her seven-week trial, jurors heard that Campione had been admitted to psychiatric wards and had attempted suicide.

The court also heard she had delusions that she was in danger of being killed, and that people were trying to steal her daughters. At times she behaved strangely, barring one of her girls from touching anything red, and maintaining that she saw aliens.

Earlier in the trial, Campione broke down in tears when photos of her dead daughters were presented to the court.

A police officer testified that the girls were laid out on their mother's bed holding hands, and wearing pyjamas and jewelry.

The court also heard that police discovered a videotape in the bedroom.

"There, are you happy?" Campione asks on the video, according to Crown prosecutor Enno Meijers. "God's taking care of them now."

Questions from the jury

On Friday, jurors asked the judge for an explanation of the phrase "morally wrong" in the midst of their deliberations. Justice Alfred Stong had used that term in the instructions he issued to jurors earlier this week.

Stong said that a defendant could be deemed not criminally responsible if he or she has a mental disorder that left them unable to discern that their conduct would be considered wrong in the eyes of ordinary people.

For example, Stong said, a mentally ill man committing an illegal act because he believes he is abiding by orders from God would not be considered "morally wrong."

If that person knew the act would be viewed as wrong in the eyes of society, however, then they would be held criminally responsible.

Jurors also asked the judge about the term "balance of probabilities." Stong said the defence had to prove that Campione is not criminally responsible on a balance of probabilities, which is a less stringent standard than "beyond a reasonable doubt."

Stong said that if jurors believed that Campione was more likely to be unaware that drowning her children was morally wrong due to her mental illness, they must issue a verdict of not criminally responsible.

With files from The Canadian Press