19. Opinion evidence and experts Flashcards
What is the general rule on opinion evidence?
Witnesses may only give evidence of facts they personally perceived and not evidence of their opinion (i.e. evidence of inferences drawn from such facts). THERE ARE TWO EXCEPTIONS
Drawning a distinction between facts and inference is sometimes difficult to see.
a gynaecologist who had carried out an abortion on a 15½ year old had stated that she and her stepfather, who had accompanied her, ‘had a rather closer relationship than would be expected’. It was held that this was a statement of fact, not opinion, being a description of the interaction between them that he had observed.
it was held that evidence of tests showing the speed at which the handwritten notes of disputed interviews had been made, and whether they could have been written in the time claimed by officers, was no more opinion evidence than evidence of the timing of a given journey in order to test an alibi.
it was held that a witness was entitled to explain how VAT carousel frauds operate but should not have expressed an opinion on the issue before the jury, namely whether D would have known that they had participated in a fraud.
What exceptions are there to the general rule on opinion evidence?
(a) Non-experts. A statement of opinion on any matter not calling for expertise, if made by a witness as a way of conveying relevant facts personally perceived by him or her, is admissible as evidence of what the witness perceived. (i.e. as a compendious means of conveying facts perceived by the witness, such as:
i. giving the opinion that the accused is the person the witness saw, or
ii. an opinion to identify an object,
iii. handwriting,
iv. a voice,
v. a person’s age,
vi. appearance of a person’s health, mind, or emotion,
vii. speed,
viii. weather,
ix. passage of time,
x. drunkenness (so long as the reason for that impression is given),
xi. description of an object to identify it as a drug.
xii. Could even be given in respect of the value of an object, except for less commonplace objects like art)
(b) Experts. Subject to compliance with CrimPR Part 19 (expert evidence), a statement of opinion on any relevant matter calling for expertise may be made by a witness qualified to give such an expert opinion (the evidence may be accompanied, where appropriate, by animations to illustrate the opinion. Whether such reconstruction evidence can assist can only be decided on a case-by-case basis, but will be inadmissible in the absence of sufficiently reliable and precise factual foundations).
When should such objections be dealt with where there is an objection to expert evidence?
It is important that such objections are dealt with before the evidence is given.
What should happen where an objection to opinion evidenec is made?
It is for the party proferring the evidence to prove its admissibility.
What will a judge do regarding expert evidence where no challenge to its admissibility is made?
Unless the admissibility is challenged, the judge will admit the evidence as sufficient safeguards are provided by the rules on pre-trial disclosure.
An objection to the admissibility of expert opinion evidence will necessarily fail if the witness is not an expert and expresses no expert opinion (Foulger [2012] EWCA Crim 1516, where the witness was not an expert communications data investigator but simply put otherwise relatively complicated telephone data into a more user-friendly format, using charts, maps and summaries).
What should those instructing expert witnessess satisfy themselves of?
Of the expert’s expertise and engage one of a suitable calibre. The crown must take all necessary steps to esnrue that inappropriate expert witnesses are not called.
Also should have regard to if there are any requirements of statute (i.e. has to be a registered medical practitioner e.c.t.).
What do courts need to do in regard to expert testimony?
Ensure that the expert’s testimony is truly coming from expertise. Mere self-certification is insufficient.
A person does not become competent as an expert merely because employed by a particular organisation, but will be competent, of course, if the organisation only uses qualified experts.
How may it be decided whether a person is an ‘expert’?
Via a voir dire, though in the vast majority of cases the judge will be able to make the decision on the basis of written material.
What burden is on the defence re expert witneses?
The burden is on them to make an application to contest the competence of an expert in a voir dire.
What can the court do where an expert witness gives expert evidence?
Should the need arise, they can remove the witness’s expert status and limit the evcidence to factual matters.
What may an expert’s competence or skill come from?
Formal study or training, expereince, or both.
Where can a police officer be competent to give expert evidence?
a police officer with qualifications and experience in accident investigation was allowed to give evidence, on a charge of causing death by dangerous driving, as to how an accident occurred.
A police officer is competent to give expert evidence of the practices, mores and associations of gangs (if admissible as bad character evidence) if the officer has made a sufficient study, whether by formal training or through practical experience, to acquire a balanced body of specialised knowledge not available to the jury; simple, and not necessarily balanced, anecdotal experience will not suffice.
What can a doctor do to become an expert where they are not an expert in certain matters?
a doctor was allowed to prove the conversion of figures in an analyst’s certificate into the amount of alcohol consumed by D, although not an expert in such conversion, and to prove the rate of bodily destruction of alcohol, HAVING REFRESHED HIS MEMORY FROM A BMA PUBLICATION.
