In Henderson v Dorset Healthcare University NHS Foundation Trust [2020] UKSC 43  the Supreme Court dismissed an appeal on the grounds that the claimant’s action was based on illegality. It found that someone found guilty of manslaughter due to diminished responsibility should not be able to bring an action for damages against an (admittedly) negligent health authority.


Mrs Henderson suffers from from paranoid schizophrenia or schizoaffective disorder, she was under the care of the defendant health authority. In August 2010 she stabbed and killed her mother whilst undergoing a serious psychotic episode. She was convicted of manslaughter by reason of diminished responsibility.  She brought proceedings against the defendant arguing that it was negligent in failing to care for her. The defendant admitted it was negligent but argued that Mr Henderson’s claim was barred for illegality.



Lord Hamblen, giving a unanimous judgment, stated that the damages sought in this matter were not recoverable because of House of Lords in Gray v Thames Trains Ltd [2009] UKHL 33; [2009] AC 1339 .


It was held that Gray could not properly be distinguished.  The court was not willing to depart from Gray.   A number of reasons were put forward, these were all rejected.



Lord Hamblen considered the arguments put forward in favour of Mrs Henderson.
  1.  These are formidable arguments persuasively presented by Mr Bowen QC on behalf of the appellant and supported by some academic commentary, in particular the writings of Dr Dyson. I am, however, unable to accept that they meet the high hurdle of justifying departure from the House of Lords’ relatively recent decision in Gray.
  2.  As explained above, the key consideration as far as the majority in Gray were concerned was that the claimant had been found to be criminally responsible for his acts. That he had been convicted of manslaughter on the grounds of diminished responsibility meant that responsibility for his criminal acts was diminished, but it was not removed. It was not an insanity case and so, as Beldam LJ pointed out in Clunis (at p 989): “he must be taken to have known what he was doing and that it was wrong”.
  3.  In such circumstances, the majority in Gray justifiably considered that inconsistency would arise not only if he was allowed to recover damages resulting from the sentence imposed, but also if they resulted from the intentional criminal act for which he had been held responsible. To allow recovery would be to attribute responsibility for that criminal act not, as determined by the criminal law, to the criminal but to someone else, namely the tortious defendant. There is a contradiction between the law’s treatment of conduct as criminal and the acceptance that such conduct should give rise to a civil right of reimbursement. The criminal under the criminal law becomes the victim under tort law.
  4.  Whilst the wider rule may not involve, as the application of the narrower rule does, the law giving with one hand what it takes away with the other, it does involve, as Lord Hughes said in Hounga v Allen at para 55, the law condoning “when facing right what it condemns when facing left”.
  5.  If, as the appellant submits, the degree of personal responsibility is a matter for the trial judge to determine in the civil claim there is a clear risk of inconsistent decisions being reached in the criminal and the civil courts, both as to the degree of responsibility involved and as to how that is to be determined. If, as is further submitted, it is appropriate for the civil court to move away from the M’Naghten approach to insanity, and to develop its own approach to such issues, then the inconsistencies will be heightened.
  6.  Nor does the fact that there may be no penal element to the sentence imposed by the criminal court alter matters. As Lord Rodger observed at para 78 of Gray, even if the sentence is not regarded as being a punishment, “this does not mean that the judge was treating the claimant as not being to blame for what he did”. A conviction for manslaughter by diminished responsibility still involves blame. The defendant would otherwise have been convicted of murder and some responsibility for the unlawful killing necessarily remains. Moreover, the fact of a criminal conviction for manslaughter is itself punitive.
  7.  A further difficulty with the appellant’s argument is why significant personal responsibility is to be regarded as the threshold, precisely what that means and how it is to be determined. Whilst a sentencing judge will be concerned with the level of responsibility involved, he or she will not be specifically addressing the issue of significant personal responsibility. If, for example, in accordance with the Guideline an offender is found to bear medium responsibility, how does that relate to the threshold of significant personal responsibility? In any event, any findings which may be made by the trial judge in the criminal proceedings will be solely for the purpose of sentencing.
