Newsletters Criminal Defence 2nd Nov 2020

R v Broughton Clarifying Causation in Gross Negligence Manslaughter


In 2017 a 24-year-old woman, Louella Fletcher Michie, died at the Bestival Music Festival, having taken 2-CP, a Class A drug, supplied by her boyfriend, the appellant.

The Prosecution’s case was that having supplied the drug and remained with her, the appellant owed Louella a duty of care to secure medical assistance as her condition deteriorated to the point where her life was obviously in danger.  He was said to have been grossly negligent in failing to obtain timely medical assistance, which was a substantial cause of her death.

The sole evidence relating to causation came from Professor Deakin, a Prosecution expert witness.  His evidence was that had Louella received medical assistance prior to 9.10 PM, there was a 90% chance that she would have survived.

In overturning the appellant’s conviction on appeal, a very strong Court of Appeal held that the case should have been withdrawn from the jury at the close of the Prosecution’s case as had been submitted at trial.  The Prosecution evidence could not, said the Court, prove to the criminal standard that with medical intervention as soon as possible after Louella’s condition presented a serious and obvious risk of death, she would have survived (emphasis added).

The Court rejected the Prosecution’s contention that a jury could find a defendant guilty of gross negligence manslaughter where their negligence had deprived a person of “a significant or substantial chance of survival”, available to them at the point of the defendant’s negligence.

The case and the decision on appeal attracted widespread media attention as had Louella’s death at the time.  Whilst the decision does not change the law in relation to causation, it provides important clarity.  It should, therefore, be regarded as the leading authority on causation in the context of gross negligence manslaughter, including cases involving medical professionals.

The case provides useful guidance on the temporal relationship between key elements of gross negligence manslaughter, the distinction between scientific and legal certainty, and, on when issues of causation may properly be withdrawn from a jury.


The Six Elements of Gross Negligence Manslaughter

In reviewing the key authorities in relation to gross negligence manslaughter, the Court identified six elements that the Prosecution must prove before a defendant can be convicted of gross negligence manslaughter (para. 5):

  1. “The defendant owed an existing duty of care to the victim.
  2. The defendant negligently breached that duty of care.
  3. At the time of the breach there was a serious and obvious risk of death. Serious, in this context, qualifies the nature of the risk of death as something much more than minimal or remote.  Risk of injury or illness, even serious injury or illness, is not enough.  An obvious risk is one that is present, clear, and unambiguous.  It is immediately apparent, striking and glaring rather than something that might become apparent on further investigation.
  4. It was reasonably foreseeable at the time of the breach of the duty that the breach gave rise to a serious and obvious risk of death.
  5. The breach of the duty caused or made a significant (i.e. more than minimal) contribution to the death of the victim.
  6. In the view of the jury, the circumstances of the breach were truly exceptionally bad and so reprehensible as to justify the conclusion that it amounted to gross negligence and required criminal sanction.”



The primary focus on appeal was causation.  The Single Judge had given leave on one ground, namely that the Prosecution had failed to adduce evidence from which the jury could be sure that the appellant’s negligence was a cause of Louella’s death.

The Defence argued (set out at para. 8) that in a case concerning a negligent lack of medical attention, to establish that the breach of duty (here, the failure to obtain medical help) was a substantial cause of death, the Prosecution must prove to the criminal standard that the person concerned “would have lived”.

The Prosecution argued (set out at para. 9) that a different test should apply.  They submitted that the correct test was whether the jury could be sure that the defendant’s negligence deprived the victim of “a significant or substantial chance of survival that was otherwise available to the victim at the time of the defendant’s negligence”.

The Prosecution submitted (set out at para. 11) that requiring proof of certainty of survival would render many cases where death had ensued after gross negligence, medical or otherwise, “impossible to prosecute” because of the difficulty in proving to the criminal standard that there was no possibility that the person still would have died after treatment.



