[1] The question of who is an expert is a matter for the trial judge to decide. The proposed witness must have specialised skill or knowledge through study, training or experience such as to render him or her an expert in a particular area or field of study (though this knowledge need not have been acquired professionally: R v Silverlock [1894] 2 QB 766, in which a solicitor who had studied handwriting for ten years, mostly as an amateur, was treated as an expert). As well, the proposed field of expertise must be sufficiently well-established to pass the ordinary tests of relevance and reliability. If these are met, then the expert evidence can be admitted and its assessment is left to the finder of fact as a question of weight. See, for instance, Bingham LJ's comments in R v Robb (1991) 93 Cr. App. 161 at 164-165:
The old-established, academically-based sciences such as medicine, geology or metallurgy, and the established professions such as architecture, quantity surveying or engineering, present no problem. The field will be regarded as one in which expertise may exist and any properly qualified member will be accepted without question as an expert. Expert evidence is not, however, limited to these core areas. Expert evidence of fingerprints, handwriting and accident reconstruction is regularly given. Opinions may be given of the market value of land, ships, pictures or rights. Expert opinions may be given of the quality of commodities, or on the literary, artistic, scientific or other merit of works alleged to be obscene...Some of these fields are far removed from anything which could be called a formal scientific discipline. Yet while receiving this evidence the courts would not accept the evidence of an astrologer, a soothsayer, a witch-doctor or an amateur psychologist...[T]he essential questions are whether study and experience will give a witness's opinion an authority which the opinion of one not so qualified will lack, and (if so) whether the witness is [skilled and has the requisite knowledge]...If these conditions are met the evidence of the witness is in law admissible, although the weight to be attached to his opinion must of course be assessed by the tribunal of fact.
[2] J Acker has defined "social science research evidence" as information derived from the traditional methods of science - through systematic observation and objective measurement, allowing for replication and empirical verification - and within the subject purview of the social sciences, the study of behavioural events relevant to individuals and social relations, including psychology, sociology, psychiatry, economics, political science and criminal justice, but not history. J Acker "Thirty Years of Social Science in Supreme Court Criminal Cases" (1990) 12 Law & Policy 1 at 4.
[3] Buckley v Rice-Thomas (1554) 1 Plowd 118 at 124.
[4] Per Lawton LJ in R v Turner [1975] QB 834 at 841, cited with approval by Lord Wilberforce in DPP v Jordan [1977] ADC 699 at 718. See also, generally, I Dennis The Law of Evidence (London: Sweet & Maxwell, 1999) at pp 654 - 673, A Keane The Modern Law of Evidence (4th edition) (London: Butterworths, 1996) pp 453 - 475 and C Tapper Cross and Tapper on Evidence (8th edition) (London: Butterworths, 1995) pp 543 - 562. For a discussion of this particular aspect of the use and limits of expert evidence in an Australian context, see, for example, Farrell v The Queen [1998] HCA 50 at paragraphs 29 and 91 - 95.
[5] The term "battered woman syndrome" is used to describe a pattern of physical and psychological abuse inflicted upon a woman by her husband or partner. A battered woman is defined as [a] woman who is repeatedly subjected to any forceful physical or psychological behavior by a man in order to coerce her to do something he wants her to do without any concern for her rights. Battered women include wives or women in any form of intimate relationships with men. Furthermore, in order to be classified as a battered woman, the couple must go through the battering cycle at least twice. Any woman may find herself in an abusive relationship with a man once. If it occurs a second time, and she remains in the situation, she is defined as a battered woman. L Walker The Battered Woman (New York: Harper and Row, 1979) at xv. Battered woman syndrome has been critiqued as syndromising and psychologising women and for its emphasis on 'learned helplessness', which is the idea that abused women develop a deficiency in perceiving exit when it is actually available. As Katherine O'Donovan has observed, "the idea of 'learned helplessness'...does not fully explain how the accused comes to act, with fatal results for the abuser": K O'Donovan "Law's Knowledge: The Judge, The Expert, The Battered Woman and Her Syndrome" (1993) 20 Journal of Law and Society 427 at 431. A further critique of the "syndrome" and "victim label" is that it implies that it is the women's reaction to the violence visited upon them and not the violence itself that is the problem, and that it does not reflect the complexity of the women's own experience nor their own resilience in the face of that violence: M Mahoney "Legal Images" (1991) 90 Michigan Law Review 1 at 15. See also E Sheehy, J Stubbs and J Tolmie "Defending Battered Women on Trial: The Battered Women Syndrome and its Limitations" (1992) 16 Criminal Law Journal 369 and C Wells "Battered Woman syndrome and defences to homicide: where now?" (1994) 14 Legal Studies 266.
