To what extent should expert psychiatric witnesses comment on criminal culpability?

Introduction

Expert psychiatric evidence is often admitted in court to enable a defendant’s mental disorder to be taken into account. In some cases, this may be a practical necessity. ¹ Nevertheless, psychiatric evidence is only admissible if it is outside the experience and knowledge of a judge or jury and relevant to the case. ² It is possible for an expert to step outside their area of expertise by commenting on an ultimate issue. ³ An ultimate issue is a legal issue which must be made by the court such as whether a defendant had an intention or whether they should be found guilty. The determination of culpability is also an ultimate issue which should be made by the court rather than by experts.

Determining culpability is essential when sentencing mentally disordered offenders both in determining the type of disposal such as a hospital order as opposed to a custodial sentence and in mitigation in potentially reducing that sentence. Mental disorder may also be an aggravating factor leading to a more severe sentence. The Court of Appeal case of R v Vowles ⁴ in England and Wales gave prominence to hybrid orders which direct an initial period in hospital with transfer to prison once treatment in hospital is complete. Six appellants who were serving indeterminate custodial sentences for public protection appealed on the basis of new psychiatric evidence that they should be given hospital orders with restrictions, three of whom were successful. In addition to raising the issue of the most appropriate release regime, Vowles raised the importance of determining culpability because of the need to determine the extent to which punishment was required, given that hybrid orders include an element of punishment. There had to be sound reasons for departing from the usual course of imposing a custodial sentence. Following Vowles, the assessment of culpability in mentally disordered offenders has become increasingly difficult for the courts ⁵ and ethically problematic for psychiatrists contributing to decisions about punishment. ⁶

Culpability is the degree to which a person can be held morally or legally responsible for their conduct and has traditionally been strongly linked to their mental state at the time of the offence. ⁷ Mental disorder is usually considered to reduce culpability, ⁸ but the specific ways in which this occurs is unclear. Developments in neuroscience suggest that executive function may play a central role in culpability because of the need to have sufficient capacity for moral responsibility. ⁹ Some however, have been more sceptical about whether neuroscience or psychiatry can answer questions of culpability.^10,11 This is partly because of the fundamental mismatch between science and the law. ¹² Peay argues that part of the confusion is one of language, since the terms ‘responsibility’ and ‘culpability’ are often used interchangeably. She argues that it is more helpful to use ‘responsibility’ as the binary concept of being guilty or not guilty, and ‘culpability’ as the degree of blameworthiness for those who are responsible, ¹³ a convention which will be followed in this article. The water is further muddied by the defence of diminished responsibility which has been explored elsewhere. ¹⁴

R v Edwards

The recent Court of Appeal case of R v Edwards ¹⁵ in England and Wales aimed to clarify Vowles and added principles for the sentencing of mentally disordered offenders. These included an assessment of culpability:

To decide whether a penal element to the sentence is necessary the judge should assess (as best he or she can) the offender's culpability and the harm caused by the offence. The fact that an offender would not have committed the offence but for their mental illness does not necessarily relieve them of all responsibility for their actions.

More recent cases in England and Wales show a similar trend. In R v Yusuf, ¹⁶ three different psychiatrists were asked explicitly about culpability, one arguing that it was in the medium range and the other two arguing that culpability remained despite psychotic symptoms because of the voluntary nature of taking illicit substances. In R v Ozone, ¹⁷ one psychiatrist argued that the appellant’s culpability was low. The court later rejected this, saying that his role was to give his opinion on the mental condition of the appellant and its effect, but that the assessment of culpability was a matter for the judge. Nevertheless, the court did not necessarily criticise him for commenting on culpability but merely disagreed with his assessment of it.

The problem with asking psychiatrists to comment explicitly on culpability is that culpability is not a medical concept. Although mental disorders may have a bearing on culpability, other non-medical factors are also relevant. The courts appear to be asking psychiatrists to answer questions outside their area of expertise.

What is culpability?

