Supreme Court Downgrades Evidential Standard of Proof for Unlawful Killings

By Fatima Mumtaz

This article looks at the landmark judgment of R (Maughan) v HM Senior Coroner for Oxfordshire [2020] on Coroner inquiries concerning unlawful killings.

Unlawful killing can be classified under two offences. These are:

  1. Murder: defined as the unlawful killing of a human being under the Queen's peace with the intention to kill or cause Grevious Bodily Harm (GBH); or

  2. Manslaughter: defined as either voluntary or involuntary.

Both offences can carry life sentences.

Involuntary manslaughter can be subclassified in two other offences:

  1. Unlawful act manslaughter, in which the victim dies as a cause of the defendant’s actions where a reasonable person would have realised the physical harm which such action posed to the victim, e.g. “one-punch” manslaughter;

  2. And manslaughter by gross negligence, in which a breach of duty of care owed by the perpetrator caused the victim’s death.

Voluntary manslaughter possesses all the elements of murder, however the offence is characterised by a lack of intent or provides for statutory partial defences, such as those of diminished responsibility or loss of control (formerly provocation). This can be found in sections 52-56 of the Coroners and Justice Act 2009.

A further form of manslaughter exists, called corporate manslaughter, which is laid out in s1 of the Corporate Manslaughter and Corporate Homicide Act 2007, applying to organisations. As a result of whom this offence applies to, the only sentence which can be imposed on the perpetrator is a fine, which sometimes runs to millions of pounds. It must be proved that the substantial element of the breach was due to how the organisation’s activities were managed or organised by its senior management.

The final offence found under manslaughter is that of Infanticide, whose provisions are set out in s1 of the Infanticide Act 1938 (as amended by section 57, Coroners and Justice Act 2009). This covers instances where a woman is charged with the murder or manslaughter of her child.

All the aforementioned offences were previously held to the stringent criminal standard of proving beyond a reasonable doubt. This means that a jury or Coroner had to be convinced that all elements of the crime had been satisfied beyond a reasonable doubt.

On the 13th November 2020, the Supreme Court, by a majority of 3:2 in R (on the application of Maughan) v Her Majesty’s Senior Coroner for Oxfordshire [2020] UKSC 46, ruled that the standard of proof at inquest for unlawful killing determinations is on the balance of probabilities - same as suicides. The court upheld the decision of the Divisional Court and the Court of Appeal.

Therefore, evidence to support a short form conclusion of lawful killing, unlawful killing, or suicide, is now subject to a less strict, civil standard.

In this case, Lady Arden (on behalf of the majority) held that this decision was reached after having taken into consideration a series of factors, which could influence the number of claims made under the old law. Among these factors were the facts that: inquests were civil proceedings; the higher standard of culpability under the old caselaw could contribute to under-recording of suicides; societal attitudes have shifted towards suicide and the fact that developed inquests are sufficiently adept to sufficiently determine facts.

As a result of R (on the application of Maughan), a Coroner/jury must now establish:

  1. The existence of a duty of care,

  2. A breach of that duty of care,

  3. The risk of death (not just serious injury) was a reasonably foreseeable consequence of misconduct,

  4. Breach caused death,

  5. Having regard to the risk, the misconduct was grossly negligent so as to be condemned as a serious crime of manslaughter.


The decision invokes profound implications on the inquests procedure for both sides.

As the hurdle to prove culpability to a higher threshold has now been eliminated, it is more likely that ‘unlawful killing’ conclusions will be reached in greater numbers. For example, bereaved families of the deceased victim looking for answers, will see this as an opportunity to obtain justice and pursue unlawful killing verdicts.

Inference of blame will be easier to achieve, and this could escalate confrontations in many health and safety cases.

On the other hand, organisations and employers involved in inquests of fatalities will be more likely to face lengthy investigations and be declared guilty. This is because there is a lower threshold to be crossed to prove liability, causing greater financial and reputational damage than under the old case law. Consequently, such individuals may adopt a more robust approach in working policies to avoid facing trial.


Current practice dictates that an unlawful killing case is referred to the Director of Public Prosecutions, the police, and CPS, who decide whether there is sufficient evidence to bring a prosecution and whether it is in the public’s interest to do so. However, there is now potential for the police/CPS to conclude that a case has insufficient evidence to pursue a manslaughter claim, which would lead the police and CPS to send the case to inquest, where a Coroner or jury may decide otherwise.

Subsequently, the case would be referred back to the police (post-inquest) for a second criminal investigation to determine other charges.


The Supreme Court appears to have taken the view that a lower evidential burden of proof is appropriate because the legal consequences of inquests are so limited. Nonetheless, one should also consider the practical and reputational damages flowing from such a guilty verdict.

Defendants may be able to more easily influence Coroners through their ‘narrative verdicts’ (their description of events leading to death, without blame or label).

It is clear that Coroners will be under heavy-pressure to arrive at fair and just decisions. Inquests are fact-finding inquiries and the full effects of this change in the law are yet to be assessed.

Only time will tell whether they will be inclined and more assertive to adjourn inquests in favour of further investigations or adopt another approach.