Stuart O'Connell Criminal Law Blog

Subject:  Unexplored theory of liability--trial fairness--fundamentally unfair to convict an accused person on a theory of which they are entirely unaware. At the very least, a trial judge ought to  alert trial counsel to the possibility of a conviction on a theory of liability which the Crown has not explicitly advanced nor which can be fairly inferred as having being put in play from the argument and evidence presented by the Crown.  The trier of fact is not confined to the Crown’s theory in determining liability. As a general principle, a conviction may be based on an alternative theory of liability not advanced by the Crown so long as it falls within the wording of the indictment and is supported by the evidence.   However, the application of this principle is not without constraint. In particular, this principle does not address the corresponding principle of trial fairness . An accused person is entitled to know the case that they are being asked to meet. It is fundamentally un

From time-to-time, police officers will testify as experts on the basis of expertise that has been obtained through practical experience on the job over many years. The boundaries of any proposed expert opinion must be carefully delineated.   As well, t he trial judge must ensure that the expert stays within the bounds of their expertise and that the evidence is properly the subject of expert evidence.   The guilt or innocence of accused persons that the police officer had encountered in the past is generally not legally relevant to the accused’s guilt or innocence. [FN1] In R. v. J.T ., 2021 ONCA 922 (CanLII), the Appellant argued that unlawful pornography had been automatically downloaded onto his computer. The forensics police officer gave evidence that in his experience he had never seen child pornography end up on a computer in an automatic fashion. The judge relied on this evidence and ultimately convicted the accused.  The admission and reliance of the evidence was challeng