[6] The term "domestic violence" as it is used here refers to physical violence and emotional, psychological and sexual abuse of women in the home by their (usually male) partners. The physical abuse ranges across slaps, pushes and punches to stabbing and shooting. This term also accommodates abuse of women by their partners outside the home - violence, shouting and threatening in a public place, for instance. This term thus encompasses abuse wherever it is experienced. Domestic violence is not restricted to heterosexual partners and can be experienced by gay male or lesbian partners, and can be violence against men by female partners. However, the preponderance of victims of domestic violence are women: C Hemmens, K Strom & E Schlegel "Gender Bias in the Courts: A Review of the Literature" (1998) 35 (1) Sociological Imagination 22 at 24, where they state: Ninety-eight percent of domestic violence victims are women. Nationwide, 28% of female homicide victims are killed by former husbands or boyfriends, whereas only 5% of male homicide victims are killed by former wives of girlfriends. Domestic violence is the number one cause of physical injury to women in the United States (citations omitted). See also M Tuck Domestic Violence: Report of a National Inter-agency Working Party (London: Victim Support, 1994), L Smith Domestic Violence: An Overview of the Literature (London: Home Office Research and Planning Unit, 1989). Domestic violence is also about the gendered nature of power: who has it, who exercises it, and upon whom is it exercised. Traditionally, the official criminal justice agencies of law enforcement and courts were reluctant to intervene in what was considered a couple's - and more particularly the man's - private life, thus maintaining a strict separation of the public and private spheres of a person's life. For accounts of the history of domestic violence, see, generally, M Fineman & R Mykitiuk (eds.) The Public Nature of Private Violence: The Discovery of Domestic Abuse (New York: Routledge, 1994), R Dobash and R Dobash Violence Against Wives: A Case Against the Patriarchy (New York: Free Press, 1979) and W DeKeseredy & R Hinch Woman Abuse: Sociological Perspectives (Toronto: Thompson Educational Publishing Inc, 1991).
[7] See, for example, K Rodgers "Wife Assault: The Findings of a National Survey" (1994) 14 (9: March) Juristat Service Bulletin, Ottawa, Canadian Centre for Justice Statistics, M Fineman & R Mykitiuk (eds.) above note 6, I Arias, D Dwyer "Response to the Victims of Domestic Violence: Analysis and Implications of the British Experience" (1995) October Crime and Delinquency 527, R Davis & B Smith "Domestic Violence Reforms: Empty Promises or Fulfilled Expectations?" (1995) 41 (4) Crime & Delinquency 541, M Samios & K O'Leary "Prevalence and correlates of physical aggression during courtship" (1987) 2 Journal of Interpersonal Violence 82, L Stalans & A Lurigio "Public Preferences for the Court's Handling of Domestic Violence Situations" (1995) 41 (4) Crime & Delinquency 399 and J Hanmer, S Griffiths & D Jerwood "Arresting Evidence: Domestic Violence and Repeat Victimisation" (London: Home Office Research, Development and Statistics Directorate, 1999).
[8] M Donnelly "Battered Women who kill and the Criminal Law Defences" (1993) 3 (2) Irish Criminal Law Journal 161, K O'Donovan "Defences for Battered Women Who Kill" (1991) 18 Journal of Law and Society 219, D Nicolson & R Sanghvi "Battered Women and Provocation: The Implications of R v Ahluwalia" [1993] Criminal Law Review 728, W Chan "A Feminist Critique of Self-Defense and Provocation in Battered Women's Cases in England and Wales" (1994) 6 (1) Women & Criminal Justice 39 and C Wells "Battered Woman syndrome and defences to homicide: where now?" above note 5.
