OPINION EVIDENCE

1. OPINION EVIDENCE

2. What is opinion evidence? Essentially it is evidence in the form of inferences drawn from facts by an expert or non-expert witness.

3. Exclusionary rule The general rule is that opinion evidence is not admissible because it is for the tribunal of fact (i.e. the judge in a civil trial without a jury or the jury or magistrates in criminal proceedings), and not for the witnesses, to form its opinion on the evidence The general exclusionary rule is subject to exceptions, the main two exceptions relating to the evidence of non expert witnesses and the evidence of expert witnesses

4. NON-EXPERT WITNESSES

5. Non-expert witnesses in civil proceedings(Civil Evidence Act 1972, s 3(2),(3)) (cont) Non-expert opinion evidence is admissible under CEA 1972, s.3(2) (i.e. in civil proceedings), in relation to relevant matters, for the purpose of conveying facts personally perceived by the non-expert witness to the court Where non-expert opinion evidence is admissible in civil proceedings, the effect of CEA 1972 s.3(3) is that the witness may state his opinion in relation to “ultimate issues” (i.e. the witness may state his opinion in relation to issues in the proceedings) [Note: non-experts cannot give expert evidence.]

6. Non-expert’s in criminal proceedings (common law) Non–expert opinion evidence is admissible at common law (i.e. in criminal proceedings) in relation to relevant matters, for the purpose of conveying facts personally perceived by the witness to the court Non-expert opinion evidence is notadmissible at common law (i.e. in criminal proceedings) in relation to ultimate issues (i.e., strictly, the non-expert witness should not be permitted to state his opinion in relation to issues in the proceedings; in practiceif this is permitted the judge should make clear that the issue is determined by the jury) [Note: non-experts cannot give expert evidence.]

7. Dave is charged with being drunk on an aircraft. Sheila testifies that, in her opinion, Dave had been drinking before he boarded the aircraft. Sheila testifies that she formed this opinion because when Dave boarded the aircraft she could smell alcohol on his breath, he was slurring his speech and was aggressive. Which of (i) or (ii) is/are true? (i) Sheila should not have been permitted to give opinion evidence because she is not an expert (ii) Sheila should not have been permitted to state her opinion that Dave had been drinking because her opinion was based upon facts that she had perceived They are both false

8. EXPERT WITNESSES

9. Competence to give expert evidence (common lawcriminal proceedings and CEA 1972 s.3(1) civil proceedings) Only an expert is competent (i.e., in the words of CEA 1972 s.3(1), “qualified”) to give expert evidence in criminal or civil proceedings An expert will normally have received formal training, possess formal qualifications and have had practical experience, but a person may be an expert without formal training or formal qualifications if he possesses the necessary expertise via his practical experience

10. Competence to give expert evidence (continued) • An expert is only competent to give expert evidence in his own field of expertise (one practical problem may be that a times an expert who is competent to give expert evidence in field A gives evidence which also drifts into field B) • Exceptionally a witness who is not in general terms an expert may have become an expert ad hoc in relation to the facts of the case before the court

11. Salim, a schoolboy, has recently been awarded a Boy’s Brigade first aid badge. Professor Smith is a consultant dermatologist with many years practical experience. Jack is a police officer who has attended hundreds of road traffic accidents. Which of (i) (ii) or (iii) is/are true? (i) Salim is not competent to give expert medical evidence (ii) Professor Smith is clearly competent to give expert evidence concerning cause of death by stabbing (iii) Jack cannot be competent to give expert evidence unless he is a university graduate. (i) is true

12. Compellability to give expert evidence • A competent expert is compellable but it will be exceptional for the courts to compel an expert to testify if he has no connection with the facts or history of the case

13. When is expert evidence admissible (common law criminal proceedings and CEA 1972 s.3(1) civil proceedings) Essentially, expert evidence is admissible, in civil or criminal proceedings, in relation to an issue if it provides the court with information which is likely to fall outside the ambit of its experience or knowledge (i.e it is admissible if the court requires the expert evidence in order to reach a properly informed decision,in which case it is “relevant” within the meaning of s.3(1) of the CEA 1972) but it is not admissible in civil or criminal proceedings if the court can form its own conclusions in relation to the issue without expert assistance (i.e. if it is not so required).