What is the relevance of emergency treatment as a doctor for expert witness status?
A medical orderly with much experience in the treatment of cuts and lacerations was insufficiently qualified to express an opinion as to whether an inch-long cut to the forehead had been caused by a blunt instrument rather than a head-butt.
However, in Francis [2013] EWCA Crim 123, in contrast, it was held that a doctor who was not a forensic pathologist, but who had spent ten years in emergency medicine and would have dealt with many thousands of cases of lacerations and cuts, had properly been allowed to express an opinion that it was impossible that certain injuries had been caused by a pin and were far more likely to have been caused by a sharp blade.
What specific statement surrounding case worker expert status is there?
In Brecani [2021] EWCA Crim 731, in disagreement with the Divisional Court in DPP v M [2020] EWHC 3422 (Admin), the Court of Appeal held that the findings of case workers in the Home Office Competent Authority that a person has been trafficked for the purposes of exploitation are not admissible because such workers, ALTHOUGH LIKELY TO GAIN EXPERIENCE IN THE TYPE OF DECISION-MAKING THEY ROUTINELY TAKE, ARE NOT EXPERTS IN HUMAN TRAFFICKING OR MODERN SLAVERY.
Is it necessary that skill or expertise is gained through business for expert status?
There is no decision which requires that the evidence of a man who is skilled in comparing handwriting, and who has formed a reliable opinion from past experience, should be excluded because his experience has not been gained in the way of his business. It is, however, really unnecessary to consider this point; for it seems … in the present case that the witness was not only peritus, but was peritus in the way of his business.
(in the context of the below:
In Silverlock [1894] 2 QB 766, a solicitor, who had for ten years studied handwriting and on several occasions compared handwriting professionally, was allowed to give expert evidence that an advertisement was in D’s handwriting)
On what subjects will expert evidence be received?
Expert opinion evidence may only be received on a subject calling for expertise, which a lay person, such as a magistrate or a juror, could not be expected to possess to a degree sufficient to understand the evidence given in the case unaided.
If the tribunal of fact can form its own opinion without the assistance of an expert, the matter being within its own experience and knowledge, expert opinion evidence is inadmissible because it is unnecessary
Thus a psychologist or other medical expert will not be permitted to give an opinion on the likely deterioration of memory of an ordinary witness (Browning [1995] Crim LR 227).
On the other hand, the unlikelihood of the coincidence that a number of complainants all suffered from false memory of sexual assault is a matter calling for expert evidence, being outside the experience of the jury
Although a witness’s ability to remember events will ordinarily be well within the experience of jurors, in rare cases in which a witness gives evidence of an event, said to have occurred at an early age, and the evidence is very detailed and contains a number of extraneous facts, an appropriately qualified expert may give evidence that it should be treated with caution and may well be unreliable, because recall of events during ‘the period of childhood amnesia’, which extends to the age of about seven, will be fragmented, disjointed and idiosyncratic rather than a detailed narrative account.
In the absence of such expert evidence, which is likely to be outside the knowledge and experience of the jury, there is a danger that the jury may find the detailed account more convincing than they safely should, because detail normally enhances credibility to the ear of the listener.
Key question for memory (and everything) therefore is: is it within the knowledge/experience of the jury/mags?
What considerations are there for expert evidence from counsellors?
It will only be in the rarest of cases that expert evidence about counselling techniques will be admissible, e.g., where they may have affected the value of the factual evidence of the counsellor.
Counsellors may give non-expert evidence as to recent complaint, i.e. evidence of fact that a complaint was made at the time of the events or shortly thereafter (see F6.32), provided that the judge makes plain to the jury that it is not evidence of the truth of the complaint.
If there were obvious signs of distress when the complaint was made, evidence of such demeanour may also be given (see also F1.16 and F5.11).
A counsellor may not express any views as to the truth or otherwise of the allegations or the reliability of the complainant.
Nor should a counsellor use over-emotive language. A counsellor should use objective language and avoid saying anything that can be construed as subjective comment or a statement of personal opinion.
What considerations are there for expert evidence for cell siting?
Evidence relating to calls made or received by mobile phones and cell siting, i.e. the location of mobile phone masts through which calls have been routed, will often be drawn from computerised records of the mobile phone service providers as to the date, time and duration of calls and as to the cell sites in question.
However, expert evidence will usually be necessary as to whether, and if so to what extent, the fact that a call was routed through a particular cell site is consistent with the phone and its user having been at a particular location.
When may expert evidence be given where there is a matter within a jury’s own experience and knowledge?
