9. Admissibility of Evidence - Opinion
9.1 Lay opinion
- Opinion Evidence Is Excluded Unless Specifically Excepted
Definition
An opinion is any inference from observed facts or other communicable data: R v Perry (No 4) (1982); Allstate Life Ins Co v ANZ (1996)
The rule operates in relation to both hearsay evidence of an opinion as well as in court evidence in the form of an opinion.
The problem is there isn't a distinct line between fact and opinion, they exist on a continuum.
The opinion rule
s76
(1) Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed.
(2) Subsection (1) does not apply to evidence of an opinion contained in a certificate or other document given or made under regulations made under an Act other than this Act to the extent to which the regulations provide that the certificate or other document has evidentiary effect.
• Note: Specific exceptions to the opinion rule are as follows:
* summaries of voluminous or complex documents (subsection 50(3));
* evidence relevant otherwise than as opinion evidence (section 77);
* lay opinion (section 78);
* expert opinion (section 79);
* admissions (section 81);
* exceptions to the rule excluding evidence of judgments and convictions (subsection 92(3));
* character of and expert opinion about accused persons (sections 110 and 111).
Other provisions of this Act, or of other laws, may operate as further exceptions.
Smith v The Queen (2001) (Difference between fact and opinion in relation to identification.)
Facts: Smith was accused of robbery identification of Smith was made in court by 2 police officers who had worked on the case and dealt with Smith before, from stills taken from security videos. The police did not see the robbery.
Held: The majority said this evidence wasn't relevant because the jury can look at the photo and decide for themselves.
• Kirby J dissented and said it was relevant because the police officers were better placed to identify Smith - he then discussed opinion evidence.
• For the purposes of s76, the distinction between evidence of a fact and an opinion is one of degree rather than kind - the Police’s evidence was opinion as it was identification evidence and therefore s76 applied and the evidence was inadmissible.
• S78(a) was not satisfied as the matter or event in question was the robbery and the police had not seen the robbery.
• If the police officers had known Smith better than the jury then their evidence would be closer to fact than opinion.
Exception: evidence relevant otherwise than as opinion evidence
s77
The opinion rule does not apply to evidence of an opinion that is admitted because it is relevant for a purpose other than proof of the existence of a fact about the existence of which the opinion was expressed.
• This is similar to the provision allowing hearsay evidence for a non-hearsay purpose. Like s60, if evidence is admissible for a purpose other than opinion, the opinion rule doesn't apply which means it is admissible towards the fact which the opinion was about. But remember it only means the opinion rule doesn't apply, the Court could still use discretionary exclusions, warning or s136 to limit its use.
Exception: lay opinions
s78
The opinion rule does not apply to evidence of an opinion expressed by a person if:
(a) the opinion is based on what the person saw, heard or otherwise perceived about a matter or event; and
(b) evidence of the opinion is necessary to obtain an adequate account or understanding of the person's perception of the matter or event.
- Kinds of Opinion Evidence:
• Age of a person, drunkenness etc.
• Identity
• Speed, Weather, State of the road or floor
• Emotional state: R v Harvey (1996)“a look like sexual gratification –that’s the best way that I can express it.”
9.2 Expert opinion
Exception: opinions based on specialised knowledge
s79
If
a person has specialised knowledge based on the person's training,
study or experience, the opinion rule does not apply to evidence of an
opinion of that person that is wholly or substantially based on the
knowledge.
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Continued
Expert Opinion Exception: s.79 – Requirements
- An Expert’s Evidence Must First Be Reliable
(1.) The witness must have “specialised knowledge”
–Undefined in Act, so look to the common law
–Three approaches are to be considered
Approach
1: Does the Field of expertise have “general acceptance” (recognition)
in the relevant scientific discipline - (Court looks to the scientific
community (journals etc) to see if they accept it. If they do then the
court will accept it as “specialised knowledge”)
Approach 2: Is
evidence from that field of expertise reliable - (Deburt test – Court
itself assesses the reliability of the matter and determines whether it
is “specialized knowledge”
Approach 3: Hybrid –Recognition is relevant to question of reliability
(2.) Knowledge must be based on witness’s training, study or experience
• Both conceptual and experiential training can be taken into account
• Ad hoc experts can also testify (eg. repeated listening to a tape)
(3.) Opinion must be “wholly or substantially” based on that knowledge
• The expert must stay within his/her area of expertise
•
The testimony must be in admissible form so as to distinguish the
assumed facts, to see if they agree with evidence and the reasoning
process, to see that expertise is what is being applied and not just
common speculation Assumptions: If you put facts as mere assumptions to
the witness, s.60 does not make them admissible as evidence of the fact
assumed
- An Expert’s Testimony Must Differentiate Between Facts and Reasoning
•
This makes it possible to answer the question whether it is based on
specialised knowledge and to see what is being used is not speculation.
HG v R (1999)
Facts:
appellant (HG) convicted of two offences of having sexual intercourse
with a child under 10 child was the daughter of his de facto wife
•
Victim lived with natural father and later with her step father HG.
