OVERVIEW
8.1 A major issue at a criminal trial which affects both the accused and the witness with an intellectual disability is the perceived reliability of their evidence. Even if a witness is found competent to give evidence or an accused is found fit to be tried, questions may still be raised (justly or unjustly) about the reliability of his or her evidence, including evidence originating outside the trial, particularly confessions. It is important that juries do not either dismiss the evidence of people with an intellectual disability as inherently unreliable, or accept it because of alternative misconceptions, for instance that such witnesses are incapable of lying. This chapter considers safeguards to ensure, as much as possible, the avoidance of convictions on unreliable evidence. The issues discussed include:
- the use of expert evidence to inform the jury of the intellectual disability of a witness or the accused, and how that disability impacts upon the giving and quality of evidence (an issue separate from fitness to be tried and criminal responsibility, which are dealt with in Chapters 4, 5 and 10); and
- whether any special measures, such as a warning by the judge, are required where the witness or accused has an intellectual disability.
EXPERT EVIDENCE ABOUT RELIABILITY
8.2 Intellectual disability does not necessarily render a person’s evidence unreliable. However, there are attributes of some people with an intellectual disability which may suggest unreliability to a finder of fact, whether judge or jury. For example, a witness or accused with an intellectual disability may:
- have limited communication skills, reduced attention span and memory recall; and/or
- be intimidated by the courtroom environment and by cross-examination, and so appear evasive, nervous, hesitant, or frustrated and angry.
A jury which is not informed about the effects intellectual disability may have on the giving and quality of evidence may view the evidence of a witness with an intellectual disability with unjustified scepticism. On the other hand, according to Hayes and Craddock, the person with an intellectual disability:
who performs badly in the witness box may be considered, erroneously, by the jury as too impaired to lie.1
This raises the question of whether evidence about intellectual disability, and how that disability affects the capacity of a witness, should be placed before the jury to disabuse them of any assumptions and preconceptions which may impair their capacity to weigh evidence objectively. Such evidence may be necessary even if the witness’ alleged unreliability has not been specifically raised by the other side.
8.3 The reliance on demeanour itself has been criticised:
[d]ecisions made by judges and juries are based in part on the manner and speech (“demeanour”) of parties and witnesses in legal proceedings. The enormous variation in communication styles, however, makes demeanour an unreliable basis for decision-making. It is a poor indicator of the honesty of the witness or the value of his or her evidence. ... At its most uncritical, reliance on demeanour condones pseudo-psychology, cultural ethnocentricism, gender bias and even racism as valid bases for decision-making.2
Such concerns have added weight when the witness has an intellectual disability. It has been argued that:
[a] party who calls an intellectually disabled witness may be concerned that, unless the jury is advised of the witness’ intellectual disability and its relevant consequences, his or her evidence may be inappropriately disregarded. For instance, the prosecution calling an intellectually disabled victim of a sexual assault, or the defence calling an intellectually disabled accused, may desire the jury to know the characteristics of the disability, in particular that unlike some mental illnesses, delusions are not a characteristic, so that the evidence is not unwittingly susceptible for that reason; or perhaps that the witness’ “nerves” should not unduly be mistaken for an indication of lying. In view of the general community ignorance of the nature of intellectual disability, this is a reasonable concern.3
8.4 Currently, however, apart from evidence of a very general nature, such as information on employment and marital status, a party may not lead evidence in chief to “bolster the credibility” of its own witness, because the law presumes that a party tenders a witness as capable of being believed.4 This rule was recently applied in England in circumstances relevant to this discussion.5 The Court held that the prosecution could not call a witness (in this case a girl aged 15 with an intellectual disability, who was also the alleged victim) and then, without more, call a psychologist or psychiatrist to give reasons why the jury should regard that witness as reliable. In that case the prosecution had sought to call evidence from an educational psychologist as to whether or not the girl was suggestible or likely to fantasise. Such evidence was seen as “oath-helping” and was therefore inadmissible. Thus evidence cannot generally be led to alert the jury to the existence, and effect on the witness’s demeanour, of an intellectual disability. This restriction is limited to evidence-in-chief: expert evidence may be led in some circumstances to counter a case put in cross-examination that a witness was unreliable.6
8.5 Evidence may be led to discredit another party’s witness, for instance to show that a witness is unreliable, to diminish the value of their evidence. Such evidence may relate to mental disorder:
[m]edical evidence is admissible to show that a witness suffers from some disease or defect or abnormality of mind that affects the reliability of his evidence. Such evidence is not confined to a general opinion of the unreliability of the witness, but may give all the matters necessary to show not only the foundation of and reasons for the diagnosis but also the extent to which the credibility of the witness is affected.7
It also seems clear that expert evidence may be led to challenge the reliability of a confession by an accused with an intellectual or other disability8 and that a judge may, in certain circumstances, warn the jury that to convict on the evidence of a witness with an intellectual disability may be dangerous (see paras 8.9-8.15). There is no corresponding opportunity, however, for the jury to be informed of matters relevant to the evidence of a witness with an intellectual disability, unless the credibility of that witness has been challenged in cross-examination.