In some cases, it seems that jurors may receive assistance on a matter within their own experience and knowledge if it is provided by someone who has had more time and better facilities to consider that matter than it would be practicable to afford to them
(see Clare [1995] 2 Cr App R 333, where an officer who did not know D but had viewed a video recording about 40 times, examining it in slow motion and rewinding and replaying it as frequently as was necessary, was permitted to give evidence of identification based on a comparison between the video images and contemporary photographs of D).
This principle may explain why, although the assessment of age is within the normal experience and knowledge of juries (Land [1999] QB 65), expert opinion of age is also admissible
In Ulas [2023] EWCA Crim 82, where identification was in issue, an officer was allowed to give evidence that he had viewed stills from CCTV footage of the incident in question and that two days later he had encountered someone whom he recognised as one of the suspects seen in the stills. Three days after that, he attended an identification parade and identified D as the man he had encountered.
The decision extends in two ways the principle established in Clare.
First, the comparison was between recorded images and the appearance of an actual person, rather than images in photographs.
Secondly, the officer’s evidence was simply that he had reviewed the CCTV stills, rather than spending a substantial amount of time viewing and analysing them.
It was held that it was open to the trial judge to infer that the officer had spent time viewing and analysing the images and had thereby acquired a degree of special knowledge. It was also held that the amount of time or study required to demonstrate the acquisition of special knowledge depends on the facts: a case involving a large number of images and a number of different individuals was different from the present case, where the images involved only three suspects.
What matters (i.e. specific individual circumstances) may call for expert evidence?
The subjects calling for expertise, which are so diverse as to defy comprehensive classification, include a variety of medical, psychiatric, scientific and technological matters, and questions relating to standards of professional competence. Specific examples include:
- accident investigation and driver behaviour (Dudley [2004] EWCA Crim 3336);
- age, in the absence of documentary or other reliable evidence (R (I) v Secretary of State for the Home Department [2005] EWHC 1025 (Admin); Re N (a child) (residence order) [2006] EWHC 1189 (Fam));
- ballistics;
- blood tests;
- breath tests and blood/alcohol levels (sometimes including back-calculations thereof, i.e. calculation of the amount of alcohol eliminated in the period between driving and providing a specimen, in order to show that the level was above the prescribed limit at the time of driving: see Gumbley v Cunningham [1989] AC 281);
- firearms discharge residue (George (Barry) [2007] EWCA Crim 2722; Joseph [2010] EWCA Crim 2580; George (Dwaine) [2015] EWCA Crim 2507; Olive [2022] EWCA Crim 1141— evidence of the finding of such residue may be admissible as part of a body of circumstantial evidence notwithstanding that there are only two particles, the lowest level on the scale used by expert analysts, and may have been present by reason of contamination by firearms officers);
- forgeries;
- handwriting identification (including the analysis of indented impressions of handwriting, left on one document as a result of writing on another, and revealed by Electrostatic Detection Apparatus (ESDA): see Wellington [1991] Crim LR 543);
- fingerprint identification (see F19.36);
- ear-print identification (Dallagher [2002] EWCA Crim 1903; Kempster (No. 2) [2008] EWCA Crim 975; see F19.38);
- footwear marks (T [2010] EWCA Crim 2439; Dickson [2023] EWCA Crim 1002);
- voice identification (see F19.25);
- identification by facial mapping (Stockwell (1993) 97 Cr App R 260; Hookway [1999] Crim LR 750; see F19.22), expert evidence of which may form the basis of a conviction (Mitchell [2005] EWCA Crim 731);
- facial identification by video superimposition (Clarke [1995] 2 Cr App R 425);
- ‘reverse projection’, the technique of superimposing one CCTV recording upon another as a means of comparing, e.g., the height of the individuals shown (Barnes [2012] EWCA Crim 1605);
- gangs, their way of operating, language and culture (Myers v The Queen [2015] UKPC 40; Dixon-Kenton [2021] EWCA Crim 673);
- genetic fingerprinting (the technique whereby a human cell taken from a sample of blood, saliva, semen or hair is analysed to reveal a person’s DNA or genetic ‘fingerprint’: see F19.28);
- the physical signs of child sexual abuse (S [2012] EWCA Crim 1433);
- ‘shaken baby syndrome’ (Henderson [2010] EWCA Crim 1269, considered at F11.44 and F11.48);
- Sudden Infant Death Syndrome (SIDS) (Cannings [2004] EWCA Crim 1, considered at F5.18);
- insanity;
- automatism;
- diminished responsibility;
- the competence of a medical practitioner (Whitehead (1848) 3 Car & Kir 202: expert opinion evidence as to the state of knowledge and skill of a physician as shown by his treatment of the case in question).
Can an expert opinion be given as to the ultimate issue?
Technically no, but in practice the rule is largely ignored, or treated as being of only semantic effect, so that an expert is allowed to express an opinion on an ultimate issue, provided that the actual words the expert employs are not noticeably the same as those which will be used when the issue falls to be considered by the court.
