A jury is now weighing the fate of a man accused of killing and dismembering his ex-girlfriend, then discarding her remains in several Toronto-area locations.
Chun Qi Jiang is charged with first-degree murder in the death of 41-year-old Guang Hua Liu, whose body parts were found in parks and waterways in August 2012.
Crown prosecutors allege Jiang killed Liu, with whom he had an on-again, off-again relationship, after she spurned him for a new boyfriend.
But the defence says it was Jiang's 66-year-old mother who fatally stabbed Liu and cut her into pieces.
Jiang's lawyers say he helped cover up the gruesome crime to protect his mother, who has since died.
Ontario Superior Court Justice Gisele Miller told the jury that in order to convict Jiang of first-degree murder, they must find he deliberately set out to kill her or cause her potentially fatal harm.
If they find he meant to kill her, but did not plan to do so, he must be found guilty of second-degree murder, Miller said.
If they find he killed her but did not mean to, the verdict must be manslaughter, she said.
Should jurors have reasonable doubt about whether Jiang killed Liu, they must acquit him, the judge said.