Correct on the date of publication - 10 November 2025
Question:
What constitutes the offence of 'involuntary manslaughter'?
Answer:
In DPP v Newbury and Jones (1977) it was stated that cases of manslaughter might amount to little more than pure inadvertence and sometimes a little less than murder. Similar considerations were previously highlighted in R v Lipman (1969) when it was stated that:
'Manslaughter remains a most difficult offence to define because it arises in so many ways and, as the mental element, if any, required to establish it varies so widely, any general reference to mens rea is apt to mislead'.
Involuntary manslaughter might be defined as the unlawful killing of a person which does not amount to murder by reason of the offender having neither an intention to kill or cause grievous bodily harm or foresight that death was likely to result from his acts or omissions.
There are three main categories of involuntary manslaughter, these are manslaughter by an unlawful and dangerous act; manslaughter by gross negligence and corporate manslaughter (under Corporate Manslaughter Act 2007).
The law in respect of manslaughter by gross negligence was clarified by the House of Lords in the case of R v Adomako (1995) in which it was held that the elements of this category of involuntary manslaughter are -
2. breach of the duty of care towards the victim who dies;
3. the breach of duty caused the death of the victim; and
4. the breach of duty was such to be characterised as gross negligence and therefore a crime.
Duty of care
The case of Caparo (1990) set out the test for a duty of care:
2. whether the claimant was in an appropriate position of proximity to the defendant; and
3. whether it was fair and just to impose liability on the defendant.
Breach of duty of care
Sufficient care is required to be taken by an individual to discharge a duty of care placed on them, whether or not care has been taken is tested on an objective standard; the reasonable competent person conducting the same role as the defendant would have acted in the same manner. Should the test not be satisfied, a breach of duty of care can be satisfied.
Causation
The breach of duty of care must have caused the death. It does not have to be the only cause nor even the principal cause of death but it must have more than minimally, negligibly or trivially caused the death.
Should there be an omission to act, this must be a negligent failure to act which was a substantial cause of the death.
Gross negligence
In developing point 4 in Adomako's case it was held that -
(a) whether the defendant's breach of duty amounted to gross negligence depended on the seriousness of the breach of duty committed by the defendant in all the circumstances in which he was placed when it occurred; and
(b) whether, having regard to the risk of death involved, the conduct of the defendant was so bad in all the circumstances as to amount in the jury's judgement to a criminal act or omission.
Earlier legal authorities made reference to the accused acting 'recklessly' a word which has been subject to much judicial scrutiny and debate. In the Adomako case, it was held that in a manslaughter case founded on gross negligence, trial judges were entitled to use the word 'reckless'. The ordinary connotation of 'recklessness' will sometimes be relevant to assessing 'gross negligence'. In the case of Andrews v DPP (1937), it was stated -
'It is clear that indifference to an obvious risk and appreciation of such risk, coupled with a determination nevertheless to run it are both examples of recklessness. What the prosecution have to prove is a breach of duty in circumstances that the jury feel that the defendant's conduct can be properly described as reckless. That is to say a reckless disregard of danger to health and welfare of the deceased. Mere inadvertence is not enough. The defendant must have been proved to have been indifferent to an obvious risk of injury to health or actually to have foreseen the risk but to have determined to run it'.
Mere negligence would be insufficient to found a charge of involuntary manslaughter that was founded on negligence to perform a duty; a substantial degree of negligence must always be established (i.e. gross negligence).
Serious and obvious risk of death
In the case of R v Rudling (2016), it was held that where a charge of gross negligence manslaughter is based on an alleged omission, at the time of the breach of duty there must be a serious risk of death and not merely serious illness.
The case of R v Rose (2017) considered the meaning of ‘obvious’ and it was stated that:
“a mere possibility that an assessment might reveal something life-threatening is not the same as an obvious risk of death. An obvious risk is a present risk which is clear and unambiguous, not one which might become apparent on further investigation.”
At the time of the breach of duty of care, the reasonable person, in the same circumstances as the defendant, would foresee a serious and obvious risk of death.