8.6 The use of expert evidence to overcome such problems and to assist the court was suggested in various submissions to the Commission.9 The Redfern Legal Centre Intellectual Disability Rights Service, for example, pointed to the need for expert evidence to explain the particular abilities and limitations of a witness with an intellectual disability:
[t]his can go in some way to counter possible confusion and inadequacies in testimony which may be revealed in the course of the trial. Without such evidence, the witness may be perceived as unreliable or deceitful.10
The Kingsford Legal Centre also stated:
[w]e strongly support the use of evidence as to a disability in Court, or at any earlier time if it would then be useful. ... It is naive and inappropriate for judges and magistrates to consider that their life experience properly equips them to assess accurately the extent, effects, and implications of an intellectual disability.11
The Evidence Bill
8.7 The credibility of witnesses is referred to in Part 3.7 of the exposure draft of the Evidence Bill 1993 (NSW). Similar provisions are found in the Evidence Bill 1993 (Cth), which has already been introduced into the Commonwealth Parliament, but has not been passed.12 Evidence which is relevant only to a witness’ credibility is not admissible,13 except on cross-examination where the evidence has substantial probative value,14 and on re-examination in order to re-establish credibility damaged in cross-examination.15 The accused in a criminal trial who gives sworn evidence may be cross-examined on matters relevant solely to credibility with the leave of the court only, unless the evidence relates to bias, a motive to be untruthful, recollection, or prior inconsistent statements.16 Other exceptions relate to evidence given by one witness of another witness’ credibility, and to the credibility of the maker of a hearsay statement admitted under other provisions in the Bill.17 The Bill, if passed, will also abolish a number of rules relating to opinion evidence, including the “ultimate issue” rule (which prevents a witness from expressing an opinion on an issue to be decided by the court) and the “common knowledge” rule (which prohibits witnesses from giving evidence of opinion about matters of common knowledge).18 The Bill will not, however, overcome the difficulty in relation to evidence in chief about the witness’ intellectual disability discussed above.
The Commission’s proposal
8.8 The Commission proposes that a party should, with the leave of the court, be able to bring expert evidence about the intellectual disability of that party’s witness (including the accused where he or she gives evidence):
(a) where expert evidence is needed to clarify that witness’ manner of giving of evidence; and
(b) where expert evidence is needed to understand how the witness’ degree of disability is important to the circumstances of the offence or, if the witness is not the accused, to explain/provide evidence about the way the person behaved.