14. When is expert evidence admissible (common law criminal proceedings and CEA 1972 s.3(1) civil proceedings) (continued) Where expert evidence is admissible in civil proceedings under CEA 1972 s.3(1), admissibility is still subject to discretion under the CPR 1998, see below Where expert evidence is admissible in criminal proceedings, its admissibility for the prosecution is still subject to the PACE 1984 s.78 exclusionary discretion

15. Horace, is charged with dangerous driving. Witnesses of fact will testify that Horace was driving at 100 miles per hour along a wet two way single track road with passing places on a foggy day. Is the following proposition true or false? In these circumstances the evidence of experts in road traffic accidents will clearly be admissible for both prosecution and defence False

16. Sam crashes his wagon into Dawn’s house, causing serious damage to the house. Due to amnesia following the accident, Sam cannot remember what happened. Dawn is bringing civil proceedings against Sam’s employers. The parties wish to adduce the evidence of experts witnesses who have calculated the speed of the wagon from the skid marks and the nature of the damage caused to the house. Is the following proposition true or false? In these circumstances expert evidence will clearly be inadmissible False

17. Whose opinion decides the issue? The opinion of the tribunal of fact, not the opinion of the expert, decides the issue before the court (though there may be circumstances in which a court is effectively obliged to accept unequivocal expert evidence which has not been contradicted or challenged during cross-examination) It is the tribunal of fact which determines the weight of the expert evidence (e.g. where an expert has performed badly during cross-examination and, e.g., has been shown to be biased or to lack expertise, it may be that the weight of his expert evidence will be significantly reduced. Indeed, the court may even decline to accept the evidence of a single joint expert)

18. New techniques/techniques of doubtful reliability The English courts appear in general to be willing to admit expert evidence based on new techniques (reliability going to weight not admissibility; nature of directions to the jury being crucial) but there may be circumstances in which: atechnique is not sufficiently recognised for the witness to be regarded as competent to give expert evidence; a technique is so unreliable as to possess no weight (i.e. irrelevant)/or so unreliable that the judge should exclude evidence based upon it in the exercise of his exclusionary discretion; the case is based upon expert evidence in a developing field, there is a serious disagreement between the experts and the judge should withdraw the case from the jury.

19. Special warnings Where expert evidence (e.g. lip reading evidence) is of a type which is subject to difficulties (such as a risk of error) which the jury may not be aware of or may not fully understand, it will be necessary for the judge to give the jury an appropriate “special warning” (e.g. with lip reading evidence the “special warning” will normally concern the risk of error in relation to such evidence, the reasons why there is a risk of error, the fact that the witness may be honest and convincing and yet may make have made mistakes and the strengths and weaknesses of the evidence before the court, including any factors affecting its quality).

20. Clint (the claimant) is injured at work. Clint and three other witnesses of fact assert in their witness statements that Clint was injured when a lever flew off a machine that Clint was using according to the proper safety instructions and struck him in the face. Following cross-examination of Clint and his witnesses the judge finds them honest, reliable and extremely credible. Roger, a single joint expert, states that in his opinion the accident could not have occurred if Clint was using the machine according to the proper safety instructions. True/false? The judge must accept Roger’s expert opinion False

21. Expert evidence and ultimate issues in civil proceedings (CEA 1972 s.3(1), s.3(3)) Where expert evidence is admissible in civil proceedings, it is admissible in relation to ultimate issues (i.e. the expert may state his opinion in relation to issues in the proceedings), but expert evidence is only admissible in relation to ultimate issues ifthe court is likely to be incapable of forming its opinion in relation to the ultimate issue without the expert’s assistanceandthe expert possesses expertise in relation to that issue (in practice a civil court may admit such evidence but ascribe little weight to it evidence butnote that the civil courts do now possess CPR 32.1 discretion to exclude relevant evidence)

22. Expert evidence and ultimate issues in criminal proceedings (common law) Strictly, expert evidence is not admissible in criminal proceedings in relation to ultimate issues In practice, the criminal courts may often (though it seems not always) be prepared to admit expert evidence in relation to ultimate issues but it should be made clear to the jury that the decision is theirs, and they are not bound by the expert’s opinion

23. Oliver, a facial mapping expert, compares photographs of the accused with images taken from a CCTV recording of the commission of the offence (criminal damage), and forms the opinion that the CCTV evidence strongly supports the view that the accused is the offender Which one of [a] or [b] is true? [a] Oliver’s opinion evidence must not be admitted because it relates to an ultimate issue (the identity of the offender) [b] The judge may admit Oliver’s opinion evidence but should make clear to the jury that it is for them to assess the weight of the expert evidence [b] is true

24. Manoj was injured in a car crash and is bringing a negligence claim against Peter, the other driver. Anne, a single joint expert, concludes in her report that the accident was caused by Peter’s negligence. Which one of [a] or [b] is true? [a] Anne’s conclusion must be inadmissible because it relates to an ultimate issue [b] The fact that Anne’s conclusion relates to an ultimate issue does not mean that it is admissible, but it may carry little or no weight [b] is true

25. The factual basis of expert evidence in civil proceedings The expert need not have personal knowledge of the primary facts on which his opinion is based so long as they are proved by admissible evidence such as the evidence of other witnesses; or hearsay evidence (remember that the hearsay rule does not prevent the admission of evidence in civil proceedings (CEA 1995, s.1), though the weight of such evidence may be limited (CEA 1995, s.4)); or real evidence produced by a machine

26. The factual basis of expert evidence in criminal proceedings The expert need not have personal knowledge of the primary facts as long as they are proved by admissible evidence such as the evidence of other witnesses; or hearsay evidence admissible under an exception to the hearsay rule (if no hearsay exception applies, the primary facts cannot be proved in criminal proceedings by the expert’s inadmissible hearsay evidence); or admissible evidence produced by a machine (remember CJA 2003 s.129 re machines).

