By Professor Alfred Allan FAPS, School of Psychology and Social Science, Edith Cowan University and Dr Michael Davis MAPS, Centre for Forensic Behavioural Science, Monash University and Forensicare

Alfred Allan is the immediate past National Chair and Michael Davis is the National Secretary of the APS College of Forensic Psychologists.

Psychologists are often required to act as witnesses in courts and tribunals, a task requiring specialist knowledge, skills and judgement that is frequently underestimated. Any person who can contribute factual information to assist a court or tribunal to decide a legal issue can be compelled to testify as a witness of fact. Strictly speaking no witness is entitled to express opinions as the forming of opinions is the function of the court. However, there are occasions where courts lack the knowledge to form an opinion and will look to expert witnesses for guidance. The weight given to the opinions of these expert witnesses is determined on a case by case basis by the courts with reference to all the facts and opinions available to them.

Courts also allow psychologists to testify as witnesses of fact about clients they have treated and even permit them to express opinions, but limit these to the diagnosis and treatment of their clients. The weight given to the testimony of these treatment experts is often limited. Courts understand that treatment experts are not necessarily specialists in mental health or the specific issue on which they express an opinion. Courts also take the view that it is difficult or even impossible for people who have a prior relationship with a party, such as a therapeutic relationship, to be objective witnesses.

These complexities add to the variety of legal and ethical issues for psychologists who undertake court work. This article touches briefly on the history of psychologists providing evidence in courts, explores the ethical challenges and potential sources of bias in forensic psychology practice, and identifies guiding principles for psychologists who provide services in this specialist field.

Psychologists as experts in the courts

From the beginning of modern psychology in Europe, courts have permitted experimental psychologists to express opinions as expert witnesses (Davis, 2008a). Schrenk-Notzing, a pupil of Wundt, was the first psychologist known to have testified in court when he gave evidence about the credibility of witness testimony in a Munich murder trial in 1896. Marbe, another student of Wundt, was probably the first psychologist to have given evidence in a civil case in 1911 where it was alleged that an engine driver had caused a railway accident by failing to bring his train to a halt in time (Weijers, 2004). His demonstration of the phenomenon of reaction time was used by the court in finding that it would have been physically impossible for the engine driver to have stopped in time to prevent the accident (Haward, 1981).

Beyond allowing treatment experts to express opinions about the mental health of their clients, courts have been reluctant to allow psychologists to express opinions as expert witnesses on issues such as whether a person is suffering from posttraumatic stress disorder. The breakthrough for psychologists in this regard came when the Supreme Court of the United States held by a small majority in Jenkins v US (1962) that a clinical psychologist who was an expert in mental health could give an opinion on the presence or absence of mental disorders in court. From that time onwards, psychologists who are experts in the field have been increasingly allowed to express opinions about mental health issues and there has been a marked increase in the use of psychologists in courts. The courts decide whether an individual has enough expertise to express an opinion with reference to the specific question that has to be answered.

As courts became more familiar and accepting of psychologists as experts they also started to increase their expectations of them. This led to the development of the field of forensic psychology. Practitioners in this specialty are experts in specific areas of psychology (e.g., adult mental health) who have knowledge of particular areas of law and the skills required to undertake legally defensible investigations, write reports, and testify in order to answer questions posed by the courts. Whilst it may appear to the uninformed that the knowledge and skills of generalist psychologists are sufficient to undertake these activities, this is not the case. Since the 1970s there has been a massive increase in research around forensic work and this has led to the development of specialist forensic assessment tools and techniques. For instance, the literature indicates that forensic investigations differ notably from clinical investigations, and forensic interviewers require investigative interviewing skills to ensure the integrity of the data on which they base their opinions (Greenberg & Shuman, 1997).

Ethical challenges in court work

The downside of the greater acceptance of psychologists in court is the relatively high number of ethical complaints lodged against them for court related activities. This is understandable to a point. First, the practice of psychologists who testify in court, even as witnesses of fact, is often scrutinised to a degree that is rarely experienced in other settings (see, for example, the cross examination reported by Bartholomew, 1992). Flaws in the professional conduct and performance of psychologists are therefore often exposed during court proceedings.

