SAINT-JEROME, Que. -- The mother of two slain children had a sobering thought after their father was found guilty on Sunday of second-degree murder in their stabbing deaths nearly seven years ago.

"Tomorrow, I will not wake up with children," Isabelle Gaston said after a jury convicted Guy Turcotte at his second trial on first-degree murder charges in the slayings of Olivier, 5, and Anne-Sophie, 3.

Gaston expressed relief at the verdict, which came on the seventh day of the jurors' deliberations.

"Today, I hope the souls of Olivier and Anne-Sophie can be at peace," she said.

"For me, this is the day I can begin to rest. Since their deaths, I've had the impression my life has been a struggle. Now, it's all about healing."

Turcotte's lawyers were hoping the jury would find him not criminally responsible by way of mental disorder -- the verdict that was handed down in 2011 at his first trial.

The jurors had the choice of four possible verdicts: not criminally responsible or guilty of first-degree murder, second-degree murder or manslaughter.

A muffled "Yes" could be heard in the courtroom when the verdict was announced. It came from Gaston's direction.

Sentencing arguments will take place on Dec. 18.

A conviction on second-degree murder carries a sentence of life imprisonment but the court has some latitude on setting parole eligibility.

Quebec Superior Court Justice Andre Vincent asked the jurors if they had any recommendations for the minimum number of years Turcotte should serve -- the law states from 10 to 25 -- but they said they had none.

Pierre Poupart, Turcotte's lead lawyer, did not speak to reporters. It was not known whether he would appeal the verdict.

The Crown contended during the 12-week trial that Turcotte killed his children as an act of vengeance against Gaston because she was having an affair with one of his friends and because he could not handle the notion of being replaced by another man in their lives.

Defence lawyers said Turcotte was suicidal at the time and drank windshield washer fluid to kill himself. They argued that when he felt he was dying, he decided to take his children with him so they would not have to discover his body.

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.

The children were stabbed a total of 46 times and found in their beds with wounds to their upper bodies -- Olivier was attacked 27 times and Anne-Sophie another 19. Autopsy results showed the boy tried to defend himself from the attack.

The judge told the jurors that to find Turcotte not criminally responsible they had to believe he had proven he was incapable of judging the nature or quality of his acts or of knowing whether the acts were wrong.

Their deaths in February 2009 came less than a month after Turcotte's marriage to Gaston ended once the latter's infidelity had been exposed.

His criminal case -- and the verdict at that first trial -- infuriated many Quebecers and led to various protests.

The case was also among several across Canada to spur federal legislation, which became law in 2014 and was aimed at making it harder for those found not criminally responsible to gain their freedom.

The law gives the court new powers to create a new high-risk category that would hold mentally ill offenders longer and make it far more difficult for them to leave psychiatric facilities.

It also keeps victims' families in the loop about the status of such individuals and alert them when they are released.

Turcotte testified in his own defence, telling jurors he could only remember the night in snippets or "flashes."

He said he recalled attacking his son and hearing him whimper but couldn't stop himself from attacking either child.

Turcotte said he had been reading emails between Gaston and her new lover and made a decision he wanted to commit suicide.

The trial heard the couple had a rocky relationship spanning a decade.

Gaston told the trial that Turcotte warned her in a telephone conversation on the day the children were killed that if she wanted a war, she would get one.

She described their marriage as toxic but also noted that Turcotte was not a bad father.

"I never thought he could kill them," she repeated a number of times on the stand.

Witnesses who encountered Turcotte at the hospital following his arrest told jurors he asked not to receive treatment, with a nurse testifying he said he killed the children to spite his wife.

"He said he wanted to make her angry and that the way to do so was to take away from her what was most precious to her," Chantal Duhamel told the jury.

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.

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 it 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.

Poupart warned jurors from the outset that finding someone guilty for acts committed by someone not of sound mind would have legal consequences.

"Condemning a person who is not criminally responsible would shake the legal foundations and strike a blow to the integrity of the judicial system," he said.