[9] For example, see J McKendry "The Class Politics of Domestic Violence" (1997) 24 (3) Journal of Sociology and Social Welfare 135, J Stubbs & J Tolmie "Race, Gender and the Battered Woman Syndrome" (1995) 8 Canadian Journal of Women and the Law 122, E Lupri, E Grandin & M Brinkerhoff " Socioeconomic status and male violence in the Canadian home: a reexamination" (1994) 19 Canadian Journal of Sociology 47, J Krane "Violence Against Women in Intimate Relations: Insights from Cross Cultural Analyses" (1996) 33 Transcultural Psychiatric Research Review 435, J Cribb & R Barnett "Being Bashed: Western Samoan Women's Response to Domestic Violence in Western Samoa and New Zealand" (1999) 6 (1) Gender, Place and Culture 49 and D Counts, J Brown & J Campbell (eds.) Sanctions and Sanctuary: cultural perspectives on the beating of wives (Boulder: Westview Press, 1992).
[10] See, for instance, E Sheehy, J Stubbs & J Tolmie above note 5, C Wells "Battered Woman syndrome and defences to homicide: where now?" above note 5, P Easteal "Battered Woman Syndrome Misunderstood" (1992) 3 Issues in Criminal Justice 356, D Faigman "The Battered Woman Syndrome and Self-Defence: A Legal and Empirical Dissent" (1986) 72 Virginia Law Review 619, D Martinson, M MacCrimmon, I Grant & C Boyle "A Forum on Lavallee v R: Women and Self-Defence" (1991) 25 UBC Law Review 23, I Leader-Elliot "Battered but not Beaten: Women who Kill in Self-Defence" (1993) 15 Sydney Law Review 403, D Nicolson & R Sanghvi "Battered Women and Provocation: The Implications of R v Ahluwalia" above note 8, M Griffith "Battered Woman Syndrome: A Tool for Batterers?" (1995) 64 Fordham Law Review 141 and A Blowers and B Bjerregaard "The Admissibility of Expert Testimony on the Battered Woman Syndrome in Homicide Cases" (1994) 22 Journal of Psychiatry & Law 527.
[11] Homicide Act 1957, s. 3: Where on a charge of murder there is evidence on which the jury can find that the person charged was provoked (whether by things done or things said or by both together ) to lose his [sic] self-control, the question whether the provocation was enough to make a reasonable man [sic] do as he did shall be left to be determined by the jury; and in determining that question the jury shall take into account everything done and said according to the effect which, in their opinion, it would have on a reasonable man.
[12] Homicide Act 1957, s. 2: Where a person kills or is party to the killing of another, he [sic] shall not be convicted of murder if he was suffering from such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his mental responsibility for his acts and omissions in doing or being a party to the killing.
[13] Self-defence is a common law justification, rather than a defence in strict terms, that has the effect of negativing an element of the offence so as to render it lawful. It overlaps with s. 3 of the Criminal Law Act 1967, which provides: (1) A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large. (2) Subsection (1) above shall replace the rules of common law on the question when force used for a purpose mentioned in the subsection is justified by that purpose. For arguments that self-defence more adequately reflects the facts and circumstances under which battered women kill their abusive partners, see A McColgan "In Defence of Battered Women who Kill" (1993)
[13] Oxford Journal of Legal Studies 508 and C Wells "Battered Woman syndrome and defences to homicide: where now?" above note 5.
[14] A classic self-defence scenario involves two men in a bar room brawl, a situation in which the danger is imminent, the attack is underway and the two combatants do not have a history of violence with each other. This scenario is laden with generalisations that may be entirely inappropriate to women in battering situations: He stands and faces his adversary, meeting fists with fists. He isn't frightened or provoked to violence by mere threats; he doesn't use a weapon unless one is being used against him; and he doesn't indulge himself in cowardly behaviour such as lying in ambush or sneaking up on an enemy unawares. C Gillespie Justifiable Homicide: Battered Women, Self-Defense and the Law (Columbus: Ohio State University Press, 1989) at 99.
[15] R. v Duffy [1949] 1 All ER 932 at 932.
[16] Ibid.
[17] Ibid.
[18] R v Thornton [1992] 1 All ER 306.
[19] Ibid. at 314.
[20] Ibid. at 313 - 314.