Victim made allegations after the event. Victim was referred by a GP to
a psychologist, Mr McCromby, who over time, also received info from
various other sources including the victim, and came to the conclusion
that she had been sexually assaulted in her past by her natural father
(not HG). She had effectively blanked out the events involving her
natural father, and when certain things happened later in her life, she
late developed the idea that HG assaulted her.
• The qualified
psychologist (McCromby) was called, and gave evidence that the child
had actually been abused by her real father when she was much younger.
• Mr HG wanted to call evidence from McCromby. There was no question about his expertise as a psychologist generally.
Issue: Was this opinion based on the expert’s specialised knowledge?
Held: Gaudron J: opinion must be reliable. The ultimate test is reliability.
•
Gleeson CJ: The psychologist’s opinion was based on a combination of
speculation, inference, personal and second-hand views as to the
credibility of the complainant, and a process of reasoning which went
well beyond the field of expertise of a psychologist therefore it was
not admissible.
• It is important that the opinions of expert
witnesses be confined, in accordance with s79, to opinions which are
wholly or substantially based on their specialised knowledge experts
who venture opinion outside their field of specialised knowledge may
invest those opinions with a spurious appearance of authority, and
legitimate processes of fact-finding may be subverted.
- The Expert Must Stay Within his/her Area of Expertise
• It is OK to partly use common knowledge
• It is not OK to use non-expert reasoning: HG v R
•
If the court cannot be sure of this, the evidence is strictly speaking
not admissible, and, so far as it is admissible, is of diminished
weight: Makita (Australia) Pty Ltd v Sprowles (2001) NSWCA
Expert Opinion Exception: s.79 – The Basis Rule
- It Is Not Necessary That Evidence Of The Underlying Facts Is Admissible & Relevant
• At common law, if facts are representations (eg what a patient complained of to the doctor), then:
(a)
If they are not disputed or are admissible, they can be used for
non-hearsay purpose (s.60) if first-Hand hearsay (Lee v R (1998) HCA)
(b) If they are disputed or unreliable, either:
s.135 can be used to exclude the evidence
s.136 Order can be made such that the material not be admitted to prove the fact asserted
Expert Opinion Exception: s.79 –Discretionary Exclusion
- Even If Admissible, Expert Evidence May Be Excluded On Discretionary Grounds
• Reliability of the field of expertise, or its applicability to the issue, or the expert’s ability to apply it
• Extent to which assumed facts are identified and proved
• Extent of the relevance of the assumed facts
•
Importance of having an expert explain to the jury . If of such common
knowledge that it would be a waste of courts time, could be excluded
under s135.
• Importance of the issue
• Validity of the reasoning process: HG v R
Velevski
v The Queen [2002] HCA (Conflicting expert evidence is to be resolved
by the jury, and opinion evidence must be based wholly or substantially
upon that knowledge. )
Facts: Velevski was charged with the murder
of his wife and kids while defence argued that the wife had murdered
her kids and then slit her own throat.
• Expert evidence from a
number of pathologists was called to determine whether the defence
scenario was possible upon examination of the wounds there was
conflicting expert evidence.
Issue: Is there a field of expertise on
self-infliction of wounds? there was also a question of whether the
experts gave evidence going beyond their expertise.
Held: Juries are entitled to and are able to evaluate conflicting expert evidence.
•
Per Gaudron J: Where conflicting evidence is based on matters of
common knowledge or experience a jury should be able to resolve the
issues (evidence of whether wife killed herself was based on common
knowledge not expertise) if it is not, then the jury can only resolve
the conflict by looking at other evidence.
• Also, s80 expressly
anticipates that an expert witness can consider matters that are within
the common knowledge of ordinary people in formulating an opinion.
•
Per Callinan, Gummow JJ: While this field is not derived from
recognised principles of medical science, it is still capable of being
the subject of expert evidence if a suitable foundation for the
witnesses training, study or experience can be found.
• The
test for “specialised knowledge” is unresolved. Gaudron J favours the
reliability approach and Gummow and Callinan JJ favour the “general
acceptance” approach???
• The court also held that the experts
went beyond observation in reaching their opinions the experts must
only use those parts of ordinary knowledge and experience that are
necessary in formulating their expert opinions however, the reception
of that evidence did not mean that the trial miscarried.
Ultimate issue and common knowledge rules abolished
s80
Evidence of an opinion is not inadmissible only because it is about:
(a) a fact in issue or an ultimate issue; or
(b) a matter of common knowledge.
- The ‘Ultimate Issue Rule’ At Common Law Has Been Largely Abolished By Section 80
•
A psychiatrist, for example, could testify as to a person’s sanity
even though that is the very issue the court must decide - witnesses
can now use words like ‘negligence’, ‘fraudulence’ etc. in their
testimony, subject to:
• Their ability to so testify
• Cross-examination
• Discretionary exclusions
• Juries being directed to make up their own minds