  8.  It is not sufficient simply to say that this will be a matter of fact for the trial judge to determine in the civil claim. As the Law Commission’s Discussion Paper illustrates, the issue of responsibility raises questions of great complexity and difficulty. This fundamental building block of the appellant’s case was barely addressed in the appellant’s written case or in the 77-page speaking “note” provided on the first day of the hearing, a clear abuse of the written case procedure and its required page limits. Instead, the court was provided with a five-page insert to the speaking note which put forward the test of whether the claimant lacked capacity to conform their behaviour to the demands imposed by the criminal law. What the justification is for that proposed test was not really explained, nor was its meaning. Not only is it a recipe for uncertainty, but it risks being tantamount to judicial legislation.
  9.  Finally, the appellant advances a related argument that the lack of significant personal responsibility means that there is insufficient turpitude to give rise to an illegality defence. This again ignores the seriousness of a criminal conviction for manslaughter. It is an indictable-only offence punishable by a sentence of life imprisonment. It is a “serious offence” for the purposes of the provisions regarding dangerous offenders in the Criminal Justice Act 2003. The plea of guilty to manslaughter by reason of diminished responsibility means acceptance by the appellant that she possessed the mental prerequisites of criminal responsibility for murder, namely an intention to kill or to cause grievous bodily harm. In the present case, the expert psychiatrists also agreed that the appellant knew that what she was doing was morally and legally wrong when she inflicted the stab wounds on her mother. In Les Laboratoires Servier v Apotex Inc [2015] AC 430 Lord Sumption stated at para 23 that: “The paradigm case of an illegal act engaging the defence is a criminal offence.” As Lord Sumption explained at para 29, there may be some exceptional cases where a criminal act will not constitute turpitude. The reservation made in Gray in relation to trivial offences may be an example of such a case, as may be strict liability offences where the claimant is not privy to the facts making his act unlawful. The serious criminal offence of manslaughter by reason of diminished responsibility does not come close to falling within such an exception and clearly engages the defence.
(iii)     Whether the application of the trio of considerations approach set out in Patel leads to a different outcome.
  1.  The trio of considerations set out by Lord Toulson at para 120 of his judgment are:
(a)       the underlying purpose of the prohibition which has been transgressed and whether that purpose will be enhanced by denial of the claim (“the first stage” or “stage (a)”);
(b)       any other relevant public policy on which the denial of the claim may have an impact (“the second stage” or “stage (b)”); and
(c)       whether denial of the claim would be a proportionate response to the illegality, bearing in mind that punishment is a matter for the criminal courts (“the third stage” or “stage (c)”).
  1.  The issues and the arguments in the present case have raised a number of questions as to the proper understanding and application of the trio of considerations.
  2.  First, the appellant contends that the case should be remitted so that evidence can be adduced as to the suggested policy considerations, as to which there were various factual disputes. It is neither necessary nor desirable that consideration of the relevant policy considerations should give rise to a mini trial. They should usually be capable of being addressed as a matter of argument and at a level of generality that does not make evidence necessary, as is well illustrated by this court’s decision in Hounga v Allen.
  3.  Secondly, questions arise as to exactly how under the trio of considerations approach relevant policy considerations are to be weighed. It appears that this must involve a balancing between considerations arising at the first and second stages; the third stage relates to proportionality and factors specific to the case rather than general policy considerations. Stage (a) is directed at policy reasons which support denial of the claim and stage (b) is directed at policy reasons which support denial of the illegality defence. As Lord Toulson makes clear at para 101, stage (b) is meant to operate “conversely” to stage (a).
  4.  This is consistent with the approach of Lord Wilson in Hounga v Allen from which Lord Toulson had drawn support (at para 76). Lord Wilson described the balancing exercise in the following terms at para 42:
“So it is necessary, first, to ask ‘What is the aspect of public policy which founds the defence?’ and, second, to ask ‘But is there another aspect of public policy to which the application of the defence would run counter?’”