[21] R v Ahluwalia [1992] 4 All ER 889.
[22] Taylor LJ stated that
We accept that the subjective element in the defence of provocation would not as a matter of law be negatived simply because of the delayed reaction in such cases, provided that there was at the time of the killing 'a sudden and temporary loss of self-control' caused by the alleged provocation. However, the longer the delay and the stronger the evidence of deliberation on the part of the defendant, the more likely it will be that the prosecution will negative provocation. Ibid. at 896.
[23] R v Dix (1981) 74 Cr App R 306.
[24] Gillespie above note 14 and K O'Donovan "Law's Knowledge: The Judge, The Expert, The Battered Woman and Her Syndrome" above note 5 at 428 - 429. The inability of the reasonable man paradigm to accommodate battered women is nicely set out in Madam Justice Wilson's reasons for judgment in R v Lavallee [1990] 1 SCR 852. This landmark Canadian case admitted expert evidence of battered woman syndrome to support a plea of self-defence to murder where a woman had killed her abusive partner. Wilson J wrote: If it strains credulity to imagine what the 'ordinary man' would do in the position of a battered spouse, it is probably because men do not typically find themselves in that situation. Some women do, however. The definition of what is reasonable must be adapted to circumstances which are, by and large, foreign to the world inhabited by the hypothetical 'reasonable man'. R v Lavallee ibid. at 874. For additional analysis of Justice Wilson's commentary on this point, see M MacCrimmon "A Forum on Lavallee v R: Women and Self-Defence" above note 10 at 42.
[25] State v Kelly 478 A 2d 364 (1984) at 378. On the problematising of the "common" in "common sense", see M MacCrimmon "Developments in the Law of Evidence" (1990) 2 Supreme Court Law Review (2d) 385 at 386, where she says that the law of evidence assumes that "understanding human behaviour is merely a matter of common sense." Common based upon whose reality and knowledge? See also A Worral, who suggests that "common" sense is "'common' because it is presumed to be simple, consensual and universally applicable" and "'sense' because its truth can supposedly be grasped or 'sensed' without being articulated or rationally justified": Offending Women: Female Lawbreakers in the Criminal Justice System (London: Routledge, 1990) at 18.
[26] This point is raised in several of the analyses of the "battered woman syndrome" defence cited in notes 5 and 10 above. See also I Grant "The 'Syndromization' of Women's Experience" in "A Forum on Lavallee v R: Women and Self-Defence" above note 10 at 51.
[27] I Newton Philosophić Naturalis Principia Mathematica (Londini: Jussu Societatis Regić ac Typis Josephi Streater, 1687).
[28] For a fuller analysis of this "flight to objectivity", see S Bardo The Flight to Objectivity: Essays on Cartesiansim and Culture (Albany: State University of New York Press, 1987).
[29] T Ward "Law, Common Sense and the Authority of Science: Expert Witnesses and Criminal Insanity in England, ca. 1840 - 1940" (1997) 6 (3) Social and Legal Studies 343 at 345.
[30] Ibid. at 348. See also M Valverde "Social Facticity and the Law: A Social Expert's Eyewitness Account of Law" (1996) 5 (2) Social and Legal Studies 201 at 204 - 205.
[31] "Scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified": M Green "Expert Witnesses and sufficiency of evidence in toxic substances litigation: The legacy of Agent Orange and Bendectin litigation" (1992) 86 NW U L Rev 643 At 645. See also C Hempel Philosophy of Natural Science (Englewood Cliffs: Prentice-Hall, 1966) at 49: "statements constituting a scientific explanation must be capable of empirical test" and K Popper Conjectures and Refutations: The Growth of Scientific Knowledge (5th ed.) (London: Routledge, 1989) at 37: "the criterion of the scientific status of a theory is its falsibility, or refutability, or testability".
[32] The fragmented aspect of the sciences is readily seen in the range and variety of expert witnesses on offer to practising lawyers. As a member of the British Columbia bar, I frequently receive mass mailings advertising the services of experts in a bewildering array of scientific fields. See also C Pamplin (ed.) UK Register of Expert Witnesses (5th ed.) (Chorley: JS Publications, 1992) , which covers over 800 different subjects. See also S Golding "Mental Health Professionals and the Courts: The Ethics of Expertise" (1990) 13 International Journal of Law and Psychiatry 281 at 281, where he states that "[w]hile the forensic mental health profession is a specialty, it is a mistake not to acknowledge the diversity of particular roles and to recognize that expertise within the specialty does not translate to expertise across the domain of roles."