Secondly, the parties involved in legal proceedings experience heightened emotions, feel vulnerable, and often stand to suffer noteworthy losses. They are therefore very sensitive to any behaviour that is perceived to be disrespectful of them or their rights, and there is consequently an increased risk that they will make complaints against psychologists with whom they are dissatisfied. There is sometimes a factual basis for these complaints as the conduct and performance of some psychologists is substandard, whilst others exceed their competency when they do court work (e.g., expressing opinions beyond their competence). There are also, unfortunately, some complaints that are vexatious or aim to intimidate psychologists. However, close scrutiny, high emotions, and a degree of legal game-playing are inherent in legal proceedings.

Principles underlying ethical forensic psychology practice

The only way that psychologists can minimise the risk of becoming respondents in disciplinary proceedings is by practising in a legal and ethically appropriate manner at all times, and being extraordinarily vigilant when they do court related work. To achieve this they should be guided by the ethical principles (Allan, 2010) that underlie the APS Code of Ethics (2007).

In the adversarial environment of litigation, for instance, psychologists may lose sight of the principle of respect for the dignity and rights of other people. They therefore often do and say things, or use language in court reports, that the parties and their colleagues find disrespectful. Whilst the court environment is more robust than most other environments where psychologists work, psychologists must still at all times "communicate respect for other people through their actions and language" (APS Code of Ethics, Standard A.2.1.a). When they are asked to comment on the qualifications and practice, or critique the reports, of colleagues, psychologists should do so in an objective and cautious manner and avoid intemperate criticism. Excessive and unfair comments about another psychologist are not only disrespectful, but also violate an aspect of the principle of responsibility, namely that psychologists should avoid engaging in conduct that reflects negatively on the profession or discipline of psychology (Standard C.1.2). This does not mean that psychologists should not be honest. The veracity principle is firmly entrenched in the Code and psychologists, like all witnesses, are expected to be truthful, but they must be honest in a respectful way.

The respect principle also requires psychologists who do court work to safeguard the confidentiality of information obtained whilst providing psychological services (Standard A.5.1). However, this ethical rule is limited by the legal expectation that witnesses should at all times be honest and objective. The potential conflict between psychologists' duty to protect their clients' confidentiality and their duty to be truthful is of particular concern where clients subpoena psychologists to give testimony as treatment experts. Clients often fail to appreciate that psychologists may be required to provide evidence under cross examination that could be detrimental to their case. Psychologists who are asked to testify as treatment experts must keep in mind that they will be engaged in a dual relationship in that they have a duty to protect the interests of their clients (General principle B) whilst courts' believe that "an expert witness's paramount duty is to the court and not any party to the proceedings" (Willoughby v TICD, 2008, para. 3). This is in sharp contrast to psychologists' obligations under the fidelity principle, which requires them to give precedence to their clients' interests over those of others.

This conflict of interest can put treatment experts in the predicament that they may have to provide information to courts while knowing that the evidence could harm their clients or their clients' cases. Given that Standard C.3.1 of the Code provides that psychologists should refrain from engaging in multiple relationships that may "impair their competence, effectiveness, objectivity, or ability to provide a psychological service" or "harm clients or other parties", psychologists should try to avoid testifying as treatment experts. This is not always possible, but the principle of beneficence (the duty to do good) requires psychologists to at least warn all clients in advance that there are limitations to the confidentially of the information shared during sessions (see Jifkins, 2010). They must in particular tell their clients that they will be required to tell the truth in reports they write to courts or in evidence if they are subpoenaed (see Jifkins, 2008, for a discussion of subpoenas). Psychologists should recommend to clients who nevertheless wish to subpoena them that they should consider requesting their lawyer to engage the services of a forensic psychologist instead. This will prevent the treating psychologist from engaging in multiple relationships, and in all likelihood the case of the client will be better served because the evidence of an independent psychologist based on a competent forensic assessment is likely to carry more weight in court.

