Lewis-Ranwell (Respondent) v G4S Health Services (UK) Ltd and others (Appellants) No 2

Case summary

Case ID

UKSC/2024/0040

Date published

21 January 2026

Parties

Appellant(s)

G4S Health Services (UK) Limited

Devon Partnership NHS Trust

Devon County Council

Respondent(s)

Alexander Lewis-Ranwell

Judgment appealed

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Judgment date

21 January 2026

Neutral citation

[2026] UKSC 2

Justices

Lord Reed

Lord Hodge

Lord Lloyd-Jones

Lady Rose

Lady Simler

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21 January 2026 

Lewis-Ranwell (Respondent) v G4S Health Services (UK) Ltd and others (Appellants)

[2026] UKSC 2

On appeal from [2024] EWCA Civ 138

Justices:

Lord Reed (President), Lord Hodge (Deputy President), Lord Lloyd-Jones, Lady Rose, Lady Simler

Background to the Appeal

The claimant, Mr Lewis-Ranwell, was charged with the murder of three men but found not guilty by reason of insanity. He now brings civil proceedings against the defendants to recover compensation for the consequences of these killings. The issue in this appeal is whether he is barred from bringing civil proceedings in negligence by the doctrine of illegality.

The claimant is diagnosed with schizophrenia. On 10 February 2019, the claimant attacked and killed three elderly men, Mr Anthony Payne, Mr Richard Carter and Mr Roger Carter, in their own homes. He did so in the course of a serious psychotic episode, under the delusional belief that they were paedophiles. He was arrested the following day after a further assault.

At his criminal trial, he was found not guilty of murder by reason of insanity. This means that it was accepted that he carried out the killings but was found not to be criminally responsible. In law, this plea is available if, due to mental disorder, the individual either did not know the nature of his acts or did not know that what he was doing was wrong. The claimant was detained at Broadmoor Hospital where he remains under a hospital order and a restriction order.

In the days before the killings, the claimant was arrested and detained on two occasions for a suspected burglary and an assault on an elderly man. During each detention, he behaved erratically and violently and appeared mentally very unwell. He was seen by mental health practitioners. The need for mental health assessments was discussed but not arranged before he was released on bail.

The claimant now brings a claim for compensation against the four defendants. G4S Health Services (UK) Limited, the first defendant, is a private company with responsibility for provision of forensic medical services to persons in custody. This responsibility was outsourced from the Chief Constable of Devon and Cornwall Police, the second defendant. Devon Partnership NHS Trust, the third defendant, was responsible for assessing people with mental illnesses in the criminal justice system. Devon County Council, the fourth defendant, was responsible for an emergency team of mental health practitioners who provided mental health assessments.

The claimant alleges that the four defendants were negligent in failing to provide him with adequate care or a mental health assessment. He alleges that, but for the alleged negligence, he would have been admitted to hospital and would not have killed the three men. Instead, he was released into the community in a psychotic state. He now seeks to recover damages for the consequences of the killings, including those arising from his compulsory detention, and an indemnity against any claims brought against him by the families of the men he killed.

The defendants, except the Chief Constable of Devon and Cornwall Police, issued applications to strike out the negligence claim on the ground that it is barred by the doctrine of illegality.

The trial judge dismissed the application, finding that the claim was not barred by the claimant’s illegal conduct and could proceed. The three defendants appealed to the Court of Appeal, which dismissed the appeal by a majority, with Andrews LJ dissenting. The three defendants now appeal to the Supreme Court.

Judgment

The Supreme Court unanimously allows the appeal. The Supreme Court holds that the claimant is barred by the doctrine of illegality from bringing civil proceedings in negligence to recover compensation for the consequences of the killings. Lord Hodge and Lord Lloyd-Jones give the judgment, with which Lord Reed, Lady Rose and Lady Simler agree.

Reasons for the Judgment

i) The threshold question

The first issue is whether the act in question, the killing of the three men, engages the illegality defence [112]. A threshold is needed because it would be unjust if trivial acts of unlawfulness barred otherwise valid legal claims [113]. The actions of the claimant do not have to carry criminal responsibility, however, to cross the threshold [114]. The acts must engage the public interest, and the underlying rationale of the defence is the coherence of the law by not rewarding illegal conduct [118-119].