[33] S Janoff "What judges should know about the sociology of science" (1993) 77 Judicature 77 at 80.
[34] Ibid. at 77 - 78. See also B Latour & S Woolgar Laboratory Life: The Construction of Scientific Facts (2nd ed.) Princeton: Princeton University Press, 1986).
[35] D Kaye "Bible Reading: DNA Evidence in Arizona (1997) 28 (4) Arizona State Law Journal 1035 at 1035.
[36] The basis for DNA testing is the well-accepted proposition that, except for identical twins, each person has a unique overall genetic code. Because of limitations in the available technology, testing can only be performed on very limited segments of the entire DNA sequence. Since 99.9% of the DNA sequence in any two people is identical, accurate analysis is vital to determine whether there is a match of the remaining 0.1% of the DNA sequence of the sample compared.
[37] For a general review of some of the difficulties in interpreting data generated from DNA testing, see D Kaye "DNA Evidence: Probability, Population Genetics, and the Courts" (1993) 7 Harvard Journal of Law and Technology 101, A Jeffreys et al "Individual-Specific 'Fingerprints' of Human DNA" (1985) 316 Nature 76, B Devlin & N Risch "Ethnic Differentiation at VNTR Loci, with Specific Reference to Forensic Applications" (1992) 51 Am. J Human Genetics 534, and N Risch & B Devlin "On the Probability of Matching DNA Fingerprints" (1992) 255 Science 717.
[38] For the test for appropriate expertise, see note 1 above.
[39] A working definition of relevance is provided in DPP v Kilbourne [1973] AC 729 at 756: "Evidence is relevant if it is logically probative or disprobative of some matter which requires proof...evidence which makes the matter which requires proof more or less probable."
[40] See, for example, Sherrard v Jacob [1965] NI 151 at 157 - 158 CA.
[41] For example, a witness may testify that she saw a defendant with some property [the fact of possession], but may not testify that she thought the defendant was dishonest [the inference of theft].
[42] M Valverde "Social Facticity and the Law" above note 30 at 213.
[43] S Gothard "Rules of Testimony and Evidence for Social Workers Who Appear as Expert Witnesses in Courts of Law" (1989) 3 (3) Journal of Independent Social Work 7 at 9.
[44] Anxiety over appearance is not limited to witnesses. At the law firm at which I worked we regularly counselled our clients about "appropriate" attire for their appearance in court (usually as defendants), and as an articled student who made court appearances almost every day I knew better than to show up to court looking scruffy. There were some wonderful stories - possibly apocryphal - about the court exercising its power over articled students and junior lawyers by refusing to hear them on the basis that they were not "properly attired". One story involved a notoriously difficult judge who declined to hear a lawyer's application in chambers because the lawyer was wearing brown shoes rather than (the apparently) regulation black.
[45] This rule has been abolished in civil cases. Its abandonment was recommended by the Law Reform Committee's 17th Report and implemented by Section 3 (1) of the Civil Evidence Act 1972. This states that subject to any rules of court made in pursuance of 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 on shall be admissible in evidence. Section 3 (3) reads: "In this section 'relevant matter' includes an issue in the proceedings in question."
[46] How much longer criminal cases are to be under this embargo remains to be seen. The Criminal Law Revision Committee has recommended its abandonment (CI 43 of the draft bill annexed to its 11th report [Cmnd 4491]), but this has yet to be implemented. The ultimate issue rule has been officially abolished elsewhere. See, for example, Australia: section 80 of the Evidence Acts 1995 (NSW, Cth) states that Evidence of an opinion is not inadmissible only because it is about: (a) a fact in issue or an ultimate issue; or (b) a matter of common knowledge.
[47] A Keane The Modern Law of Evidence (4th ed.) above note 4 at 464.
[48] See, for instance, the Law Reform Committee 'Evidence of Opinion and Expert Evidence', Cmnd 4889, paras 266 - 271 cited in Cross & Tapper on Evidence above note 4 at 553 and R Jackson "The Ultimate Issue Rule: One Rule Too Many" [1984] Criminal Law Review 75.