Defining culpability has proved difficult, partly because the nature of culpability varies depending on the type of offence. Culpability may relate to acting intentionally, knowingly, recklessly or negligently, and is complicated by justifications or excuses such as acting in self-defence or under duress. Most theories of culpability are based on Kantian concepts of choice or on Aristotelian concepts of character traits. ¹⁸

Choice theory, ¹⁹ which may include concepts of capacity, is about how a person chooses to act when they could have chosen to act differently. Choice theory reflects the mens rea of choosing to act intentionally, knowingly or recklessly, but faces difficulties with crimes of negligence where certain elements of an offence require no mens rea at all, and a person appears not to have made a choice. The same could be said for impulsive behaviour, which even if chosen is not done after any meaningful reflection. Choice theory also appears to be inadequate to explain the difference in culpability between criminal attempts and actual harm because in both instances, the choice is the same.

One philosophical problem with choice theory is whether we are really free to make choices at all, given that our choices are affected by our backgrounds and personalities, neither of which we have chosen. Some argue for a deterministic view of the universe in which there is no free will, ²⁰ although Morse argues that this is not a problem because it is rationality rather than free will which makes someone culpable. ²¹ In practice, however, it is almost impossible to distinguish between those who had the moral capacity to act differently but chose not to from those who lacked the moral capacity to act differently and could not have chosen otherwise. ²² Although some argue that forensic psychiatrists should think about free will, ²³ others are less sure because of the overlapping domains of psychiatry, law and philosophy. ²⁴

Character theory ²⁵ treats someone as culpable for their criminal acts insofar as they are a product of their character traits, which are relatively stable patterns of thought and behaviour. Character theory explains why people are given lesser sentences if they are of previously good character. It might explain why people can be culpably negligent if it is their disposition to be careless, but one might ask to what extent we are responsible for our characters. ²⁶ One difficulty with character theory is deciding what counts as being out of character, given that character is defined by previous conduct. This is especially the case for a first criminal offence at a relatively young age before one’s character has developed. Character theory is also problematic when it comes to mentally disordered offenders because of the difficulty in deciding whether someone’s conduct is part of their character or part of their mental disorder, particularly in cases of personality disorder where their character is the mental disorder.

Other theories besides choice theory and character theory also find mental disorders difficult to take into account. Agency theory ²⁷ evaluates conduct like a target in archery by how close it hits the intended target. The target is harm as it was intended, away from the centre is less harm than was intended and furthest away are crimes of negligence. Agency theory cannot, however, explain the lower culpability ascribed to mentally disordered offenders who intend certain harms due to their psychotic symptoms for example. Role theory ²⁸ describes criminal conduct as occurring when we fall below the standard of a reasonable person in the role we perform. Nevertheless, mental disorders can also affect a person’s ability to behave reasonably in a role and should not in themselves be criminalised. Defiance theory ²⁹ considers criminal conduct to be that which is done in deliberate defiance of the law. Crimes of negligence pose particular problems for this because by definition they are not done knowingly. Mental disorders may contribute to negligent behaviour and reduce a person’s knowledge of their actions. If this amounted to insanity, which is considered below, then they may be said not to be acting in defiance of the law, but many mental disorders may contribute to negligence without amounting to insanity. The absence of a coherent theory of culpability is unsurprising, given that the law evolves pragmatically over time and is shaped by cultural attitudes. Furthermore, certain theories of culpability may favour particular mental disorders over others in terms of the level of their culpability.

Culpability within legal systems

Part of the complexity in assessing the contribution of mental disorder to culpability is that culpability exists within defined legal systems. Brants et al. compared concepts of culpability in England and Wales with that of the Netherlands and linked the degree of culpability to a defendant’s capacity. ³⁰ They argue that whether a system is adversarial, as in England and Wales, or inquisitorial, as in the Netherlands, affects the way in which mental disorder is translated into legal culpability. They point out the existence of a general diminished capacity defence in the Netherlands which reflects degrees of culpability: undiminished, somewhat diminished, diminished, highly diminished and total incapacity. By contrast, in England and Wales, the presence of a mental disorder rarely prevents a defendant being responsible and therefore guilty of an offence. A defendant can only be found to have diminished responsibly in murder cases, or not be culpable at all in cases of insanity or automatism. This is notwithstanding that within the offence of diminished responsibility, there are still degrees of culpability, as described in R v Jenkin. ³¹ Brants et al. argue that the adversarial system in England and Wales may explain why the concept of partial capacity is lacking compared to the Netherlands.