There is no direct authority in this jurisdiction on the precise question before the court and therefore the court must develop principles established in earlier cases on a step-by-step basis [120]. The most similar previous cases involved criminal convictions, where the defence of diminished responsibility applied. This is a partial defence which reduces a conviction of murder to manslaughter, when the individual’s mental state was substantially impaired by a medical condition. By contrast, the claimant in this case was found not guilty by reason of insanity, which is a full defence resulting in an acquittal. However, the fact that the claimant was not convicted of a criminal offence should not be a decisive consideration [122].

The distinction between the defences of diminished responsibility and insanity in the criminal law should not govern the availability of the illegality defence in civil law for several reasons. First, the criminal law regarding the defence of insanity is criticised as being out of date [123]. Secondly, the criminal law necessarily sets out clear dividing lines between conduct which results in criminal responsibility and conduct which does not, but it is not appropriate for the civil law to rely on the same distinctions [124]-[125]. Thirdly, the difference between those who are criminally responsible for their acts, notwithstanding their diminished responsibility, and those who are not because they do not know that what they are doing is wrong, is a difference between positions on a spectrum of mental illness. The difference between the cases is one of degree rather than a clear distinction [126]-[127].

This difference has no bearing on the coherence of the law which is of central importance [127]. Even though there was no finding of criminal responsibility, the jury’s verdict established that the claimant did kill the three men [128]. Killing a human being without lawful justification breaches the most fundamental moral rule in our society: you shall not kill. This is true even when the person bears no criminal responsibility for his actions [134]. The hospital order with restrictions, for which the claimant seeks to recover compensation, was necessary to protect the public from the claimant [131]. The claimant’s actions demonstrated the danger he posed to the public and accordingly affect the public interest [131]. Therefore, the killing of the three men is unlawful conduct which engages the illegality defence [134].

ii) Assessment of whether the defence should apply to the present case

The next issue is whether the defence should apply to the present case based on the trio of considerations set out in Patel v Mirza [2016] UKSC 42; [2017] AC 467 [135]. These are a) the underlying purpose of the prohibition which has been transgressed and whether that purpose is furthered by denial of the civil claim, b) any other relevant public policy on which denial of the claim will have an impact, and c) whether denial of the claim would be a proportionate response to the illegality [136]-[138].

a) The purpose of the prohibition

The prohibition breached by the claimant’s acts in killing the three men is the most fundamental rule that you shall not kill. Its purpose is the preservation of life. The law seeks to protect the public and deter unlawful killing. It also seeks to condemn publicly and punish those who kill unlawfully and to acknowledge the wrong done to the victims [141].

This prohibition applies with equal force to an individual found not guilty of murder by reason of insanity. The claimant’s conduct is not justified or excused because he is spared criminal responsibility [142]. Examined broadly there may be some deterrent effect in a clear rule that unlawful killing never pays [143].

Allowing the civil claim to proceed would give rise to a series of inconsistencies which would damage the integrity of the legal system [144]-[151]. For example, the judge was required by the jury’s verdict to make a hospital order and restriction order to protect the public. It would be inconsistent for a civil court to order payment of compensation to the claimant for the consequences of lawful detention ordered by a criminal court [145]. Public confidence in the legal system would be undermined by these inconsistencies [151]. These are weighty considerations which support the view that the underlying purpose of the prohibition transgressed by the claimant would be enhanced by denying his civil claim [153].

b) Other relevant public policies

In general, it is in the public interest that courts should adjudicate civil wrongs [155]. While allowing the civil claim would enable examination of what may have gone wrong, there are alternative procedures, such as inquests and public inquiries, which are better suited for that purpose [156]. The policy considerations in favour of maintaining the integrity of the legal system greatly outweigh those in favour of permitting a claim [159].

c) Proportionality of denying a civil claim

This stage of the analysis engages more closely with the specific facts of the individual case [160]. In this case, the acts in question, killing three men, are of the utmost seriousness and they are central to all heads of loss claimed in the civil claim [161]. Therefore, denying the claim is a proportionate response to the illegality [162].

References in square brackets are to paragraphs in the judgment.

NOTE:

This summary is provided to assist in understanding the Court’s decision. It does not form part of the reasons for the decision. The full judgment of the Court is the only authoritative document. Judgments are public documents and are available at: Decided cases - The Supreme Court