A Quebec man found guilty of killing his two young children and sentenced to life in prison is appealing his sentence.

In 2015, Guy Turcotte was found guilty of second-degree murder in the stabbing deaths of his two young children Anne-Sophie, 3, and Olivier, 5, in February 2009. He was sentenced to life in prison with no parole eligibility for 17 years.

The former cardiologist was originally found not criminally responsible during his first trial in 2012, but an appeals court overturned the ruling and Turcotte was forced to stand trial again.

On Tuesday, Turcotte’s lawyer Pierre Poupart argued in front of the Quebec Court of Appeal for a reduction in his client’s sentence. Poupart told the court that the judge in Turcotte’s second trial failed to consider his client’s mental health as a mitigating factor during the sentencing.

“We’re not talking about a psychopath, but a loving father,” Poupart said.

He also said the sentencing judge described the killings as “cold-blooded murders,” which Poupart says wasn’t supported by the facts during the trial.

The lawyer said Turcotte has undergone psychiatric treatment since his arrest nine years ago and that it was determined that he no longer poses a threat to society.

The average sentence for second-degree murder conviction is 10 to 15 years, according to Poupart. He asked the panel of three judges to shave a few years off of Turcotte’s sentence.

Prosecutor Rene Verret, however, argued that Turcotte’s 17 years without parole should be upheld because there were many aggravating factors in the case, including the fact that Turcotte stabbed his children a total of 46 times and then tried to kill himself by drinking windshield washer fluid.

“He knew what he was doing,” Verret told reporters outside the courtroom. “A father who takes his children’s lives commits one of the most serious crimes.”

The Quebec Court of Appeal doesn’t hear from witnesses and Turcotte himself was absent from Tuesday’s proceedings. However, Isabelle Gaston, the mother of the murdered children and Turcotte’s ex-wife, attended. She told reporters that she wanted to be there for her children.

“As a parent, you are a parent one day and you’re a parent all your life. So even if my children are not physically here, I will honour their memory and be there for them, be their voice,” she said.

Gaston said the lengthy case has taken its toll on her.

“I'm still fighting with the image[s] in my head, with psychologists and psychiatrists, because that's the main battle for me, is to try to get out of my head those terrible images,” she explained.

The court is expected to rule on the appeal in the coming months.

With a report from CTV Montreal’s Stephane Giroux