  1.  It also reflects the broad way in which Lord Kerr expressed his understanding of stage (a) at para 124:
“By this, I understand Lord Toulson JSC to mean the reasons that a claimant’s conduct should operate to bar him or her from a remedy which would otherwise be available.”
  1.  It follows that stage (a) should not be interpreted as being confined to the specific purpose of the prohibition transgressed. Whilst that is of great importance, other general policy considerations that impact on the consistency of the law and the integrity of the legal system also fall to be taken into account. In the present case, for example, that would encompass the public policy considerations identified in Gray, namely the consistency principle and the public confidence principle. Similarly, whilst preventing someone from profiting from his own wrong is not the rationale of the illegality defence, it is a relevant policy consideration, which is linked to the need for consistency and coherence in the law. For one branch of the law to enable a person to profit from behaviour which another branch of the law treats as being criminal or otherwise unlawful would tend to produce inconsistency and disharmony in the law, and so cause damage to the integrity of the legal system, as is recognised in Patel (at paras 99 to 101). In cases where it features, it too is a factor to be taken into account, even though it may not reflect the purpose of the prohibition transgressed.
  2.  In considering the issue of consistency and coherence in the law, the closeness of the connection between the claim and the illegal act may well be of relevance. The closer that connection is, the greater and more obvious may be the inconsistency and consequent risk of harm to the integrity of the legal system. The rejection by the majority in Patel of reliance as the test of illegality did not mean that reliance was thereby rendered irrelevant to the policy-based approach. It may not provide a satisfactory test of illegality, but it will often be a relevant factor.
  3.  Thirdly, questions arise as to the weight it may be appropriate to give to different policy considerations. At para 99 Lord Toulson recognised the importance of the policy considerations that a person should not be allowed to profit from his own wrongdoing and that the law should be coherent. Where either or both of these considerations are engaged it would seem appropriate that they are given great weight. This was a point made by Lord Kerr in his judgment at para 143 where he stated as follows:
“143.  Lord Toulson JSC’s solution to this question also permits readier access to investigation of the traditional justifications for the ex turpi causa maxim – preservation of the integrity of the legal system and preventing profit from wrongdoing. If, on examination of the particular circumstances of the case, these can be shown to weigh heavily in the balance, it is more likely that the defence will be upheld.”
  1.  I would respectfully agree with that approach.
  2.  Fourthly, questions arise as to whether proportionality always has to be considered and as to how it is to be addressed. In some cases, of which Hounga v Allen is an example, it may be apparent that the balancing of policy considerations comes down firmly against denial of the claim. If so, it will not be necessary to go on to the third stage and the issue of proportionality. This is consistent with Lord Toulson’s statement at para 107 that these factors relate to “whether it would be disproportionate to refuse relief to which the claimant would otherwise be entitled” and at para 101 that they fall to be considered to avoid “the possibility of overkill”. In other words, they are a disproportionality check rather than a proportionality requirement.
  3.  In relation to proportionality, at para 107 Lord Toulson identified four factors which were likely to be of particular relevance, namely: “the seriousness of the conduct, its centrality [to the transaction], whether it was intentional and whether there was marked disparity in the parties’ respective culpability.” Lord Toulson refrained from saying anything about the potential weight of such factors, no doubt to avoid being prescriptive. I would, however, suggest that centrality will often be a factor of particular importance. When considering the circumstances relating to the illegality, whether there is a causal link between the illegality and the claim, and the closeness of that causal connection, will often be important considerations.
(a)  Stage (a) – The underlying purpose of the prohibition which has been transgressed and whether that purpose will be enhanced by denial of the claim
  1.  As explained above, this stage involves identification of policy reasons which support denial of the claim. Considering first general policy considerations rather than the purpose of the prohibition, for the reasons explained in Gray, the consistency principle is engaged in this case. There is a need to avoid inconsistency so as to maintain the integrity of the legal system. Whilst that most obviously applies to the narrower rule, it also applies to the wider rule. As Patel makes clear, this is a central and very weighty public policy consideration.