The complexity of translating the effects of a mental disorder into legal culpability was explored in the Australian case of R v Verdins ³² which established that mental disorder may reduce culpability if it did any of the following: impaired the offender’s judgement, impaired their ability to make rational choices or to think clearly, made the offender disinhibited, impaired their appreciation of the wrongfulness of their conduct, obscured their intent or contributed causally to the offence. Although psychiatric evidence may have a bearing on all of these factors, Bargaric has criticised them for being too vague. ³³

In discussing the determination of culpability, Bargaric draws attention to the Australian case of DPP v Weidlich ³⁴ in which it was stated:

The measure of culpability of an offender under the criminal law rests upon the extent to which the individual can be seen to be personally responsible for both the prohibited acts and their consequences. Little thought is required to appreciate that the greater the level of insight and understanding possessed by him or her concerning the act and its potential harm, the higher becomes the level of culpability for then deliberately engaging in the conduct involved.

The Sentencing Council consultation

The Sentencing Council in England and Wales has recently published a draft consultation document on the sentencing of mentally disordered offenders which includes guidance on assessing culpability. ³⁵ They state that the following factors may relate to culpability: Impaired ability to exercise appropriate judgement, impaired ability to make rational choices or to think clearly, impaired ability to understand the nature and consequences of their actions, disinhibition, elements of premeditation or pre-planning, attempts to minimise their culpability, insight into their illness, help seeking, lack of compliance with medication and whether it was linked to their mental disorder, and their awareness of the effects of alcohol or illicit drugs on their mental disorder. These factors appear to be similar to the Verdins principles above. Although many of these factors do relate to psychiatric matters such as insight, others appear not to, such as premeditation or minimising their culpability.

The general guidance in the draft Sentencing Council consultation document states that culpability will vary between cases and that sentencers are not bound by expert opinion. Nevertheless, it says that following expert opinion may not be appropriate if an expert suggests a diagnosis without ‘a clear indication of how it affects culpability’. This implies that experts may and perhaps ought to comment explicitly on culpability, even though not all relevant factors are psychiatric in nature.

Mental disorders and crimes of recklessness or negligence

There are particular challenges in assessing the culpability of mentally disordered offenders in cases of recklessness or negligence. Recklessness requires that one knowingly exposes unnecessary risks to others. In England and Wales, the test of recklessness has traditionally been a subjective one. The defendant had to have foreseen a particular kind of harm. ³⁶ Although R v Caldwell ³⁷ introduced an objective element, it was enough that a reasonable person would have foreseen the risk; this was overturned in R v G. ³⁸ Nevertheless, it is possible that recklessness does not necessarily mean the same thing in every context. ³⁹

Certain mental disorders may increase reckless activity, ⁴⁰ but defendants can still be convicted of recklessness if they were able to foresee the consequences of their actions such as in cases of adjustments disorder ⁴¹ or personality disorder. ⁴² Mental disorder may, however, reduce culpability completely. In R v Stephenson, ⁴³ a defendant with schizophrenia, who had set fire to a haystack where he had slept in order to keep warm, was acquitted on the basis that he was unable to foresee the risks of his fire setting. The fact that a reasonable person would have foreseen the risks was irrelevant. Psychiatrists may therefore give evidence as to the effect of a mental disorder on a defendant’s appreciation or knowledge of certain risks in addition to their likelihood of taking those risks.

Crimes of negligence involve inadvertently taking a risk which a defendant ought to be aware of but isn’t. The standard of what is reasonable is an objective test. Other jurisdictions have different approaches to the distinction between recklessness and negligence and where the objective/subjective distinction lies. ⁴⁴ Mental disorder arguably makes the application of an objective test unfair because it may significantly change a defendant’s knowledge and perception of the world, making them more likely to be negligent. Although there is broad support for the concept of criminal negligence, ⁴⁵ Alexander and Ferzan argue that crimes of negligence should never be culpable. ⁴⁶ Moore and Hurd ⁴⁷ argue that some types of negligence can be culpable if they involve failing to take precautions to avoid certain risks or failing to improve one’s character which led to the taking of such risks.

Crimes relating to causing death by driving have a spectrum of culpability, at the lower end of which are crimes of negligence. ⁴⁸ In England and Wales, in R v Williams, ⁴⁹ it was pointed out that death by careless driving ⁵⁰ holds the lowest level of culpability compared to death by dangerous driving, manslaughter or murder. Death by careless driving could be due to momentary inattention but is an objective test. ⁵¹ If momentary inattention is all that is required, however, then it is difficult to see how a person is really culpable, since unless they have a disposition to be careless, neither their choice nor character led them to have momentary inattention; they may just have been unlucky. Mental disorder can increase the likelihood of momentary inattention, but as long as the defendant’s mental disorder did not lead them to being in a state of automatism or insanity, it will not prevent them from being found guilty.

