SAINT-JEROME, Que. -- The ex-wife of a Quebecer convicted of murdering their two children told him to look her in the eye Friday as she defiantly declared that while he has broken her heart, he has not broken her resolve.

"I want you to know, Guy Turcotte, that you have achieved your goal," Isabelle Gaston said at his sentencing arguments as he sat shaking in the prisoner's box, his head low.

"I want you to look me in the eye...You have broken my heart forever, but I want you to know you have not broken my resilience," she added, as many in the courtroom cried.

The handcuffed Turcotte, who was found guilty earlier this month of second-degree murder in the 2009 stabbing deaths of Olivier, 5, and Anne-Sophie, 3, cried and tried to wipe away the tears as he listened to her.

The judge hearing the arguments invited Turcotte, 43, to speak and the ex-cardiologist jumped at the opportunity.

"People cannot understand the shame I have," he said in a weak-sounding voice. "I cannot look people in the face, I'm so ashamed."

Turcotte, 43, said he stood trial as a way to explain his actions.

"I want to tell you Isabelle, I didn't go to trial to make you feel responsible," he said, adding he wanted to explain what he'd done and gone through "after hitting the bottom of the barrel."

"It was not to hurt you. I know I can never forgive myself what happened."

The Crown suggested Turcotte serve a minimum 20 years before he's eligible to apply for parole, while the defence countered it should be less than 15 and closer to 10.

Quebec Superior Court Justice Andre Vincent will rule on Jan. 15.

Gaston, the only witness the Crown chose to have testify Friday, told the judge she always wanted to be a mother but that losing her children ended that dream.

"The woman who existed in 2009 no longer exists and never will again," Gaston said, explaining she has tried to have other children since the slayings and underwent procedures to help that happen.

"But at 43, I have lost hope," she said, choking back tears.

The defence didn't call any witnesses but filed updated psychiatric and psychological assessments.

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

The minimum time to be served before being able to apply for parole is 10 years, while the maximum is 25 years.

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.

Vincent asked them last week if they had any recommendations for the minimum number of years Turcotte should serve but they said they had none.