  2.  For the reasons given by Lord Hoffmann in Gray, the public confidence principle is also engaged. Again, this applies to both the narrower and the wider rule.
  3.  In the present case, the gravity of the wrongdoing heightens the significance of the public confidence considerations, as does the issue of proper allocation of resources. NHS funding is an issue of significant public interest and importance and, if recovery is permitted, funds will be taken from the NHS budget to compensate the appellant for the consequences of her criminal conviction for unlawful killing.
  4.  This is also a case in which there is a very close connection between the claim and the illegality, thereby highlighting and emphasising the inconsistencies in the law which would be raised were the claim to succeed. The appellant’s crime was the immediate and, on any view, an effective cause of all heads of loss claimed. Indeed, applying Lord Hoffmann’s approach to causation in Gray, with which Lord Rodger and Lord Scott agreed, it was the sole effective cause of such loss.
  5.  In relation to the underlying purpose of the prohibition transgressed, an important purpose is to deter unlawful killing thereby providing protection to the public. As far as the public is concerned there could be no more important right to be protected than the right to life. It is clearly in the public interest that everything possible is done to enhance protection of that fundamental right. There is also a public interest in the public condemnation of unlawful killing and the punishment of those who behave in that way.
  6.  On behalf of the appellant it is submitted that it is absurd to suppose that a person suffering from diminished responsibility will be deterred from killing by the prospect of not being able to recover compensation for any loss suffered as a result of committing the offence. Indeed, more generally it is submitted that a person who is not deterred by a criminal sanction is unlikely to be deterred by being deprived of a right to compensation.
  7.  There is force in these points, but the question should not be considered solely at the granular level of diminished responsibility manslaughter cases. Looking at the matter more broadly there may well be some deterrent effect in a clear rule that unlawful killing never pays and any such effect is important given the fundamental importance of the right to life. To have such a rule also supports the public interest in public condemnation and due punishment.
(b)  Stage (b) – Any other relevant public policy on which the denial of the claim may have an impact
  1.  The appellant suggests four countervailing public policies.
  2.  The first is the policy of encouraging NHS bodies to care competently for the most vulnerable. It is said that it is recognised that imposing a duty of care can enhance standards. There is, however, no issue that a duty of care was owed. Indeed, liability for damages up to the date of the killing is admitted. It is unlikely that limiting the extent of the liability to the victim will affect the exercise of due care. In any event, there is a potential exposure in such cases to claims on behalf of victims as well as to regulatory sanctions. Focusing on the specific factual situation in the present case, there is no ready means of judging the likely consequences of removing the illegality defence from NHS bodies in claims by mental health patients who kill others. As the respondent submits, it does not seem likely that NHS staff or organisations need any encouragement to try to do their best to stop patients killing people.
  3.  The second is the policy of providing compensation to victims of torts where they are not significantly responsible for their conduct. It is not clear that there is any such general policy and the example of suicide cases which is relied upon raises different considerations, not least because suicide is not a crime.
  4.  The third is the policy of ensuring that public bodies pay compensation to those whom they have injured. This may be said to beg the question since it assumes that it was the respondent’s negligence which injured the appellant rather than her own criminal act. Even if it was, this is not one of those cases where the injury was the very thing which the respondent was engaged to prevent and it is agreed that the killing by the appellant of her mother could not have been predicted.
  5.  The fourth is the policy of ensuring that defendants in criminal trials receive sentences proportionate to their offending. That is consistent with the purpose of the narrower rule which is to avoid giving back with one hand what has been taken by the other.
  6.  I recognise that there is force in at least some of the policy considerations relied upon by the appellant, but I do not consider that they begin to outweigh those which support denial of the claim. In particular, as Gray makes clear, the resulting inconsistency in the law is such as to affect the integrity of the legal system. The underlying policy question identified in Patel is accordingly engaged. As stated by McLachlin J in Hall v Hebert [1993] 2 SCR 159 at 182, “concern for the integrity of the legal system trumps the concern that the defendant be responsible”.