Ethical principles underpinning forensic psychology practice

  • Respect for the dignity and rights of other people
  • Responsibility to clients, society and the profession
  • Veracity (i.e., be honest and truthful)
  • Fidelity (i.e., entrusted with clients' interests)
  • Beneficence (i.e., do good)
  • Non-maleficence (i.e., do no harm)
  • Justice (i.e., be fair and objective)


Multiple relationships in court work are not restricted to psychologists who testify about their clients. Psychologists who subsequently treat people who they have assessed for a court report, or who undertake a forensic investigation for a lawyer who is a family member, are also engaged in avoidable multiple relationships that could impair their ability to provide appropriate services.

An aspect of the non-maleficence principle (the duty to avoid harm) that is of particular relevance to psychologists engaged in court work is competence. Treatment experts in particular should ensure that they do not express opinions about a diagnosis or treatment that is beyond their professional competency. Forensic psychologists should only provide opinions if they are specialists in the relevant area. For instance, experts in developmental psychology should refrain from expressing opinions on the mental health of a parent in a family court case unless they are also experts in adult mental health. They should also be able to undertake a competent forensic investigation. Psychologists should keep in mind that both in ethics and law the conduct of people is judged with reference to the activity they are involved in. If generalists therefore undertake specialist activities, such as forensic work, they will be judged by the standards expected of a specialist.

Not surprisingly given the context, the justice principle is probably one of the most important ethical principles psychologists who engage in court work should take into account. This principle requires psychologists to be fair and objective. At the most basic level this implies that psychologists should not express an opinion about a person whom they have not assessed. Especially in family court work psychologists are often lured into expressing an opinion about the spouse of a client whom they have not assessed. However, in certain very limited situations where suitable collateral information has been carefully reviewed, appropriately trained forensic psychologists could express an opinion about an individual whom they have not personally interviewed if they are accepted as an expert by a court or tribunal (e.g., in regards to a psychological autopsy of a deceased person or an opinion regarding the recidivism risk of an individual who refuses to be interviewed). In such cases psychologists must explicitly note the limitations of their opinion, clearly document their sources of information, not overstate their opinion, and strive to be as objective as possible.

Inappropriate roles and sources of bias in forensic psychology

As noted above, the role of treating clinician is incompatible with that of forensic assessor. Indeed, in most forensic assessments the individual being assessed will not be the forensic psychologist's ‘client' per se. Rather, the client will be the referring agency, be it solicitor, barrister or court. Moreover, the forensic psychologist has a duty to provide impartial evidence to the court. Therefore, it is crucial that forensic psychologists adopt an appropriate truth seeking professional role. Despite the need for impartiality, psychologists may inadvertently find themselves adopting inappropriate professional roles whilst performing forensic assessments. Several of these have been described in the literature (e.g., Davis, 2008b; Dietz, 1996) and it is important for forensic psychologists to be aware of them.

One is the therapeutic role during the forensic assessment. This can be a difficult role to avoid, especially when one has been trained as a clinical psychologist or is otherwise involved in treatment work. Some assessors will naturally, and perhaps understandably, find themselves adopting a pseudo-therapeutic role during assessments which can interfere with the truth seeking investigative role of forensic work. Such role confusion can seriously bias and undermine the forensic psychologist's duty to the court.

Another problematic role occurs when psychologists act as advocates for a cause. Some mental health professionals hold very strong opinions about a range of issues, such as involuntary treatment or detention, which may be relevant to particular court proceedings. In some cases psychologists may find themselves offering opinions that serve to advance their cause rather than advising the court about the case at hand. Dietz (1996) described this as the misplaced lobbyist phenomenon and suggested that "such experts are testifying before the wrong branch of government" (p. 155). Advocacy for a cause can be very noble when lobbying for change. However, it has no place in forensic assessment or the court room.

Similar problems can occur when forensic assessors are unduly influenced by their personal views of the offender or their offences. These can bias the assessor in either direction. In some cases psychologists may identify with offenders or perceive them solely as victims of abuse and deprivation, thereby minimising their responsibility. In other cases the psychologist may identify with the victim and inadvertently focus upon the heinous nature of the offence. In both instances psychologists' truth seeking role and duty to the court can be compromised.

