The duty to warn non-patients

Griffiths v The Chief Constable of the Suffolk Police and Norfolk and Suffolk NHS Foundation Trust [10.10.18]

This case considered the scope of the duty of care owed by healthcare professionals to non-patients, confirming that it would only arise in the most novel of cases. In addition, this case shines a light on the potential for future claims to be made against NHS Trusts, under the Human Rights Act 1998 (HRA).


The tragic circumstances of this case arise out of the murder of MG by John McFarlane on 6 May 2009. Mr McFarlane had been a long-term mental health patient at the Norfolk and Suffolk NHS Foundation Trust (Trust), with a history of depression, suicidal thoughts and an underlying possible psychosis.

Mr McFarlane became friends with MG in 2008 and soon became infatuated by her, leaving his wife in the hope of pursuing a romantic relationship with MG. On 2 May 2009, MG made it clear that she did not see their relationship becoming romantic. Mr McFarlane became distraught and attempted suicide, but was stopped and taken to the Trust on 3 May 2009. A Mental Health Act Assessment (MHA) was undertaken and it was concluded that he did not meet the criteria for detention.

On 5 May 2009, MG called the police frightened by Mr McFarlane’s behaviour. On 6 May 2009, he killed MG in front of her children. He then made an attempt to end his own life, but was stopped. At his criminal trial, he pleaded guilty to murder and was sentenced to life imprisonment.

The civil claim was brought against the NHS Trust by MG’s three children in negligence, on her behalf, and as victims in their own right, and as a claim for damages under the HRA.

Negligence claim

The allegations were that the Trust owed a duty to Mr McFarlane to perform the MHA assessment to a reasonable standard and, had it done so, the Trust would have detained him, preventing the murder. In addition, it was alleged the Trust owed a direct duty to MG to warn her of the risk that their patient posed to her life. Both allegations were dismissed.

In reaching their decision, the court confirmed that no breach of duty to a secondary victim could arise without the claimant first establishing a breach of duty to the patient, the primary victim.

The duty to warn

The court confirmed that only in exceptional instances will a duty to warn be imposed.
Firstly, if the defendant assumes a positive responsibility to safeguard the claimant and it would be fair, just and reasonable. Such circumstances would arise if the psychiatrists foresaw, or should have foreseen, a risk their patient would murder or seriously assault another. In reaching his decision, Mr Justice Ouseley emphasised the importance of patient confidentiality and that any risk to a non-patient must be so significant for this to be outweighed.

The other exception would be if three factors were satisfied:

  1. A position of control over the patient. It does not need to amount to physical control but whether the Trust could have taken steps to prevent the harm. Ouseley J confirmed this would be satisfied if the potential victim had been warned of the harm.
  2. Reasonable foreseeability that there was a sufficient risk of harm, one which the potential victim was particularly vulnerable to. Ouseley J concluded that this was not satisfied in this case. Mr McFarlane had made no threats or expressed an intent to harm MG, and he did not have a history of violence or aggression to others. The fact that he was a suicide risk could not lead a reasonable practitioner to conclude that he posed a serious risk to MG.
  3. Special relationship between the defendant and potential victim. For this, the potential victim needs to be sufficiently identifiable from general members of the public and that there was a clearly apparent risk to that individual.

Human rights claim

The HRA claim asserted that the Trust had breached their duty as:

  • There was a real and immediate threat to his life through suicide (operational duty to the patient)
  • There was a real and immediate risk of ill-treatment to another (duty to the non-patient)
  • There was an obligation to provide protection to society against violent acts of a patient (public obligation).

The human rights claim was unorthodox and appeared doomed to fail. In dismissing these allegations, Ouseley J reaffirmed the now well-established legal principles, as set out in Osman and Rabone.

That aside, this case does show the likely trajectory of future decisions, arising from a claim made under the HRA. The importance of patient autonomy arose repeatedly and was a central factor in considering whether an operational duty was owed if the patient lacks capacity to make an autonomous decision to take their own life.

This could lead to the very real possibility that a duty might apply to a community mental health patient, who has refused voluntary admission and cannot be detained under statute. No detail was provided as to the circumstances in which this would arise, but may lead to claims posing interesting questions as to whether mental health Trusts can actually satisfy an operational duty when unable to detain patients where powers are not available to them.


The duty to warn a potential victim has always been a stringent test, but this case clarifies that NHS Trusts will only incur liability to non-patients in the rarest and most novel of cases. Doctor-patient confidentiality is a paramount factor and the duty to warn will only be imposed where the risk of harm is so serious that it would be in the public interest to do so.

An interesting development from this case were allegations made under the HRA and the emphasis on patient autonomy. This certainly appears to be the direction of travel, but it remains to be seen how this affects the field. In particular, it is not yet clear how the courts will reconcile autonomy with the draconian powers available under the MHA and the rigorous duties owed by Trusts to their patients where the MHA is engaged.

Related item: ‘Extension’ to the duty of care in healthcare