Such evidence may be necessary to satisfy the interests of justice by lessening the chance of the judge and jury being misled by the witness’ presentation in the witness box. The evidence should not be seen as simply suggesting to the jury that they should believe the witness, but rather as necessary evidence about the character/responses/behaviour of a special type of person. The normal requirements for giving expert evidence would still apply. The requirement that the court’s leave be first obtained should ensure that the provision is not used in inappropriate cases. The contrary argument is that it is inappropriate that matters which go to the credit of a witness be raised in evidence in chief, or be raised at all unless specifically put by the opposing party. It may also be argued that such issues affect every trial and that there should not be special rules for the witness with an intellectual disability. However, intellectual disability is clearly an area in which there is a general lack of knowledge and about which judges and juries therefore may lack understanding, and a court should receive assistance in its assessment of such a witness. It must be in the interests of justice that relevant matters about, for instance, the way a person’s disability affects his or her manner of giving evidence, are put before the court.
PROVISIONAL PROPOSALS FOR REFORM
31. A party in a criminal trial should be able, with the leave of the court, to call expert evidence in chief about a witness’s intellectual disability, where there is a risk that in the absence of that evidence the trier of fact (judge or jury) will be unable to give proper consideration to the reliability of the witness’ evidence. This evidence should be admitted to inform the trier of fact of the manner in which the intellectual disability may affect the cognitive, communication, and memory skills of the witness in relation to the giving of evidence, and to explain the behaviour of the person.
CORROBORATION AND OTHER JUDICIAL WARNINGS
Warnings about confessions
8.9 As discussed above, expert evidence is also likely to be relevant in considering the reliability of confessions by the accused with an intellectual disability. The treatment by the courts of confessions in general is a controversial issue, and merits a far more detailed study than is possible within the confines of this reference. However, the manner in which the law on confessions impacts upon people with an intellectual disability is important, particularly in relation to voluntariness, the discretions to exclude confessions and police conduct. Such issues were considered in the Policing Issues Discussion Paper. In that Paper the Commission also made a large number of proposals (for instance, in relation to the presence of a lawyer and support person, and Codes of Practice) to provide safeguards for the questioning of a suspect in police custody. It was proposed that evidence obtained in breach of those safeguards may lead to inadmissibility of the evidence. This Paper will not repeat that discussion, except for the area of judicial warnings about reliability.
8.10 A judge can give a warning to a jury in his or her summing up if there is doubt about the reliability of a confession.19 In McKinney20 the High Court set down a rule of practice that where the prosecution case rests solely or primarily upon a disputed confession allegedly made by an accused held in police custody, and the making of that confession is not corroborated by other reliable evidence, the judge must warn the jury of the danger of convicting. According to Ligertwood, the need for a warning in these circumstances was based not only on the possible unreliability of the confession, but also on the grounds of public policy, to encourage the use by police of electronic recording facilities in police questioning.21 The so-called “McKinney” warning provides a useful but limited protection for the accused, but does not overcome the difficulty where there is no allegation of police misconduct (and in fact the confession may have been electronically recorded in the presence of a lawyer) but the defence argues that the accused’s evidence may be unreliable, for example that the person is a compulsive confessor.
8.11 As discussed further below, where a witness (including the accused) has a “mental disability” which may affect his or her capacity to give reliable evidence, it has also been held that a trial judge should give a warning in summing up about the possible danger of basing a conviction on that testimony without confirmation by other evidence.22 Such a warning is not limited to confessions. The Policing Issues Discussion Paper proposed further that there should be a statutory provision requiring a warning to the jury on the danger of convicting on the basis of the confession of a person with an intellectual disability alone.23 With further consideration, and in light of submissions,24 the Commission has decided to revise its proposal (which effectively amounted to a mandatory corroboration warning), as such a proposal could imply that the evidence of any witness with an intellectual disability must be unreliable, which is not necessarily the case. The Commission therefore suggests that, apart from the existing special protections for the accused, the position for any witness (including the accused) should be the same. Thus a judge, if requested by a party to give a reliability warning, should give such a warning, unless he or she believes there are good reasons not to do so. Presumably evidence must be presented to suggest why the evidence may be unreliable. The terms of such a warning should be a matter for the judge. This proposal, set out at Proposal 32 below, substantially reflects the position in the exposure draft of the Evidence Bill 1993 (NSW).
