Expert Evidence
Experts
The general principles of law applicable to expert evidence apply in criminal and civil matters. An expert who is shown to have expertise in a particular area may offer expert opinion on matters in issue. The underlying facts which are the basis of the opinion must be proved or must be explicitly stated to be assumed.
An expert is someone who furnishes information that is outside the ordinary experience and knowledge of judge and jury. Whether or not a person is an expert is determined by the judge
Most experts will have a form of professional qualification in their areas of expertise. However, an expert need not be formally qualified. He need not profess a particular calling or regularly undertake a particular activity.
Role
The witness shall not give evidence on the ultimate issue in the trial. This is for the jury or the judge if there is no jury function of the expert is to provide expert knowledge to assist the trial of facts and allow the judge and/ or jury to come to their conclusion. on the facts, The distinction may be difficult to draw in some cases.
It is suggested that the rule has diminished in modern times with a great increase in the nature of expertise available on various issues. The rule can be used to exist in practice may be somewhat reduced in scope.
An accused shall not call an expert witness or adduce expert evidence unless leave to do so has been granted.
Ordinary Human Experience
The courts have been reluctant to allow psychiatric and psychological evidence in relation to issues that are more appropriately assessed by a judge and jury as within ordinary experience. It is said that the expert should not give evidence as to the ultimate issues in the case. Matters of motive and intention are deemed matters of ordinary human experience by which the jury is the arbiter f facts.
In particular, where issues of intention and motivation are central to the issues in the case, the court will be reluctant to allow expert evidence on these issues directly, as its effect would be to usurp the jury’s determination. Expert witness evidence is not generally permitted in given in relation to the credibility of the witnesses.
This is not to say that psychiatric and psychological evidence is not commonly heard in criminal cases. For example, the courts recognise that in some cases, expert evidence may illuminate a particular abnormality relevant to the reliability of the defendant’s evidence or confession.
Qualifications
The expert witness must give evidence of his qualifications in the particular area. It must be established to the satisfaction of the judge. The judge will consider whether, by virtue of training and/or experience, he is qualified as an expert to give the type of evidence concerned,
An expert will not necessarily be of required expertise in a well-known field of endeavour. Expert evidence has been allowed in respect of abilities acquired in unconventional means and in unconventional areas.
Anti-Terrorist Offences
Separately a number of acts in the antiterrorist and antigang land areas have allowed for the admission of evidence of an opinion by senior police officers as to membership of gangs or unlawful organisation. Notwithstanding that the opinion relates directly to the subject matter of an offence and there are limitations on cross-examination as the sources, the provisions have been upheld in a number of challenges on constitutional and human rights grounds.
The expert witness should be independent and with a primary obligation to the court. It should state the facts or assumptions on which an opinion is based.
If there isn’t sufficient information on which to base an opinion, he should make it clear that this is the case.
If the matter arises which is outside his areas of expertise, the expert witness should so declare if he changes his mind after confirming with other witnesses or at any stage this should be communicated to the other side and to the court.
Pre-Trial Disclosure by Defence
The Criminal Procedure Act 2010 makes provision for disclosure by the defence prior to trial of expert evidence. “Expert evidence” means evidence of fact or opinion given by an expert witness, and an “expert witness” means a person who appears to the court to possess the appropriate qualifications or experience about the matter to which the witness’s evidence relates.
The defence must obtain leave of the court before calling expert evidence. It must give at least 10 days prior notice of its intention to call expert evidence of the trial. The notice must be given at least 10 days before the scheduled trial date.
The notice must be written and specify the particulars of the witness. It must include any reports prepared by the expert witness in relation to matters relevant to the case including details of analysis carried by or on behalf of or laid down by the expert witness or summary of findings of the expert witness.
If the report is not given with the notice, the court may nonetheless allow it to be given as evidence if it is satisfied that the accused took all reasonable steps to secure the report or summary before giving the notice.
Requirement for Leave
The court shall grant leave to call expert evidence on behalf of the defence if it is satisfied that the expert evidence to be offered satisfies the requirements of the law of evidence and that the requirements for notice have been complied with or where the notice was not given it would not know all the circumstances have been reasonably possible for the defence to have done so or the prosecution has offered expert evidence and the matter arose that it is not reasonably possible for the defence to have anticipated and it would be in the interest of justice for that matter to be further examined in order to establish its relevance.
The prosecution has the right to be heard on the above application. Where the court grants leave the prosecution is to be given a reasonable opportunity to consider the report or summary.
The requirement has withstood High Court challenge on the basis of a constitution and the European convention on human rights. It is claimed that interfered with the ability of the defence to test prosecution evidence and in particular, the prosecution was not subject to an equivalent requirement. The High Court decided that the provision was balanced and that the judge could use discretionary powers to avoid unfairness to the accused. The matter had not come before the Supreme Court.
“Expert evidence” means evidence of fact or opinion given by an expert witness, and an “expert witness” means a person who appears to the court to possess the appropriate qualifications or experience about the matter to which the witness’s evidence relates.
Where the defence intends to call an expert witness or adduce expert evidence, whether or not in response to such evidence presented by the prosecution, notice of the intention shall be given to the prosecution at least 10 days prior to the scheduled date of the start of the trial.
The notice shall be in writing and shall include the name and address of the expert witness, and any report prepared by the expert witness concerning a matter relevant to the case, including details of any analysis carried out by or on behalf of or relied upon by, the expert witness, or a summary of the findings of the expert witness.
Grant of Leave
The court may grant leave to call an expert witness or adduce expert evidence even if no report or summary of the findings are included as required if the court is satisfied that the accused took all reasonable steps to secure the report or summary before giving the notice.
The court shall grant leave to call an expert witness or adduce expert evidence, on application by the defence, if it is satisfied that the expert evidence to be adduced satisfies the requirements of any enactment or rule of law relating to evidence and that—
- the above conditions have been complied with,
- where the notice was not given at least 10 days prior to the scheduled date of the start of the trial, it would not, in all the circumstances of the case, have been reasonably possible for the defence to have done so, or
- where the prosecution has adduced expert evidence, a matter arose from that expert’s testimony that was not reasonably possible for the defence to have anticipated and it would be in the interests of justice for that matter to be further examined in order to establish its relevance to the case.
The prosecution shall be heard in the application.
Where the court grants leave under this section, the prosecution shall be given a reasonable opportunity to consider the report or summary before the expert witness gives the evidence or the evidence is otherwise adduced.