27. CJA 2003 s.127 (criminal proceedings) An expert may base an opinion or an inference on a statement which was prepared for the purposes of criminal proceedings (or for those of a criminal investigation) by a person who had or may reasonably be supposed to have had personal knowledge of the matters stated if notice (as required by rules of court, i.e. by CrimPR Part 24) is given that the expert will (either in oral evidence or in evidence given under under CJA1967 s.9) base an opinion or an inference thereupon.

28. CJA 2003 s.127 (continued) Where an expert’s evidence is based upon such a statement, the statement is treated as evidence of what it states. The court may (upon application by a party) order that it is not in the interests of justice for section 127 to apply.

29. CJA 2003 s.127 (continued) In deciding whether to order that it is not in the interests of justice for s.127 to apply, the matters the court should consider include the expense of calling the person who prepared the statement, and whether he could give relevant evidence that the expert could not give; and whether he can reasonably be expected to remember the matters stated well enough to give oral evidence thereof.

30. Professor Adams, an expert witness, states in his report that, in his opinion, a fragment of glass in the shoe of the accused (charged with arson) came from a broken window at the scene of the crime. The Professor did not carry out tests on the glass himself, the tests being carried out by Roger, his assistant, the Professor’s opinion being based on a statement that Rolf prepared for the proceedings. Which of (i) or (ii) is/are true? (i) Rolf’s statement must be inadmissible because it is a hearsay statement (ii) The professor’s opinion must be inadmissible because it is based on hearsay evidence They are both false

31. Research of others (civil and criminal proceedings) In civil and criminal proceedings, expert witnesses may rely upon the research of others (i.e. textbooks, articles etc) in forming their opinions (rule preserved in criminal proceedings by s.118 CJA 2003) Experts should indicate which articles etc they have relied upon in order that the weight of their evidence may properly be evaluated

32. Professor Adams, an expert witness, states in his report that, in his opinion, a fragment of glass in the shoe of the accused (charged with arson) came from a broken window at the scene of the crime. In forming his opinion the professor relied upon information in textbooks and articles Which one of [a] or [b] is true? [a] The professor should refer to the relevant textbook’s and articles in his report [b] The professor’s opinion must be inadmissible because it is based on hearsay evidence [a] is true

33. Failure to adduce expert evidence Where expert evidence is required by the court in order to resolve an issue in relation to which a party bears the legal burden of proof and the relevant party does not adduce expert evidence in relation to the issue, this may result in the party failing to discharge the relevant burden.

34. Jonny books a “learner rock climbing holiday” and is injured when he falls from a climbing wall. He is bringing a negligence claim against LRCH (the holiday company) and claims that the climbing wall was too difficult for a learner. Other than medical evidence, neither party adduces any expert evidence. Is the following proposition true or false? The judge may properly rule in favour of LRCH upon the basis that, in the absence of expert evidence, Jonny has failed to establish that the climbing wall was too difficult for a learner and has, thus, failed to establish that LRCH was negligent. True

35. CIVIL PROCEDURE RULES 1998 AND EXPERT EVIDENCE (CPR Part 35)

36. When does CPR Part 35 apply? CPR Part 35 applies to experts who are instructed to give or prepare evidence for the purposes of court proceedings (CPR 35.2) It does not apply to an expert who is merely instructed to advise (i.e. to comment on another experts report, it not being intended to call him or adduce his evidence) It does not apply to an expert who is merely called as a witness of fact (e.g. a consultant who was present at an operation that resulted in a clinical negligence claim against a colleague)

37. Admissibility of expert evidence under the CPR 1998 The court’s permission is required to adduce expert evidence (CPR 35.4) [Note: the expert evidence must, as was seen above, be admissible under s.3(1) CEA 1972.] Expert evidence should be restricted to that which is reasonably required (CPR 35.1) Permission should only be granted in relation to a specified field and, if practicable, a specified expert (CPR 35.4) Nature of the expert evidence required will depend on the facts of the case (e.g. value/complexity)

38. Admissibility of expert evidence under the CPR 1998 (cont) If court order giving permission to call expert does not identify a named expert then permission is not required to change expert. Where permission to change expert is required and is given, it appears that it should be conditional upon original report being disclosed.

