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Investigative police failings remain open to attack

The Supreme Court has today dismissed unanimously the Commissioner’s appeal against the imposition on the police of a positive duty to conduct…

Commissioner of Police of the Metropolis v DSD and another

Supreme Court (Lord Neuberger, Lady Hale, Lords Mance, Kerr and Hughes) - UKSC 2015/0166 - 21 February 2018

Executive summary

In a decision with far-reaching implications for the police service, the Supreme Court has today dismissed unanimously the Commissioner’s appeal against the imposition on the police of a positive duty, arising under Article 3 of the European Convention on Human Rights - prohibition of torture and inhuman or degrading treatment - to conduct effective investigations into allegations of such ill-treatment.

Background and facts

This well-known lead case concerns claims for declarations and damages brought by two victims of the infamous “black cab rapist” John Worboys, who between 2002 and 2008 committed in excess of 100 rapes and sexual assaults on women passengers. Worboys targeted single females with drugs and alcohol to incapacitate them so he could assault them. Many victims did not report those crimes and because of the drugs and alcohol used by Worboys many who did had only partial recollections of events.

Worboys was eventually convicted on 12 March 2009 of one count of rape, five sexual assaults, one attempted assault and 12 drugging charges, committed between July 2007 and February 2008. His current proposed release from custody has been the subject of recent challenge and attendant widespread publicity.

The police investigation was subject to extensive review by the Independent Police Complaints Commission (IPCC) and the Metropolitan Police itself.  A number of individual and systemic failings were identified.

DSM was one of Worboys’ first victims in May 2002 and NBV one of the last in 2007. Their test cases represent the claims of other victims who sit within the spectrum of Worboys’ serial offending.

This appeal follows the Court of Appeal decision in June 2015 (click here for our legal update) upholding the first instance liability decision of Green J. The present state of the law, challenged by the Commissioner in this appeal, imposes on the police (as an embodiment of the state) a positive duty under Article 3 (prohibition of torture and inhuman or degrading treatment) to investigate effectively qualifying crimes committed by non-state persons, to ensure the protection of persons from ill-treatment of the gravity contemplated by Article 3.


The appeal was dismissed unanimously. Lord Kerr delivered the lead judgment (Lady Hale agreeing), with Lord Neuberger giving his own judgment agreeing with Lord Kerr (Lady Hale again agreeing). Lords Mance and Hughes gave separate judgments with differing reasoning. Readers are referred to the judgment (click here for link) for the detailed discussion and reasoning on the important points arising in this case.

The main issues for the Supreme Court were –

  1. Is the general duty to investigate ill-treatment under Article 3 owed to the public or individual victims?
  2. Is the duty a systems or operational duty?
  3. Is the duty confined only to Article3 breaches in which the state is itself complicit?
  4. If not, does breach of the duty give rise to an entitlement to compensation against the state?
  5. Does the availability of claims against the offender or under CICA scheme bear on that?
  6. Is the refusal of the common law to recognise a duty of care on the police in the prevention or investigation of crime relevant to the Article 3 question?
  7. Are ECtHR decisions in this area clear that the duty in question arises?

Addressing those questions compendiously, Lord Kerr concluded that the state is obliged under Article 3 to conduct an effective investigation into crimes involving serious violence, whether by state agents or individual criminals. For the protective right to be practical and effective, breach of that investigative duty gives rise to a right to compensation against the state.

After taking issue with Lord Hughes’ view that only systemic or structural failures, and not operational fallings, are caught by the investigative duty, Lord Kerr dismissed the notion that the decision in the present case would open the floodgates:

“The recognition that really serious operational failures by police in the investigation of offences can give rise to a breach of article 3 cannot realistically be said to herald an avalanche of claims for every retrospectively detected error in police investigations of minor crime.” (paragraph 53)

As to compensation, the distinction between the aims of common law compensation and an award to signal the importance of the state’s discharge of its obligations was noted. In the present case, nothing in the approach of the courts below was flawed in the award of compensation.

As to the difference in approach to potential liability at common law and under Article 3, Lord Kerr observed (in disagreement with Lord Hughes) that carrying out police investigations would not so much divert resources as lead to more effective investigations, enhanced standards and saved resources:

“There is no reason to suppose that the existence of a right under article 3 to call to account egregious errors on the part of the police in the investigation of serious crime would do other than act as an incentive to avoid those errors and to deter, indeed eliminate, the making of such grievous mistakes.” (paragraph 71)

But in words of some potential comfort to the police, Lord Kerr then went on to state that:

only obvious and significant shortcomings in the conduct of the police and prosecutorial investigation will give rise to the possibility of a claim.” (paragraph 72)

Lord Neuberger agreed that serious and purely operational failures were sufficient to infringe the investigative duty, that view being supported by the Strasbourg cases. As to the difference between the common law and human rights’ approaches, he further noted that just as the domestic tortious test for liability had not been widened to match the human rights’ test, neither should the latter be narrowed to meet the former.

The concluding judgment of Lord Mance is also informative. He concludes that the distinction between operational and systemic failures has been replaced by a distinction between simple errors or isolated omissions and more serious failings. Only the latter give rise to challenge.


Notwithstanding the caveat that only ‘obvious and significant shortcomings’ and ‘serious failings’ are likely to support successful challenges to police failings in the investigation of qualifying crimes, an increase in the number of prospective claims seems inevitable. At a time of continuing and considerable funding pressures on the police service, whether investigators will be able to respond in the positive manner suggested by the Supreme Court must remain to be seen.

If you have any questions or would like more information on our legal update, please contact Nick Peel.

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