When they are making the decision whether or not the person is criminally responsible, they would likely consider medical evidence about the person's mental disorder. They first have to establish that the person suffers from a major mental disorder. Then they have to determine whether that mental disorder renders the person incapable of understanding the moral wrongfulness of their act or the nature and quality of the act.
Once that decision has been made, they are found NCR, and that's when we get into the regime we're discussing today, which is the review board regime.