39. Single joint expert (CPR 35.7) The court may direct that expert evidence in relation to an issue be given by a single joint expert (this will depend upon matters such as the value and complexity of the case) If the parties cannot agree on a single joint expert the court may select one from a list provided by the parties or may direct another method of selection Where evidence concerning several expert fields is to be given by a single joint expert, he should be the expert in the dominant field and should annex or incorporate the reports of other experts into his report

40. Single joint expert (CPR(continued)) Where a single joint expert is appointed the parties may still instruct experts to advise (though the costs may not be recoverable) The single joint expert is instructed by all of the parties who wish to submit expert evidence, the parties sending copies of their instructions to each other (if possible, they should agree joint instructions) A single joint expert should only attend a meeting or conference that is not a joint meeting or conference if the parties agree or the court so directs

41. Single joint expert (CPR) continued A single joint expert must produce a single report even where the instructions contained conflicting facts or allegations (if this results in the expert forming different opinions, the report may need to contain these as it is for the court, and not for the expert, to determine the facts). A single joint expert must serve his report on the instructing parties simultaneously Where a single joint expert has been appointed the court may still, in appropriate circumstances, subsequently permit a party to adduce his own expert evidence

42. Single joint expert (CPR) continued The court may permit a single joint expert to be called to amplify his report/ for cross-examination by the parties (though it should not normally be necessary for a single joint expert to be called and, in general, written questions should be put to a single joint expert before a request is made for permission for him to attend for cross-examination). It is the opinion of the judge, not that of the single joint expert, which determines the issue before the court (though the uncontradicted opinion of a high quality and unbiased single joint expert may well, in practice, be decisive).

43. In clinical negligence proceedings against Newtown Healthcare Trust (NHT), NHT intend to call W, a consultant anaesthetist who attended operation, as a witness of fact. The parties intend to call their own medical experts in relation to causation and their own experts in relation to quantum (concerning the cost of adaptations to the claimant’s home and the cost of long term medical care) Which of (i) or (ii) is/are true? (i) The permission of the court under CPR Part 35 will be required to call W because he is an expert (ii) The parties are entitled to call their own experts in relation to both causation and quantum They are both false

44. In civil proceedings in negligence that have been allocated to the fast track, Dr Jones, an experienced general practitioner, is appointed as a single joint expert. The defendant wishes to instruct Dr Smith, another general practitioner, to comment on Dr Jones’, report but does not intend to call Dr Smith or to adduce his expert evidence in the proceedings. Which of (i) or (ii) is/are true? (i)The defendant will require the court’s permission in order to instruct Dr Smith (ii) The defendant will require the court’s permission if he subsequently wishes to adduce a report from Dr Smith as evidence in the proceedings (ii) is true

45. Expert’s duty to the court (CPR 35.3 and Protocol for the Instruction of Experts to Give Evidence in Civil Claims ) The expert’s duty is to help the court, this duty overriding his duty to the person instructing/paying him Expert evidence should be independent and should not be influenced by the pressures of litigation The expert should provide objective and unbiased opinion and should not take the role of an advocate The expert should consider all material facts including those which may detract from his opinion

46. Expert’s duty to the court (continued) The expert should make clear when an issue falls outside the ambit of his expertise The expert should make clear when he is unable to form a definite opinion If the expert changes his view on a material matter after producing his report he should communicate this to all the parties and, where appropriate, to the court. An expert should inform the instructing party if his instructions are unacceptable (e.g. outside his expertise, deadlines too tight, instructions unclear) An expert should not be instructed on a contingency fee basis

47. Expert’s duty to the court (continued) The expert may make a written request to the court for directions to assist him in performing his functions without notifying the parties (CPR 35.14) (he should normally discuss the matter with the instructing parties before making such a request and should not inform the court about privileged or without prejudice communications) A single joint expert’s overriding duty is to the court; he owes an equal duty to all instructing parties

48. Paul is bringing a clinical negligence claim against Newtown Healthcare Trust. Paul cannot afford to instruct a medical expert, bur Dr Parker is willing to be instructed on a contingency fee basis. Which one of [a] or [b] is true? [a]Dr Parker should not be instructed on a contingency fee basis if he is to be a single joint expert but may be instructed on a contingency fee basis if the parties are instructing their own medical experts. [b] Dr Parker should not be instructed on a contingency fee basis even if the parties are instructing their own medical experts [b] is true

49. Employed experts and friends (civil) It seems that an expert employed by a party may be permitted to give expert evidence (though not as a single joint expert) if he understands his duty to the court, but the weight of his evidence may be affected The Court of Appeal has suggested that experts should state in their reports that they have no conflict of interest other than any they have disclosed in their reports, that they do not consider that any disclosed interests affect their suitability and that they will advice the instructing party of any change in circumstances

50. Directing a party to provide information (CPR 35.9) The court may direct a party to give another party information (e.g. details of tests, experiments etc) which is accessible to the former but which is not reasonably accessible to the latter