This case is about the Taylor test for fitness to stand trial and the separate test for not criminally responsible by reason of mental disorder.

Facts: after several years of deteriorating mental health, the appellant moved into a basement apartment with other tenants. Five days later, the appellant murdered one of the other tenants. The appellant told the police, surrendered himself, and explained how he carried out the murder.

In May 2016, a jury found the appellant unfit to stand trial and he was sent to an in-patient treatment facility to see if he could become fit. At a second hearing in August 2016, after spending over three months in hospital, a second jury reversed the first, finding the appellant fit to stand trial.

A jury convicted the appellant of murder. He appealed to the Court of Appeal for Ontario. The Court of Appeal dismissed the appeal. The Supreme Court of Canada granted leave to appeal on two issues. First, whether the Taylor test requires that the accused person can make rational decisions about the conduct of their defence. Second, whether the not criminally responsible defence applies when the accused person has the general capacity to know that society would regard their actions as morally wrong, but due to their mental disorder does not have the specific capacity to apply that knowledge to their actions.