A further problematic role is that of advocate for a party, where psychologists find themselves providing evidence that is, to some degree, biased towards a particular side in a legal dispute (usually the referring agency). This can be quite blatant and gives rise to pejorative terms such as hired gun, whore of the court, and the somewhat grandiose battle of the experts. While one would hope that overt and blatant advocacy is not widespread amongst forensic mental health professionals, the scholarly literature suggests that some bias exists (see Otto, 1989; Rogers, 1987). For example, Murrie and colleagues (2008) reviewed inter-rater agreement for scores on the Hare Psychopathy Checklist-Revised during sexually violent predator trials in Texas. They found large discrepancies between the scores reported by experts retained by different sides. In most cases this difference was in the direction of the side that retained the expert and was larger than the standard error of measurement (which is approximately three; Hare, 2003). Alarmingly, one expert was found to be 20 points higher than another expert when retained by the petitioner and 14 points lower when retained by the respondent.

Inappropriate ‘roles' for forensic psychologists in court

  • Therapeutic
  • Advocate for a cause
  • Espousing strong personal views
  • Advocate for one party in a dispute


These results are certainly concerning. However, in many cases some discrepancies may not necessarily reflect intentional advocacy. The nature of forensic work, particularly that of the private practitioner, often involves referrals from solicitors or barristers who are understandably seeking information that is helpful to their case. Indeed, legal practitioners must pursue their cases with zealous advocacy, which can clash with forensic psychologists' requirement for objectivity. Some referrals will involve rather blatant suggestions of what the lawyer is hoping the psychologist will find, whilst others provide more subtle suggestions that may influence the psychologist's opinion. Zusman and Simon (1983) suggested the term ‘forensic identification' to describe "the unintentional process by which clinicians adopt the fact pattern or theory of attorneys with whom they have initial contact. This process skews their clinical findings and distorts their conclusions" (p. 151).

The forensic psychologist may also be influenced to some degree by other subtle concerns. For example, some legal practitioners may request that psychologists make changes to their reports. In some situations these are justified, such as when a factual error is identified. However, requests to change opinions may place psychologists under some pressure in regard to future referrals if they refuse (which of course cannot be a consideration). A more understandable influence is concern over what will happen to the offender if the psychologist gives a decidedly negative opinion. This is related to problems with adoption of the therapeutic role alluded to earlier.

The investigative forensic scientist role

Given the potential for various inappropriate roles and influences that may affect psychologists' opinions in forensic matters, it is important that the practitioner acknowledges these sources of bias in adopting an appropriate investigative stance. Accordingly, the role of forensic mental health professional should be the same as any other forensic scientist. Dietz (1996) noted that "my touchstone for grappling with apparent moral conflicts has always been to ask myself what the ideal forensic pathologist would do in a similar situation" (p. 156). Indeed, many of the above sources of bias disappear, or at least pose less of a conflict, when psychologists view themselves as truth seeking investigative forensic scientists. As such, forensic psychologists need to focus upon the referral question(s), describe the evidence for their opinion, be balanced and consider alternative hypotheses, and have a total disinterest in what the outcome of the legal dispute may be. Admittedly, such a detached and dispassionate role differs from many other areas of psychology and is one which many may find distasteful. However, it is a crucial role to adopt in order to fulfil our truth seeking role for the court, and underscores the need for specialist training in forensic psychology.


The increase in training and research in forensic psychology and the development of specialist techniques and tools for court assessments have made it a specialist activity that is beyond the competence of generalist psychologists. It is possible that the demand for psychologists with forensic competencies will increase in the future as courts realise how useful the services of psychologists with these skills are. Some courts are already indicating that they expect all psychologists who engage in court work, even those who are experts in an area of psychology like neuropsychology, to have forensic training, knowledge and skills.

Psychologists who do court work as expert witnesses may therefore run the increasing risk of being the target of ethical complaints and even legal action if they lack these forensic competencies. At the same time knowledge and skills in specialist areas of psychology are increasingly leading to the emergence of highly specialised psychologists, such as forensic neuropsychologists. As courts become more sophisticated about psychology they also tend to be more critical of the evidence of witnesses of fact and, especially, treatment experts whose opinions and objectivity are likely to be viewed with a greater degree of scepticism. This paper has discussed the ethical challenges and potential for adoption of inappropriate roles when acting as a witness for the courts. Moreover, it has highlighted the need for specialist training in the discipline of forensic psychology for those who undertake this demanding work.

The authors can be contacted at and


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InPsych August 2010