Quebec's highest court has ordered a new trial for a Quebec man convicted in 2017 of stabbing to death a supermarket clerk.

The Court of Appeal ruled Monday that the trial judge's final instructions to jurors were confusing and complicated.

The appeal court overturned Randy Tshilumba's conviction and ordered a new trial.

Tshilumba was found guilty of first-degree murder in the 2016 killing of Clemence Beaulieu-Patry, 20, and sentenced to life in prison.

He had pleaded not guilty and testified he acted in self-defence because he believed Beaulieu-Patry wanted to kill him and other people in the store. His lawyer had argued that Tshilumba was suffering from a mental disorder.

The Court of Appeal says the trial judge erred by telling jurors that the defendant's behaviour after the killing was not relevant in determining guilt.

- This report by The Canadian Press was first published on Nov. 29, 2022