Rules of Evidence: The Opinion Rule Flashcards
Section 23 of the Evidence Act:
statement of opinion is not admissable in a proceeding, except as provided by section 24 or 25.
Definition of “opinion”
“a statement of opinion that tends to prove or disprove a fact.
Rationale of the exlusionary rule for opinions?
To prevent the admission of unreliable, superfluous, or misleading evidence.
Three justifications for the exclusionary rule?
- where a witness offers a bare opinion it holds little probative weight
- there is a danger a witness offering opinion evidence will “usurp” the function of the tribunal of fact, by confusing inferences to be drawn from fact
- a witnesses evidence of opinion may be based on other evidence which may be inadmissable
Section 24: General admissability of opinions
A witness may state an opinion in evidence in a proceedings if that opinion is necessary to enable the witness to communicate, or the fact finder to understand, what the witness saw, heard, or otherwise perceived.
Section 25: Admissability of expert opinion evidence
Expert opinion evidence may consist of fact, opinion, or a mixture of the two.
Factual evidence of an expert is governed only by the general rules of s7 (admissability) and s8 (general exclusion)
In order to comply with s25, the expert opinion must:
- be that of an “expert”
- comprise “expert evidence”
- offer substantial help to the fact-finder in understanding other evidence or ascertaining any fact in the proceeding.
Definition of an “expert” as per s4?
“a person who has specialised knowledge or skill based on training, study or experience.
Judge determines if a person is properly qualified
Expert is required to demonstrate to the court that they have the requisite qualification to be deemed and “expert”
Definition of “substantial help”
substantial helpfulness seeks to offer a “more rational test that assesses the reliability and value of the expert opinion on its merits”
it “necessitates consideration of an amalgam of relevance, reliability, and probative value”.
Proven facts and provisional admissability under s14
section 14: provisional admission of evidence
s25(3) requires that the fact is or will be proved.
The expert witness may state the facts on which the opinion is based, or give the evidence on the basis that it will be proven.
Expert evidence about sanity (s 25(4)).
If the experts opinion about the sanity if a person is based on a statement that person made to the expert, then the statement of the person is admissable and neither the hearsay nor previous consistent statement rules apply.
Therefore excludes statements made by others.
The conduct of experts.
Experts must:
- state their qualificaitons
- state the facts, matters, and assumptions that opinions are expressed on
- state reasons for opinions given
- refer to any literature used or replied upon
- not give evidence outside their area of expertise
- state if their opinion might be incomplete or inaccurate
- assist the court impartially
- not advocate for any party.
Expert witness notice requirement
If the defendant intends to call an expert witness, he or she must disclose the brief of evidence or report at least 14 days before the date fixed for trial.
