19: Opinion Evidence

Question 1

What is the general rule for opinion evidence?

Answer 1

Witnesses may only give evidence on facts they personally perceive + not evidence of their opinion, i.e. inferences drawn from facts. Inferences to be drawn from evidence were for the jury.

Question 2

What is the EXCEPTION for the general rule for opinion evidence?

Answer 2

EXCEPTION:

1. Non-experts = Statement of opinion on any matter not calling for expertise, if made by W conveying relevant facts personally perceived = admissible as evidence of what he perceived.
2. Experts = statement of opinion calling for expertise may be made by W qualified. Evidence may be accompanied by animations to illustrate.

If objection to expert opinion made = party offering evidence proves admissibility.

Question 3

What is the non-expert opinion evidence?

Answer 3

Opinion may be given by W on matter not calling for expertise to convey facts perceived by him. Identification W NOT required -) give description of offender or other person, leaving tribunal of fact to decide if description its D, MAY express opinion D is person he saw. On charge of driving when unfit through drink – fitness of D = calls for expertise, but non-expert may give evidence of his impression as whether D had a drink provided he describes facts on basis he formed that impression.

Question 4

EXPERT OPINION EVIDENCE

Competence

What does this mean?

Answer 4

Must have expertise to suitable calibre. Whether W properly qualified = question for court. Mere self-certification = insufficient. May be necessary to hold voir dire, but can be done on written material. If W gives expert evidence, judge MAY remove expert status + limit evidence to factual matters.

Question 5

EXPERT OPINION EVIDENCE

Matters calling for expertise = ​

Answer 5

Expert opinion evidence may only be received on subject calling for expertise which lay person could not be expected to possess to degree sufficient to understand evidence. If tribunal of fact can form own opinion without assistance of expert, expert opinion = inadmissible because unnecessary

Jurors MAY receive assistance on matter within own experience + knowledge if provided by someone who had more time + better facilities to consider that matter than it would be practicable to afford to them.

Question 6

EXPERT OPINION EVIDENCE

Opinions on ultimate issues =

Answer 6

An expert IS allow to express opinion on an ultimate issue provided actual words used are not the same as those used when issue falls to be considered by court. BUT – experts shouldn’t usurp role of fact-finder as ultimate decision maker. Psychologist may give evidence of opinion D might be disposed to making unreliable confession, but not find confession unreliable.

Question 7

Duty of experts = Expert MUST

Answer 7

help court achieve OO by giving: objective, unbiased opinions, assisting with court directions + any significant failure. This duty overrides obligation to person instructing him/who pays him, he must:

1. Define are of expertise in report + when giving evidence;
2. Draw court’s attention to any question outside his area of expertise
3. Inform all parties + court if his opinion changes from that in a report.

Question 8

Function + weight of expert evidence = Misdirection to tell jury that expert evidence must be accepted. When expert evidence given on ultimate issue, MUST

Answer 8

tell jury that they are not bound by opinion + issue for them to decide, no requirement warning conveyed in a particular way. But if expert evidence is rejected by jury, it must be rejected for a reason.

Question 9

Function + weight of expert evidence

On diminished responsibility, 2 principles:

Answer 9

1. If no other circumstance to consider, uncontradicted medical evidence favourable to D should be accepted by jury + directed this; and
2. If other circumstances to consider, the medical evidence though uncontradicted, must be assessed in light of the circumstances.