Illegality Defence in Civil Claims | Lewis-Ranwell v G4S Health Services (UK) Ltd
The Supreme Court has recently been required, in the case of Lewis-Ranwell v G4S Health Services (UK) Ltd and others [2026] UKSC2, to confront the difficult legal question of whether the doctrine of illegality can bar a civil claim in negligence where the Claimant, though responsible for the killing of three men, was found not guilty by reason of insanity.
The Civil Court unanimously decided that the Claimant, Mr Lewis-Ranwell, was barred from bringing civil claims in negligence, which allegedly arose from circumstances connected to his mental health at the time of the murders, despite the fact that a ‘Not Guilty’ verdict had been returned in the Criminal Court.
The Claimant suffers from schizophrenia, a chronic mental disorder, and was originally diagnosed in his mid-twenties and occasionally admitted into hospital for psychiatric intensive care.
It was his contention that the Defendants in his civil proceedings, in which he alleged negligence, had failed to provide him with adequate mental health care and that, had such care been provided, it would have resulted in his admission to hospital, thereby placing him in a position in which he could not have committed the three murders.
Helen Holder of KANGS outlines the events which led to the Judgment of the Supreme Court.
The Circumstances
Shortly before the killings, the Claimant had on two separate occasions within twenty four hours, been arrested by the police on suspicion of separate offences. The first being that of burglary and the second, one of assault against an elderly man who he believed to be a paedophile.
During both periods of detention, he behaved erratically and violently and was attended to by mental health practitioners. Although the need for a mental health assessment was discussed, it was not undertaken and he was released on bail.
Just hours after his release from custody, in the course of a serious psychotic episode, the Claimant attacked and killed three elderly men in the delusional belief that they were paedophiles.
At his criminal trial, the Claimant was found to have carried out the killings but was found not guilty of murder by reason of insanity pursuant to Sections 5(1) and 5(3) of the Criminal Procedure (Insanity) Act 1964 which applies where:
‘a special verdict is returned that the accused is not guilty by reason of insanity.’
Effectively, it was accepted that whilst he was found guilty of carrying out the murders, he could not be held criminally responsible because of his insanity. He was committed to a secure hospital, where he continues to be detained.
The Civil Claim for Damages
Following the conclusion of the criminal proceedings and his detention in a secure hospital, the Claimant commenced civil proceedings against G4S Health Service (UK) Limited, Cornwall Police, Devon Partnership NHS Trust and Devon County Council, (‘the Defendants’). He alleged that they all negligently failed to provide him with appropriate medical treatment before the fatal attacks and that, but for this negligence, he would have been admitted to and detained in hospital, with the result that the killings could not have occurred.
The Defendants vehemently contested this claim, arguing it should be ‘struck out’ on the basis that it was barred by the defence of illegality, and commenced proceedings seeking the ‘strike out’ of the civil claim. In 2024, the Court of Appeal dismissed this Application, thereby allowing the claims in negligence to continue.
The Defendants appealed further to the Supreme Court.
What is the Defence of Illegality?
The defence of illegality, ex turpi causa, prevents any form of remedy where the claim is founded on the Claimants own serious wrong doing.
The full phrase ‘ex turpi causa non oritur actio’ translates as ‘no action arises from a dishonourable cause.’ The defence of illegality can be traced back to the case of Holman v Johnson (1775) 1 Cowp 341-343 where it was stated:
“No Court will lend its aid to a man who founds his cause of action upon an immoral or an illegal act.”
In Gray v Thames Trains [2009] 1 AC 1339 [30], Lord Hoffman stated:
“the maxim ex turpi causa expresses not so much a principle as a policy. Furthermore, that policy is not based upon a single justification but a group of reasons, which vary in different situations.”
In practise, those ‘situations’ considered by the court will include policy, proportionality and potential damage to the integrity of the legal system.
The Supreme Court’s Decision
The Supreme Court, decided that the Claimant’s claims were barred due to the illegality defence and, having regard to Patel v Mirza [2016] UKSC 42; [2017] AC 467, stated that:
- allowing the defendant to recover damages for his lawful detention and the consequences of the killings would undermine confidence in the legal system,
- the killing of three men was of the utmost seriousness and central to all heads of loss in the negligence claim. Refusing to allow the claim represents a proportionate response to the illegality,
- public policy considerations of maintaining the integrity of the legal system far outweigh those in favour of allowing the claim to continue.
The Supreme Court also reiterated that the Claimant’s Human Rights, namely Articles 3 and 8 were not engaged.
How Can We Assist?
The team at KANGS are committed to ensuring you receive strong, effective representation and that your rights are fully protected. We regularly act for clients facing allegations of serious criminal offences, including manslaughter, sexual offences, drug offences and grievous bodily harm amongst others.
We understand that being contacted by the police can be stressful, and often time-sensitive. Our team is available 24 hours a day, 7 days a week, to support you with police interviews, whether you have been detained or asked to attend on a voluntary basis.
If we can assist you, please contact our team using the details below. We would be pleased to hear from you.
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