Insanity and moral ignorance

Insanity is a common law defence to any criminal charge ⁵² and exculpates the defendant completely, giving them the special verdict of not guilty by reason of insanity. It derives from the case of M’Naghten and applies if a defendant is labouring under such a defect of reason from disease of the mind as not to know the nature and quality of the act he was doing or, if he did know it, that he did not know that what he was doing was wrong. ⁵³ Although the exact reason for a lack of culpability in M’Naghten insanity is debated, ⁵⁴ it appears to be related to a lack of moral knowledge which reduces culpability completely.

McChesney and Doucet use the insanity rules as evidence that culpability should relate to the degree of ‘moral concern’ a defendant has. ⁵⁵ They argue that this model of culpability explains why crimes of negligence can sometimes be culpable because even though a person did not intend to cause harm, they did have a lack of moral concern. They argue, however, that if a person’s negligence is caused by their mental disorder rather than their own lack of moral concern, then they should not be culpable. They argue that conditions such as intellectual disability, autism spectrum disorder, attention-deficit/hyperactivity disorder, generalised anxiety disorder and depression can all cause a person to fail to notice things, including the moral status of their conduct. Nevertheless, it is difficult to separate a lack of moral concern associated with certain mental disorders from a defendant’s own character. This is particularly the case for psychopathy.

Psychopathy is one of the most controversial disorders from a culpability perspective. Psychopathy as measured by Hare’s Psychopathy Checklist Revised (PCL-R) ⁵⁶ includes traits such as being manipulative, deceitful, lacking remorse and lacking empathy. PCL-R scores also appear to predict reoffending ⁵⁷ which causes concern from a public protection perspective. Unsurprisingly, most people want psychopaths to be culpable, even though many academics consider them to have impairments in moral reasoning, ⁵⁸ emotional sensitivity, ⁵⁹ executive function ⁶⁰ or rationality. ⁶¹ Alexander and Ferzan go as far as to argue that pure psychopaths with total moral blindness no more deserve punishment than lions or sharks. ⁶² The problem with McChesney and Doucet’s ‘moral concern’ definition of culpability is that psychopathy is to some extent defined by a lack of moral concern, yet it is rarely treated as a reason for mitigation or lower culpability. It is certainly tempting to start with our desired outcome and construct an account of culpability to fit. ⁶³ Expert witnesses should therefore be careful not to let their own value judgements about culpability for particular disorders bias their evidence.

The role of expert psychiatric witnesses

Although psychiatrists are increasingly being asked to give evidence in relation to culpability, the theoretical problems with defining culpability from a philosophical and legal perspective should be apparent. Even if these are set aside, translating the effects of a mental disorder into culpability is complex. Particular types of crimes and particular mental disorders raise questions which are not necessarily psychiatric in nature, such as the following: Does having a personality disorder associated with impulsivity in crimes of recklessness reduce someone’s appreciation of the consequences of their actions and therefore reduce their culpability, or increase the likelihood of taking risks and therefore increase their culpability? Does having a depressive disorder which contributes towards carelessness when driving make someone less culpable compared to someone who is equally careless but without a mental disorder? If someone with schizophrenia stops their medication against medical advice, are they still culpable, even if their lack of insight into the need for medication is part of their disorder? The answers to these questions are not immediately obvious.

Although the effects of a mental disorder on a specific choice or action will always be case specific, there are some areas within psychiatry which are more closely linked to culpability than others. Some of the abilities in Edwards and Verdins and the draft Sentencing Council consultation guidelines above may legitimately be addressed by psychiatrists if they are underpinned by scientific research. To the extent that a defendant’s mental disorder affects these abilities, an expert may comment on the following: capacity and insight into their mental disorder, ⁶⁴ thinking skills, ⁶⁵ degree of choice, ⁶⁶ decision-making abilities, ⁶⁷ help-seeking behaviour, ⁶⁸ use of illicit substances, ⁶⁹ disinhibition, ⁷⁰ risk-taking behaviours, ⁷¹ the contribution of the mental disorder towards their offence ⁷² and their insight into their risks to others. ⁷³