Experts should not usurp the role of the fact-finder as the ultimate decision-maker on matters that are central to the outcome of the case. Thus a psychologist may give evidence of opinion as to why the accused might be disposed to make an unreliable confession but is not entitled to assert that the confession made is in fact unreliable.
Seems to be you could say
i) In her view, he was suffering from an abnormality of mental functioning that arose from Schizotypal Disorder and Emotionally Unstable Personality Disorder, both being recognised medical conditions.
ii) In her view, his mental disorder would have substantially impaired his ability to form a rational judgment and to exercise self-control at the relevant time; and, in her view, that would have been a significant contributory factor in causing him to act in the way he did at the time.
a case in which a consultant surgeon was charged with manslaughter by gross negligence and experts had given evidence that D had been ‘grossly negligent’ and had also used other descriptions such as ‘very bad practice’ and ‘recklessness’. It was held that although the jury had been told that they were not bound by the views of the experts on the ultimate issue, the experts had failed to give explanations for the terminology of many of their opinions and therefore there was a danger that the jury may have merely accepted their conclusions.
See the below for the explanation of the rule:
“I think it would be wrong to ask the direct question as to whether any particular cards tended to corrupt or deprave, because that final stage was a matter which was entirely for the justices. No doubt, however, in such a case the defence might well put it to the witness that a particular card or cards could not corrupt, and no doubt, whatever the strict position may be, that question coming from the defence would be allowed, if only to give the defence an opportunity of getting an answer ‘No’ from the expert.
… I myself would go a little further in that I cannot help feeling that with the advance of science more and more inroads have been made into the old common-law principles. Those who practise in the criminal courts see every day cases of experts being called on the question of diminished responsibility, and ALTHOUGH TECHNICALLY THE FINAL QUESTION ‘DO YOU THINK HE WAS SUFFERING FROM DIMINISHED RESPONSIBILITY?’ IS STRICTLY INADMISSIBLE, IT IS ALLOWED TIME AND TIME AGAIN WITHOUT ANY OBJECTION.”
What process can an expert go through?
An expert can apply to become a certified expert witness through the Expert Witness Institute. Certification assesses all the core competencies required of an expert witness and recognises those who can demonstrate excellence in report writing, discussions between experts and giving oral evidence in court. Certified experts commit to undertake continuing professional development and are required to be re-assessed every five years.
What duty does an expert witness owe?
They must help the court achieve the overriding objective by giving objective, unbiased opinon matters within their areas of expertise and by actively assisting the court in fulfilling its duty of case managemnet, in particular by complying with court direction and at once informing the court of any significant failure to take any steps required by such a direction.
This duty includes an obligation:
(a) to define his or her area or areas of expertise in the report and when giving evidence,
(b) when giving evidence, to draw the court’s attention to any question to which the answer would be outside the expert’s area or areas of expertise,
(c) to inform all parties and the court if his or her opinion changes from that contained in a report served as evidence or given in a statement.
Also te duties set out in the Ikarian Reefer apply, and also those set out for experts giving evience involving children.
The fact that an expert was involved during an investigation will not necessary amount to partiality or a lack of independence.
The duty of the expert witness is ‘to furnish the judge or jury with the necessary scientific criteria for testing the accuracy of their conclusions, so as to enable the judge or jury to form an independent judgement by the application of those criteria to the facts proved in evidence’
This duty overrides any duty owed to those instructing.
What is the function and wieght of expert evidence?
The duty of the expert witness is ‘to furnish the judge or jury with the necessary scientific criteria for testing the accuracy of their conclusions, so as to enable the judge or jury to form an independent judgement by the application of those criteria to the facts proved in evidence’, and so therefore it is a miscredition to tell the jruyt that expert eivdnece hsould be accepted if uncontradicted.
Expert evidence should be apporoached critically and can be rejected even if uncontradicted.
Should be made clear that any conclusion on the ultimate issue can be rejected.
There should be (after the usual directions and appropriate stress on the need for a jury to consider all the evidence) a direction of the following kind: ‘Where, as here, there is no dispute about findings made by an expert you would no doubt wish to give effect to them, although you are not bound to do so if you see good reason to reject them.’
It has also been held that it is wrong to direct a jury that they may disregard scientific evidence when the only such evidence adduced on a particular question dictates one answer and only a scientist is qualified to answer that question.
The principles of this are:
(a) if there were no other circumstances to consider, unequivocal, uncontradicted medical evidence favourable to an accused should be accepted by a jury and they should be so directed; and
(b) where there were other circumstances to consider, the medical evidence, though it be unequivocal and uncontradicted, must be assessed in the light of the other circumstances.