Warnings for all witnesses
8.12 It has also been suggested that a mandatory or discretionary jury warning about the danger of convicting on uncorroborated evidence may also be appropriate for any witness with an intellectual disability (not just the accused), because of the possibility of unreliability. The appropriateness of a warning may depend upon the level of disability, expert evidence as to the effect of the disability on memory recall or suggestibility, and any other relevant matter.25
8.13 Some brief consideration of the rules relating to corroboration is necessary at this point. In general terms, corroboration is independent evidence which supports what a witness says about the facts in issue. The law of corroboration, however:
consists of a series of limited and technical rules that, in the main, govern the way in which judges must direct juries about certain specific categories of prosecution evidence.26
While the rules regarding what is or is not corroborative evidence are complex, in general:
it “confirms”, “supports” or strengthens” other evidence in the sense that it “renders [that] other evidence more probable” ... It must do that by connecting or tending to connect the accused with the crime charged ...27
At common law (except in perjury cases) the evidence of a single uncorroborated witness is sufficient to convict.28 Specific legislation has, however, required corroboration for some offences or for the evidence of various classes of witness, such as the unsworn evidence of children, or has required the judge to give a warning that it is unsafe to convict on the evidence of some classes of witness.
8.14 Apart from legislation, the common law also provided, in certain circumstances, for a warning to the jury against acting on possibly unreliable evidence where that evidence is uncorroborated. The jury is, however, left to decide how to act on the evidence; and so it is the warning, rather than corroboration, which is required.29 Although there is some disagreement as to which classes of witness require a warning, accomplices, children, and the victims of sexual assault have (at times) fallen into this category. Ligertwood suggests that in Australia it is doubtful whether the warning is now mandatory for any of these categories,30 though warnings are usually given. People with an intellectual disability or a mental illness have not been seen as an additional category of witness where there is a requirement to give a “full corroboration warning”.31 To a large degree the mandatory corroboration rules (whether statutory or common law) have been, or are in the process of being, removed, for instance see the provisions of the exposure draft of the Evidence Bill 1993 (NSW), discussed below.32
8.15 The courts, however, also have a “general discretion to warn which has developed outside corroboration law”,33 “which arises whenever there is a danger of convicting on potentially unreliable evidence.”34 Ligertwood refers to this as a “residual category of unreliable witnesses”.35 The most relevant case for the evidence of witnesses with an intellectual disability or mental illness in Australia in this area is Bromley, where a majority of the High Court considered the general requirement for a judge to warn about unreliable evidence and stated:
If it appears that a witness whose evidence is important has some mental disability which may affect his or her capacity to give reliable evidence, common sense clearly dictates that the jury should be given a warning, appropriate to the circumstances of the case, of the possible danger of basing a conviction on the testimony of that witness unless it is confirmed by other evidence. ... There is no particular formula that must be used; the words used must depend on the circumstances of the case.36
This case has been cited in a number of recent New South Wales Court of Criminal Appeal judgments.37 Concerns still remain about the appropriateness and effectiveness of judicial warnings, rather than the exclusion of unreliable evidence.38
The Evidence Bill
8.16 The exposure draft of the Evidence Bill 1993 (NSW) and the Evidence Bill 1993 (Cth) abolish corroboration requirements, except for the offence of perjury or a similar or related offence; and provide that the giving of a judicial warnings on the danger of acting on uncorroborated evidence, and judicial directions relating to the absence of corroboration, are discretionary.39 In relation to warnings about unreliable evidence (which is not necessarily uncorroborated evidence), they provide that when requested by a party, the judge is obliged, unless there are good reasons for not doing so, to:
The judge also may give a warning or direction to the jury at his or her own discretion.41 (See Appendix C for the full text of the New South Wales provisions.)