When it comes to commenting on rationality, expert psychiatric witnesses can be too quick to equate psychiatric disorders with irrationality. ⁷⁴ There is confusion in the area of diminished responsibility where the courts have conflated impairments in rationality with both morality ⁷⁵ and merely logical thought processes. ⁷⁶ Given that none of us are entirely rational all of the time, psychiatrists should be wary of using the language of rationality to describe mental disorders. Instead, they should describe the effect of a mental disorder on a defendant’s thought processes, such as the presence of delusions or depressive cognitions. Although some have argued that rationality is closely linked to capacity and culpability, ⁷⁷ these are not equivalent concepts, and psychiatrists have no expertise in pronouncing on the relationship between them.

Commenting on a defendant’s awareness of the nature or wrongfulness of their actions is essential in cases of insanity. ⁷⁸ Psychiatrists are not, however, experts in morality and should exercise caution when pronouncing on a defendant’s moral framework. A finding of insanity based on psychiatric evidence is usually made by a jury, who are better placed to judge issues of morality. Instead, psychiatrists should comment on the effect of a mental disorder on a person’s thought processes, which may affect their appreciation of wrongfulness, but the ultimate issue should be left to the jury. Although it could be argued that psychiatrists should therefore comment on the appreciation of wrongfulness in every case, this should be strongly resisted because of the danger of stepping outside their area of expertise.

Giving an opinion on capacity to form an intent must be done with particular care. The Verdins principles include how a mental disorder may have obscured a defendant’s intent. Psychiatrists must never pronounce on the actual intent of the defendant, as this is a matter for the court. Describing how a mental disorder might obscure such an intent comes dangerously close to doing so, as it depends on what the actual intent is. Nevertheless, psychiatrists could legitimately make the point that mentally disordered offenders are often still capable of forming intentions, despite their psychiatric symptoms. This has been explored in relation to a case of depersonalisation where it was stated by one expert in the context of grievous bodily harm that ‘a depersonalised intent is nevertheless an intent’. ⁷⁹ This expert used the behaviour of the defendant – in this case, his intention to get a tool from his garage – to comment on the likely capacity of the defendant to form a specific intent at the material time. The other expert stated that ‘I am in no doubt that he did not form an intent’, an opinion which appears to pronounce on the actual intent of the defendant on which it is never appropriate for an expert to comment. Experts would do well to avoid the danger of pronouncing on intent by making their opinions conditional, such as ‘if the court finds that despite being in a state of depersonalisation the defendant had the intention to get a tool from his garage, he would also have been able to form an intention to commit grievous bodily harm’.

There are some areas relating to culpability on which psychiatrists should never comment. The draft Sentencing Guidelines consultation document lists as areas of culpability elements of premeditation or pre-planning and attempts to minimise their culpability. Although psychiatric evidence may be relevant to a defendant’s ability to plan, such as in frontal lobe impairment, ⁸⁰ whether they did in fact plan to commit a crime must remain a matter for the court. Similarly, if a mental disorder contributes to behaviour which might be wrongly interpreted as deliberately concealing their actions, psychiatrists may comment on it, but they should never pronounce on whether a defendant attempted to minimise their culpability.

Whether an expert may give evidence relating to the above depends on whether it is an area in which he or she has expertise. Even if psychiatric evidence is admissible, experts should not ‘join up the dots’ and give a definitive view on the actual level of culpability. This is both because there are other non-medical factors which have a bearing on culpability and because culpability itself is a legal rather than a medical concept and is an ultimate issue for the court.

Conclusions

Despite the theoretical problems with defining culpability, the assessment of a defendant’s culpability is central to the criminal justice process. Assessing the culpability of mentally disordered offenders poses particular difficulties because of the uncertain relationship between the medical concept of mental disorder and the legal concept of culpability. The role of expert evidence may, however, be paramount, and some of the psychiatric areas relating to culpability which may be legitimately commented upon by experts have been suggested. Nevertheless, there is a danger that when determining the level of culpability, judges will show no reluctance in asking psychiatrists to comment on it explicitly. This should be resisted both because of non-medical factors involved in the determination of culpability and because even if mental disorder were to correlate with concepts of culpability, it is ultimately a matter for the court. To give an opinion on the overall level of culpability is to step outside one’s area of medical expertise and to pronounce on issues of guilt and blame.