3. the Exclusive Rules of Evidence - The opinion rule Flashcards
Outline the opinion rule in S23 EA06?
23 Opinion rule
A statement of an opinion is not admissible in a proceeding, except as provided by section 24 or 25.
How does the EA06 define “opinion”?
The Act defines “opinion” as “a statement of opinion that tends to prove or disprove a fact” (s4). The distinction between what is fact and what is opinion is sometimes unclear
What is the rationale for the exclusionary rule?
Must Know
The rationale of the exclusionary rule is essentially to prevent the admission of unreliable, superfluous or misleading evidence. To admit such evidence would result in the admission of evidence of doubtful relevance and be a waste of court time.
What are the justifications for the exclusioinary rule?
The justifications for the rule include that:
* where a witness offers a bare opinion it holds little probative weight
* there is a danger that a witness offering opinion evidence will “usurp” the function of the tribunal of fact, which is to draw the necessary inferences from the facts presented in evidence. The opinion evidence could confuse the tribunal of fact and prolong proceedings.
* a witness’s evidence of opinion may be based on other evidence which, if stated expressly, would be inadmissible (for example, where an opinion is based largely on propensity evidence).
Outline general admissibility of opinions in S24 EA06?
24 General admissibility of opinions
A witness may state an opinion in evidence in a proceeding 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.
In order to be admissible under S24, the statement of opinion must fulfil two basic criteria. What are they?
- opinion must be the only way in which to effectively communicate the information to the finder of fact,
- the witness must be stating an opinion (be it conclusion, inference etc) from something personally perceived.
Outline admissibility of expert opinion evidence in S25 EA06?
25 Admissibility of expert opinion evidence
(1) An opinion by an expert that is part of expert evidence offered in a proceeding is admissible if the fact-finder is likely to obtain substantial help from the opinion in understanding other evidence in the proceeding or in ascertaining any fact that is of consequence to the determination of the proceeding.
(2) An opinion by an expert is not inadmissible simply because it is about—
(a) an ultimate issue to be determined in a proceeding; or
(b) a matter of common knowledge.
(3) If an opinion by an expert is based on a fact that is outside the general body of knowledge that makes up the expertise of the expert, the opinion may be relied on by the fact-finder only if that fact is or will be proved or judicially noticed in the proceeding.
(4) If expert evidence about the sanity of a person is based in whole or in part on a statement that the person made to the expert about the person’s state of mind, then—
(a) the statement of the person is admissible to establish the facts on which the expert’s opinion is based; and
(b) neither the hearsay rule nor the previous consistent statements rule applies to
evidence of the statement made by the person.
(5) Subsection (3) is subject to subsection (4).
What is S25 concerned with?
Must Know
Section 25 is concerned only with the admissibility of expert opinion evidence. Expert evidence may consist of fact, opinion, or a mixture of the two (s4). Factual evidence from an expert will be governed only by the general rules in ss7 and ss8, and any other admissibility rules applicable in the individual case.
Where evidence is opinion evidence, in order to comply with S25, what must be satisfied?
Must Know
the opinion must
* be that of an “expert”
* comprise “expert evidence”, and
* offer substantial help to the fact-finder in understanding other evidence or ascertaining any fact in the proceeding
What is an expert as defined in S4?
Section 4 of the Act defines an “expert” as “a person who has specialised knowledge or skill based on training, study or experience”. The judge must determine whether the expert witness is properly qualified to testify.
What does S25(1) provide?
Must Know
Section 25(1) provides that expert opinion evidence will be admissible if the fact-finder is likely to obtain substantial help from the opinion in:
* understanding other evidence, or
* in ascertaining any fact that is of consequence in the determination of the proceeding.
What does substantial help replace?
“Substantial help” replaces the two defining common law rules that related to expert opinion evidence and are abolished in s25(2): the common knowledge and ultimate issue rules. The common knowledge rule stated that an expert could not give an opinion on matters that were within the common knowledge of the jury. The ultimate issue rule provided that an expert could not give an opinion on the ultimate issue in the case.
What information is an expert allowed to base their opinion on?
Must Know
Where material, such as books and journal articles, contribute to the general body of information on any given topic, an expert witness is allowed to base his or her opinion partly on this information: to do otherwise would involve a costly and time-consuming parade of experts in court. (For example, research on memory processes has been conducted by a large number of scientists, the results of which make up a body of knowledge, but no one scientist has personally conducted a sufficient number of experiments to be able to give a full breadth of comment on the basis of personal experience alone.)
Can an expert base their opinions on the facts of supplied by others?
Must Know
An expert opinion may also be based on facts that are supplied by others, such as analyses of body tissues carried out by colleagues, or the research findings of other scientists. In this way, the facts on which an expert witness bases his or her opinion may be assumed facts, or facts of which they have no first-hand knowledge (for example, where there are marks on a body, a surgeon who has not seen the body may be asked whether, given the nature of the wounds, they could be self-inflicted). The expert should state the assumed facts on which the opinion is based, and the admissible evidence offered is the assumed facts themselves. If research findings were relayed directly to the court, rather than being used to support and explain the conclusions reached by the expert witness, they would be hearsay evidence and may be excluded under s18.
Expert witnesses should be impartial in their assistance to the court. In R v Hutton, the court of appeal approved principles similar to those for experts in civil cases and summarise much of the discussion of S25. What are they?
Must Know
- an expert must state his or her qualifications when giving evidence
- the facts, matters and assumptions on which opinions are expressed must be stated explicitly
- the reasons for opinions given must be stated explicitly
- any literature or other material used or relied on to support opinions must be referred to by the expert
- the expert must not give opinion evidence outside his or her area of expertise
- if an expert witness believes that his or her evidence might be incomplete or inaccurate without some qualification, that qualification must be stated
- an expert has an overriding duty to assist the Court impartially on relevant matters within the expert’s area of expertise, and
- an expert is not an advocate for any party.
