Now Guy Turcotte is waiting to learn whether three judges will agree with the Crown that he should face a new trial in the 2009 stabbing deaths of his son Olivier and daughter Anne-Sophie.
The Quebec Court of Appeal judges will rule eventually on whether the high-profile case should return to court for a new trial.
Turcotte was not present at the courthouse as the Crown outlined the reasons why the not-criminally-responsible verdict should be annulled and a new trial ordered in a criminal case that has prompted public outrage.
During his highly publicized murder trial, Guy Turcotte admitted to repeatedly stabbing his kids, but he denied criminal intent.
The children were stabbed 46 times by Turcotte in what he described as a blackout-filled night. He testified that he only remembered the evening in flashes.
The trial heard from numerous witnesses, including Turcotte himself. Medical experts for the defence testified he was suffering from the mental effects of the breakup of his marriage to Isabelle Gaston, who had left him weeks earlier for her personal trainer, a friend of the couple.
The not-criminally-responsible verdict was one of four the jury weighed. It meant Turcotte was unable to know, at the time, that he was doing something wrong.
It's a verdict that should not have been on the table, the Crown contends. Michel Pennou, who did not work the original case but argued the appeal on Monday, said the judge failed to properly instruct the jury.
Turcotte drank washer fluid later that evening in 2009 in what he says was an attempt to kill himself. Pennou said a not-criminally-responsible verdict should be reserved for cases of mental illness, not ones where a suicide attempt might have triggered an after-the-fact blackout.
Under questioning from the chief justice of the appeal court, Nicole Duval Hesler, about why the Crown didn't raise some of its points during the trial, Pennou conceded it was a mistake.
Pennou told the judges that just because the Crown made an oversight didn't mean the judges should repeat it. He said the judge also erred in leaving the not-criminally-responsible verdict available as a possible option for the jury.
The defence has denied those arguments, contending that the Crown had plenty of time to raise objections before the jury went into deliberations.
Lawyer Pierre Poupart said both sides agreed to the parameters of the trial and the Crown knew what was at stake when the not-criminally-responsible defence was introduced during what he called a "long, arduous, demanding" trial.
He said the jury came to a reasonable verdict and it was important the appeals court not be used as an unofficial 13th juror.
The case helped spur new federal legislation aimed at making it harder for those found not criminally responsible to gain their freedom.
Turcotte was eventually deemed fit for release from a mental institution, where he'd stayed following the verdict, after only 46 months in custody since the slayings.
The Crown wants a new trial on the original charges: two counts of first-degree murder.
The defence says the court should reject the appeal, but that any new trial should be on the much-reduced charge of manslaughter.
Turcotte's ex-wife, Isabelle Gaston, sat in the front row with her mother Monday, listening to the Crown and scribbling notes.
She told reporters she's had months to immerse herself in the arguments and jurisprudence, as part of what has become a personal mission for the emergency-room physician.
"It made me feel hope that this injustice will finally be corrected so it's a step forward for me," Gaston said of the Crown's attempt for a new trial.
She made clear that she won't accept anything less than the first-degree murder charges Turcotte initially faced.
"I'm confident," Gaston said.
"But I'll always be afraid, I think, because this process has not gone as expected from the beginning."