(c) Stage (c) – Whether denial of the claim would be a proportionate response to the illegality, bearing in mind that punishment is for the criminal courts
  1.  It is not suggested that there were factors relevant to proportionality aside from the four factors identified by Lord Toulson at para 107 of his judgment in Patel, namely: (i) the seriousness of the conduct; (ii) the centrality of the conduct to the transaction; (iii) whether the conduct was intentional; and (iv) whether there was a marked disparity in the parties’ respective wrongdoing.
  2.  As to the seriousness of the conduct, this was a very serious offence. It involved culpable homicide committed with murderous intent. As was acknowledged on behalf of the appellant, unlawful killing is the most serious conduct imaginable. The appellant knew what she was doing and that it was legally and morally wrong.
  3.  As to the centrality of the conduct to the transaction, the offending is central to all heads of loss claimed and, as held in Gray, is the effective cause of such loss.
  4.  As to whether the conduct was intentional, there was intent to kill or to do grievous bodily harm. Whilst there may have been no significant personal responsibility, there was nevertheless murderous intent.
  5.  As to whether there was a marked disparity in the parties’ respective wrongdoing, the appellant was convicted of culpable homicide. Whilst she may not bear a significant degree of responsibility for what she did, she knew what she was doing and that it was morally and legally wrong. The respondent has admitted negligence in the appellant’s treatment. It is not the case, however, that the respondent’s staff did nothing in response to the appellant’s mental health relapse.
  6.  In all the circumstances I do not consider that denial of the claim would be disproportionate. It would be a proportionate response to the illegality, bearing in mind that punishment is for the criminal court. The same would apply to the materially similar facts of Gray, even more clearly in so far as the offending in that case involved significant personal responsibility. The fact that proportionality was not specifically addressed in Gray does not therefore undermine the approach taken or the decision reached in that case.
  7.  For all these reasons, the application of the trio of considerations approach set out in Patel does not lead to a different outcome.
(iv)      Conclusion on issue (2)
  1.  The appellant has not shown that Gray should be departed from and Clunis overruled. On the contrary, I consider that the decision in Gray should be affirmed as being “Patel compliant” – it is how Patel “plays out in that particular type of case”. The clearly stated public policy based rules set out in Gray should be applied and followed in comparable cases.
VIII    Issue (3) – Whether all heads of loss claimed are irrecoverable
  1.  In the appellant’s written case it was accepted that all heads of loss are irrecoverable pursuant to the ratio in Gray, save for (as was common ground) any losses for pain and suffering or loss of amenity that arose prior to the killing. The claim for general damages for loss of liberty was accepted as being barred by the narrower rule, the other heads by the wider rule.
  2.  In oral submissions there appeared to be some retreat from this position, although the only head of loss addressed in any detail was that relating to the Forfeiture Act.
  3.  In my judgment, the appellant’s concession was properly made. Damages for loss of liberty (head (ii)) and loss of amenity during her detention (part of head (iii)), are barred by the narrower rule. The other heads of loss are barred by the wider rule; indeed, two of them are expressly stated to be the consequence to the appellant of the killing of her mother (heads (i) and (iii)).
  4.  As to the Forfeiture Act claim, the reason that the appellant is unable to recover the full share of her mother’s estate is because an order to that effect was made by the court pursuant to the provisions of the Forfeiture Act. In deciding what order to make the court has regard to the conduct of the offender and of the deceased, to such other circumstances as appear to the court to be material and to the justice of the case. It would be entirely inappropriate to subvert the operation of the specific and bespoke Forfeiture Act regime, and the court order made thereunder, by permitting the appellant to recover from the respondent what she was not permitted to recover under the Forfeiture Act.
IX       Conclusion
  1.  For all the reasons outlined above, I consider that the appeal should be dismissed.