Involuntary Manslaughter

What is involuntary manslaughter?

Involuntary manslaughter is when an unlawful act causes death, or when a death is caused by an act of gross (criminal) negligence.  Manslaughter which occurs following the commission of an unlawful act is also known as constructive manslaughter.

Constructive manslaughter

Constructive manslaughter has three elements, namely:

  1. An unlawful act committed by the defendant which results in the death of another person

  2. The act must have involved a risk that someone would be harmed

  3. The defendant must have had the mens rea for the unlawful act which led to the victim’s death

Unlawful act committed by the defendant which causes the death of another person

Much of the case law in this area has involved drug users and people assisting them with taking drugs, though there have been instances before the courts where drug dealers have not been liable for deaths caused by the drugs they have supplied (see, for example, R v Dalby [1982]).  An important point to consider is the chain of causation between the unlawful act and the subsequent death.  Liability will likely be established if there is little or no break in this chain.  In R v Kennedy [1999] the victim had asked the defendant to get him something to help him sleep.  The defendant gave the victim a syringe of heroin.  The victim injected himself with the heroin and was dead within the hour.  The defendant was convicted of manslaughter.  The case can be compared with R v Rogers (Stephen) [2003] where the defendant held a tourniquet around the victim’s arm so that the victim could inject themselves.  The Court of Appeal upheld the defendant’s conviction for manslaughter stating that the defendant had been sufficiently involved in the injection to make him guilty of manslaughter when the victim later died.  The Court of Appeal did question the Kennedy decision when considering the Rogers case, but did not overrule it.    

The act must have involved a risk that somebody would be harmed

An objective test is used to determine the risk.  In other words, would a reasonable and sober person who is watching the act identify a risk?  Additionally, the harm caused must be physical, which includes shock.  Psychological or emotional harm is insufficient.  The case law has established that there must be an unlawful act that was dangerous in the sense that a reasonable and sober person would recognise that the act was enough to put the victim at risk of physical harm.  In R v Carey, C and F [2006] it was held that when deciding whether an act is dangerous, knowledge of the victim’s nature could be relevant.  A reasonable and sober person, unaware that an apparently healthy teenage girl in reality had a congenital heart defect, would probably not reach the conclusion that an unlawful act which amounts to an affray would result in the girl’s death from heart problems. 

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For more information on:

  • The defendant must have had the mens rea for the unlawful act which led to the victim’s death
  • Manslaughter by gross negligence