Justice Ian Nordheimer sentenced Clare Spiers to life in prison for the May 2004 slaying of Mimi Khonsari.
Earlier this year, he pleaded guilty to second-degree murder in the case.
The wife of a prominent local surgeon, Khonsari, 60, was babysitting her 11-month-old granddaughter when a man knocked on her door. Spiers broke into the house, strangled and stabbed Khonsari and dumped her body in a wooded area.
He drove Khonsari's car — with the baby inside — and abandoned it in a mall parking lot. The child was later found unharmed.
"Had it not been for the monstrous act of one person, my mother would be alive today," Khonsari's son, Navid, said in a victim-impact statement on Wednesday. "She would have met my wife and had the chance to embrace and kiss my two daughters."
The sentencing represents the end of decade-long push for justice in the case. In 2007, a jury convicted Spiers of first-degree murder in Khonsari's death. But the Ontario Court of Appeal tossed out the ruling after it found the Crown prosecutor had improperly vetted the jurors.
Spiers, who has a lengthy criminal record dating back to 1981, will be eligible for parole in December 2021.
However, Spiers won't automatically be granted parole when his eligibility date arrives, Nordheimer said.