Expert Witness
Who is an Expert Witness. ?
In the course of investigation of a Fire ,a Fire Investigation Officer will
on occassions be called as an "Expert Witness" within a Court of
Law , I have tried to clarify this term below.
A number of legal sources offer a definition of an Expert Witness.listed below
are exerts from " Stones Legal Manual 1993 ", but what must be borne
in mind is that:
Only examining justices will decide who may be called as an Expert Witness.
Expert Opinion
2-343 Expert opinion The opinion of a witness is generally inadmissible:
He is there to relate observed facts (a). Expert witnesses may however be
called upon to state their opinion on a matter within their special knowledge
of skill, where the court itself cannot form an opinion, special study, skill
or experience being required (b).
2-344 Expert opinion may be called to assist the court in matters of legitimacy
as to whether periods of gestation could be too long or too short (a); a psychologist
may give evidence of the respective personalities of defendants based on commonly-employed
clinical tests (b); a medial witness may express an opinion whether wounds
on a body he had not seen could have been self-inflicted, assuming the facts
described by another witness who had seen the body were true (c); a policy
officer with fifteen years' experience in a traffic division who had attended
a course of accident investigation and attended to more than 400 fatal road
accidents, can give expert evidence of his theories and conclusions on an
accident (d). Voice identification is a field where expert opinion is admissible,
even though it is not an exact science (e). An expert in the production of
high quality sound recordings may give evidence as to voice identity, having
based his opinion on a comparative tape recording which he had prepared
(f). Evidence of a doctor, both of fact and opinion, may be admitted if -
(i) it is relevant to an issue in the case;
(ii) It is not hearsay;
(iii) in so far as it is evidence of opinion, it is not founded on hearsay,
and
(iv) in so far as it is evidence of opinion, it relates to matters outside
the knowledge and experience of the tribunal of fact
(g) The opinion of a witness is admissible to ascertain foreign law including
Scottish law (h) and colonial law except in the Privy Council
(i) but he must in all cases be a professional lawyer or a holder of an office
requiring and implying legal knowledge
(j) Where evidence is conflicting or obscure, the court itself will consider
the passage cited and attempt to determine its proper meaning
(k) A non-expect witness may give admissible evidence whether a person was
drunk
(l) (but not whether he was fit to drive), whether an estimate as to the value
of damage to a window was accurate
(m)Expert opinion is necessary only when the expert can furnish the court
with scientific information likely to be outside its experience; for example
a psychiatrist is not necessary to say how an ordinary person who is not suffering
from mental illness is likely to react to the stresses and strains of life
(n) or the effects of cocaine and its various methods of ingestion (o); expert
evidence on whether material is obscene is probably admissible only where
a special audience is in contemplation
(p)An expert may refer to professional treatises, tables, reports etc to refresh
his memory, but it is his evidence and not that material which is admissible
(q). When an expert witness is asked to express his opinion on a question,
the primary facts on which that opinion is based must be proved by admissible
evidence given either by the expert himself or some other competent witness.
However once such facts are proved, the expect witness is then entitled to
draw on the work (including unpublished work) of others in his field of expertise
as part of the process of arriving at his conclusion, provided he refers to
that material in his evidence so that the cogency and probative value of his
conclusion can be tested by reference to that material. Reliance on the work
of others and reference to it in evidence does not infringe the hearsay rule
in these circumstances (r).
Expert Reports
2-345 Expert reports An expert report is admissible as evidence in criminal proceedings, whether or not the person making it attends to give oral evidence in those proceedings. If the person making the report does not give oral evidence, the report shall only be admissible with leave of the court. An expert report, when admitted, shall be evidence of any fact or opinion of which the person making it could have given oral evidence (a).
For the purpose of determining whether to give leave the court shall have
regard -
(a) to the contents of the report:
(b) to the reasons why it is proposed that the person making the report shall not give oral evidence;
(c) to any risk that its admission or exclusion will result in unfairness to the accused; and
(d) to any other circumstances that appear to the court to be relevant (b).
Admissibility of expert opinion and certain expressions of non-expert opinion.
2-1152 3. Admissibility of expert opinion and certain expressions of non-expert opinion.
(1) Subject to any rules of court made in pursuance of Part I of the Civil Evidence Act 1968 or this Act, where a person is called as a witness in any civil proceedings, his opinion on any relevant matter on which he is qualified to give expert evidence shall be admissible in evidence.
(2) It is hereby declared that where a person is called as a witness in any civil proceedings, a statement of opinion by him on any relevant matter on which he is not qualified to give expert evidence, if made as a way of conveying relevant facts personally perceived by him, is admissible as evidence of what he perceived.
(3) In this section "relevant matter" includes an issue in the proceedings in question.
Evidence and the court
2-20 Evidence and the court. - The law of evidence lays down the principles
as to how facts may be proved in court and what facts may not be proved (a).
It is also prescribes standards as to the sufficiency of evidence, whether
the court can judge the weight of particular evidence to be insufficient,
prima facie or conclusive (b), and establishes requirements for certain classes
of witnesses (c). The court has therefore the primary responsibility to satisfy
itself as to admissibility of evidence and as to proof of fact which that
evidence seeks to achieve.
It is the function of the court at a criminal trial as respects of admission
of evidence to see that the accused has a fair trial according to law (d).
The court should not wait for an objection to be taken to the admissibility
of the evidence but should stop such questions itself (e). A court in a criminal
trial has a discretion to refuse to admit evidence if in its opinion its prejudicial
effect outweighs its probative value. But save with regard to admissions and
confessions and generally with regard to evidence obtained from the accused
after commission of the offence it has no discretion to refuse to admit relevant
admissible evidence on the ground that it was obtained by improper or unfair
means, for example as the result of the activities of an agent provocateur
(f).
The court will concern itself to see that it admits relevant evidence (g) and it will weigh all the relevant admissible evidence before it comes to a conclusion (h). The fact that the court has once rules a written statement inadmissible will not prevent that ruling being reversed at a later stage as further evidence emerges (i).
"Where the trial is with a jury, the judge can hear argument and decide whether or not to exercise his discretion in the absence of the jury. In a trial in a magistrates' court that is not possible. When considering the admissibility of any evidence, the magistrates must know what evidence it is proposed to tender. It they decide that it is inadmissible, they will ignore it in reaching their conclusion. In the same way, it falls on them to decide whether, on account of its prejudicial effect outweighing its probative value, certain evidence should not be given. Again they will be informed of the nature of the evidence and if they rule that it should not be admitted, they no doubt will ignore it in reaching their conclusions" (j).
The court should restrain unnecessary cross-examination on matters which are not really in issue (k).
It is for the court of trial and not for examining justices to decide whether legally admissible evidence ought to be adduced (l), although in committal proceedings examining justices may treat parts of a written statement as inadmissible (m).