8.17 Both Bills set out the categories of evidence to which the section applies: that is, evidence “of a kind which may be unreliable”.42 No distinction is drawn between the evidence of an accused and that of any other witness. One of these categories is “evidence the reliability of which may be affected by age, ill health (whether physical or mental), injury or the like”.43 It could be argued that, since intellectual disability is not an illness, nor “like” an illness, the warning provisions within the respective Bills do not apply to evidence of witnesses with an intellectual disability.
8.18 The Commission suggests that “intellectual disability” should be specifically referred to as a possible category of unreliability, to avoid confusion in this area. The danger of such an inclusion is that though there is nothing inherently unreliable about evidence given by witnesses with an intellectual disability, to include their evidence on the list of that which “may be unreliable” would appear to assume that this is the case. However, the clause does not purport to be exhaustive and it does not otherwise extend or diminish the existing judicial discretion to warn or direct in appropriate cases. Thus the Commission does not propose a mandatory warning about convictions based on the uncorroborated evidence of a witness with an intellectual disability, but rather proposes that cl 164 of the Evidence Bill 1993 (NSW) which provides a general discretion to warn where evidence may be unreliable (whether or not it is corroborated) be amended to specifically include a reference to intellectual disability. Again, expert evidence and judicial awareness of intellectual disability issues will be important in this area.
PROVISIONAL PROPOSALS FOR REFORM
32. That cl 164 of the Evidence Bill 1993 (NSW) be amended to provide that the evidence of people with an intellectual disability is a category of evidence which may be unreliable, and which may attract a judicial warning upon the judge being requested by a party to give such a warning to the jury.
FOOTNOTES
1. S C Hayes and G Craddock Simply Criminal (2nd ed, Federation Press, Sydney, 1992) at 183.
2. K Laster and V L Taylor Interpreters and the Legal System (Federation Press, Sydney, 1994) at 162 [footnote references omitted]. See also M Frank “Assessing deception”, paper presented at the conference Psychology and the Legal Process (University of Sydney, 29 March 1994).
3. M Ierace Intellectual Disability: A Manual for Criminal Lawyers (Redfern Legal Centre Publishing, Sydney, 1989) at 118.
4. R v Turner [1975] 1 All ER 70 at 75, distinguishing Lowery v R [1973] 3 All ER 662 on its facts; D Byrne and J D Heydon (eds) Cross on Evidence (Loose leaf edition, Butterworths, Sydney) (“Cross”) at para 19005.
5. R v Robinson [1993] TLR 595.
6. Cross at para 19175.
7. Toohey v Metropolitan Police Commissioner [1965] 1 All ER 506 at 512, per Lord Pearce.
8. Murphy v R (1989) 167 CLR 94. See also the English cases of R v Ragship (unreported, 5 December 1991) and R v Ward [1993] 2 All ER 577 cited in R v Robinson [1993] TLR 595.
9. New South Wales Sexual Assault Committee Submission (August 1992) at 5; The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 10; Australia. Attorney-General’s Department, Office of Legal Aid and Family Services Submission (28 August 1992) at 4; Kingsford Legal Centre Submission (29 October 1992) at 4-5; Confidential Submission (4 September 1992) at 29-35; and Redfern Legal Centre Intellectual Disability Rights Service Submission (6 January 1992) at 6.
10. Redfern Legal Centre Intellectual Disability Rights Service Submission (6 January 1992) at 6.
11. Kingsford Legal Centre Submission (29 October 1992) at 4-5.
12. The background to the Evidence Bills was discussed in para 7.11.
13. Evidence Bill 1993 (NSW) cl 102; Evidence Bill 1993 (Cth) cl 102.
14. Evidence Bill 1993 (NSW) cl 103; Evidence Bill 1993 (Cth) cl 103.
15. Evidence Bill 1993 (NSW) cl 107; Evidence Bill 1993 (Cth) cl 108.
16. Evidence Bill 1993 (NSW) cl 104; Evidence Bill 1993 (Cth) cl 104.
17. Evidence Bill 1993 (NSW) cl 105, 106; Evidence Bill 1993 (Cth) cl 106, 107.
18. Evidence Bill 1993 (NSW) cl 79; Evidence Bill 1993 (Cth) cl 80.
19. See also J Hunter “Unreliable memoirs and the accused: Bending and stretching hearsay - Part One” (1994) 18 Criminal Law Journal 8 at 22-26.