[49] Expert witnesses theoretically have unique roles and responsibilities that they bring with them to the court. According to Creswell J,
1. Expert evidence presented to the court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content by the exigencies of the litigation... 2. An expert witness should provide independent assistance to the Court by way of objective unbiased opinion in relation to matters within his expertise... An expert witness in the High Court should never assume the role of an advocate. 3. An expert witness should state the facts or assumption upon which his opinion is based. He should not omit to consider material facts which could detract from his...concluded opinion... 4. An expert witness should make it clear when a particular question or issue falls outside his expertise... 6. If, after exchange of reports, an expert witness changes his view on a material matter having read the other side's expert's report or for any other reason, such change of view should be communicated (through legal representatives) to the other side without delay and when appropriate to the Court. National Justice Cia Naviera SA v Prudential Assurance Co Ltd, The Ikarian Reefer [1993] 2 LI Rep 58 at 81 - 82.
Thus the expert witness owes a duty as an officer of the court to assist the court quite above any duty owed to the client who is undoubtedly paying for the expert to appear on his or her behalf. While in theory this may be true, the reality of litigation suggests otherwise. Because of the adversarial nature of litigation, each side wages a battle for their version of "the truth", the idea being that "the truth" will emerge when each side has had an opportunity to present their evidence and test the validity of that of the other side. Each side of any litigation issue selects their own witnesses, and are hardly likely to select experts who will not support their version of the evidence. See also S Golding "Mental Health Professionals and the Courts: The Ethics of Expertise" above note 32 for a discussion of the ethical principles which should govern the offering of mental health professionals' expertise in the American criminal justice system.
[50] In the Law Reform Committee's 17th Report above note 45, the Criminal Law Revision Committee was of the view that the rule 'probably no longer existed': para 268. See also Lord Taylor CJ in R v Stockwell (1993) 97 Cr App Rep 260 at 265: the rule has become "a matter of form rather than substance."
[51] DPP v A & B C Chewing Gum Ltd. [1968] 1 QB 159 at 164, DC.
[52] R v Turner [1975] QB 834 at 841.
[53] R Underwager & H Wakefield "A Paradigm Shift for Expert Witnesses" (1993) 5 (3) Issues in Child Abuse Accusations 156 at 156.
[54] See also R Sarkowicz "Levels of Interpretation of a Legal Text" (1995) 8 (1) Ratio Juris 104, especially at 108 - 110.
[55] O Fiss "Objectivity and Interpretation" (1982) 34 Stanford Law Review 739 at 744.
[56] M Van Hoecke "The Use of Unwritten Legal Principles by Courts" (1995) 8 (3) Ratio Juris 248 at 251. See also R Sarkowicz "Levels of Interpretation of a Legal Text" above note 54.
[57] O Fiss "Objectivity and Interpretation" above note 55 at 745.
[58] Canada (Attorney General ) v Mossop [1991] 1 FC 18 at 35.
[59] This is a misnomer. This cases is often referred to as the Rodney King trial despite the fact that the defendants (Timothy Wind, Theodore Bresenio, Laurence Powell and Stacey Koon) were four Los Angeles police officers charged with the use of excessive force against motorist Rodney King.
[60] C Renoe "Seeing is Believing?: Expert Testimony and the Construction of Interpretive Authority in an American Trial" [1996] IX (no. 26) International Journal for the Semiotics of Law 115 at 122.
[61] Ibid. at 122 - 123.
[62] The jury, as finder of fact, preferred this interpretation of the facts: the officers were acquitted of the charge of using excessive force against Rodney King. In a subsequent trial, two of the four officers were convicted of violating Mr King's civil rights.
[63] N K Sam Banks "Knodel v British Columbia [Medical Services Commission]" (1993) 11 Canadian Journal of Family Law 287 at 297. For another view of this point, see D Herman "Are We Family? Lesbian Rights and Women's Liberation" (1989) 28 Osgoode Hall Law Journal 789.
[64] Valverde refers to "law's narcissistic deliberations" and "Law as Narcissus" above note 30 at 204 and 207, respectively.