#4762 - Opinion Evidence - BPC Criminal Evidence

OPINION EVIDENCE The "Ultimate Issue" Rule: Witness should not be asked questions or offer answers which require the Witness to venture an opinion on a fact-in-issue Exceptions Where the Court lacks the Witness's competence to form an opinion on a particular issue through: * lack of necessary direct knowledge, or * lack of necessary expertise Witnesses of Fact Stating their Opinion When the "opinion" is actually a statement of several facts - admissible as long as there is a proper appraisal of the facts. * Eg. "Defendant was drunk" - facts which Witness saw/heard/smelled which led to this opinion. Expert Opinion Evidence Where issue Court is required to determine is far removed from the court's expertise - needs opinion of expert to help determine. Expert opinion is admissible, but non-expert opinion should not be admitted. Party calling expert should ensure his evidence is limited to matters within his expertise on relevant and admissible issues. Is Expert Opinion Required? Difficulty distinguishing when the Jury should determine the issue and when an expert opinion is required (Jury likely to accept) Rule: Generally expert not required where offers opinion on normal human behaviour "normal human behaviour" - expert may be called when Defendant suffering from recognised medical condition or personality disorder. "Expert" Where a case requires expert opinion - only a suitably-qualified expert can give it. "Expert" - not necessarily require formal qualifications - requires specialised knowledge, information and study. Bias Party who wishes to call an expert should disclose to the court and other parties any interest the expert has or may seem to have.