20. McKinney v R (1991) 171 CLR 468.
21. A Ligertwood Australian Evidence (2nd ed, Butterworths, Sydney, 1993) at para 4.12.
22. Bromley v R (1986) 161 CLR 315. In R v Parker the New South Wales Court of Criminal Appeal summarised the principles relevant to the treatment of confessions by people with an intellectual disability, and referred to the possible need for a Bromley warning: (1990) 19 NSWLR 177 at 183-184, per Gleeson CJ.
23. New South Wales. Law Reform Commission People with an Intellectual Disability in the Criminal Justice System: Policing Issues (Discussion Paper 29, 1993) Proposal 29.
24. For example the New South Wales Bar Association Submission (12 January 1994) at 5; and Office of the Director of Public Prosecutions, New South Wales Submission (7 February 1994) at 1-2.
25. Ierace at 110.
26. England and Wales. The Law Commission Corroboration of Evidence in Criminal Trials (Report 202, 1991) at 1.
27. Doney v R (1990) 171 CLR 207 at 211 [references omitted].
28. Cross at paras 15001, 15010.
29. Ligertwood at para 4.03.
30. Ligertwood at para 4.11.
31. In the English cases of R v Spencer and R v Smails the prosecution witnesses were psychiatric patients who had been convicted of serious offences. On appeal, the House of Lords said that where the evidence for the Crown is solely that of a witness who is not in one of the accepted categories of witnesses for whom a “full warning” as to the necessity of corroboration is required (that is, accomplices, children giving evidence under oath and the alleged victims of sexual assault), but who, by reason of his particular mental condition and criminal connection, fulfilled “analogous criteria”, the judge must warn the jury that it is dangerous to convict on his uncorroborated evidence: [1987] AC 128 at 142. The use of the words “danger” or “dangerous”, however, was not an essential part of the warning: at 146. Spencer was considered in Bromley v R (1986) 161 CLR 315.
32. In New South Wales, there is no longer a requirement (although there is a discretion) to warn that it is unsafe to convict on the uncorroborated evidence of a child, whether the evidence is given on oath or otherwise: Evidence Act 1898 (NSW) s 42A. New South Wales has also abolished mandatory warnings about the evidence of victims of sexual assault: Crimes Act 1900 (NSW) s 405C.
33. Hunter at 23, citing Bromley v R (1986) 161 CLR 315 and Longman v R (1989) 168 CLR 79. Hunter states, at 24, that a judicial warning is clearly required in three specific circumstances: identification evidence; McKinney confessions and prison informers.
34. Hunter at 25.
35. Ligertwood at para 4.36.
36. Bromley v R (1986) 161 CLR 315 at 319 per Gibbs CJ. (Compare the minority judgment of Brennan J.)
37. See, for example R v Clough (1992) 28 NSWLR 396 at 404-405, per Hunt CJ at CL; R v Halls (unreported) Supreme Court, NSW, Court of Criminal Appeal, 1 September 1993, CCA 60386/92, per Grove J at 3-4 (Gleeson C J and Sully J concurring).
38. Hunter at 25-26.
39. Evidence Bill 1993 (NSW) cl 163; Evidence Bill 1993 (Cth) cl 164.
40. Evidence Bill 1993 (NSW) cl 164(2), (3); Evidence Bill 1993 (Cth) cl 165(3), (4).
41. Evidence Bill 1993 (NSW) cl 164(5); Evidence Bill 1993 (Cth) cl 165(6).
42. Evidence Bill 1993 (NSW) cl 164(1); Evidence Bill 1993 (Cth) cl 165(1).
43. Evidence Bill 1993 (NSW) cl 164(1)(c); Evidence Bill 1993 (Cth) cl 165(1)(c).