Causation and Proof that the Person Would Have Survived

In allowing the appeal, the Court of Appeal provided important clarification in relation to the test for causation in gross negligence manslaughter cases.  Rejecting the Prosecution proposition that negligence depriving someone of a “significant or substantial” chance of survival was sufficient, the Court ruled that the key question in such cases was whether medical attention would have saved the person’s life.

The Court found (para. 102) that the expert’s opinion that medical intervention at 9.10 PM would have given Louella a 90% chance of survival left a “realistic possibility that she would not have lived”.


A Temporal Connection Between the Elements

Beyond the central dicta concerning causation, the decision also provides useful guidance in relation to other aspects of gross negligence manslaughter.

For example, the case highlighted the temporal relationship between three core elements of gross negligence manslaughter in cases such as this.

In summary, (and in line with discussion at para. 89), the Prosecution in Broughton had to establish:

  1. That at some point, Louella’s condition was such that there was “a serious and obvious risk of death”,
  2. That at that point, the appellant was grossly negligent in failing to obtain medical assistance for her, and, that
  3. At that point, such medical assistance would have saved her life.

In this context, the Court emphasised the need for:

“a clear focus on when the condition of the deceased reached the threshold of serious and obvious risk of death, what the accused should have done then and the prospects of survival at that point”.


The Distinction Between Legal and Scientific Certainty

The decision also highlighted the need for caution in conflating the conclusions of an expert with the function of a jury.  At paragraph 100, the Court of Appeal held:

“It is unhelpful to attempt to contrast scientific certainty (put at 100%) with a different figure for legal certainty.  Human beings asked the question whether they are sure of something do not think in those terms”.

The Court therefore decisively rejected the conflation of scientific certainty and legal certainty, or, as counsel for the Prosecution on appeal described it,

“the impossibility of transposing the percentages expressed in medical opinion into the standards that a jury might equate with being sure”.

However, and somewhat ironically, in determining that a 90% chance of survival meant that a jury could not be “sure”, it is possible to envision a scenario in which the decision is in fact cited in support of the proposition that there is a percentage below which the jury cannot be “sure”.

Despite this, it is clear that Courts deciding cases in line with Broughton are unlikely to entertain suggestions that a percentage can or should ever be applied to the concept of legal certainty.


Withdrawing Causation from the Jury

Broughton also provides useful guidance in relation to when issues relating to causation should be left to or withdrawn from a jury.

In essence the Court held that where, when considering the evidence in its totality, a jury could not be sure of causation, the case should be withdrawn from them.  However, it was also made clear that this will be rare, and is unlikely where there is evidence before a jury relating to causation that goes beyond a single expert’s opinion.

In support of the trial judge’s decision to refuse the Defence’s submission at the close of the Prosecution case, the Prosecution cited R v. Misra [2004] EWCA Crim 2375 (a medical case) in which, similarly, an expert had provided a variety of descriptors of the chances of survival.  In Misra, Judge LJ (as he then was) said (para. 22):

“In our judgment the submission that there was no case to answer on the causation issue was untenable…The causation issue was entirely for the jury. If the submission was upheld, the judge would have usurped its function”.

In response, the Defence in Broughton argued (para 73) that the suggestion that causation was an issue entirely for the jury, “presupposed that that there was evidence which would enable a jury to be sure”.

The Court of Appeal in Broughton did not depart from Misra but rather distinguished it, noting (para. 103):

“this is one of those rare cases … where the expert evidence was all that the jury had to assist them in answering the question on causation.  That expert evidence was not capable of establishing causation to the criminal standard.  [Prosecution counsel’s] final submission that at 21.10 Louella was deprived of a 90% chance of survival was an accurate reflection of Professor Deakin’s evidence but, for the reasons we have explained, that is not enough”.

The decision in Broughton does not represent a departure from previous authorities but rather provides important clarification and guidance in what can be a confusing and nuanced area of the law for jurors and practitioners alike.


Brian O’Neill QC and Grace Forbes

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