Previous: Voluntary manslaughter
Whereas voluntary manslaughter involves the same actus reus and mens rea as murder, but for some mitigating circumstance, involuntary manslaughter does not require an intent to kill, as was said by Baker in Glanville Williams’ Criminal law. In the words of Lord Atkin in Andrews v DPP , manslaughter is based on the “elusive” concept of unlawfulness as opposed to intent. There are three types of involuntary manslaughter: unlawful act manslaughter (sometimes called constructive manslaughter), gross negligence manslaughter and reckless manslaughter. In practice, the prosecution will decide which type of manslaughter it wishes to pursue, however, there is no obligation to do so.
The Law Commission has recommended the abolition of reckless manslaughter: a leftover from murder who only successful conviction occurred in R v Lidar . Hyam v DPP  made reference to this type of manslaughter, requiring serious injury to be highly probable. It is assumed that no unlawful act would (theoretically) be required. Due to its lack of authority and uncertainty, it shall not be discussed further.
Unlawful act manslaughter
Unlawful act manslaughter is the charge bought when a defendant has the actus reus of murder, but only the mens rea of a lesser offence (the unlawful act). Ashworth is very critical of the offence as it is a clear breach of the correspondence principle: a battery, which has a 6 month maximum sentence, could become a life sentence if the victim unexpectedly dies as a result of some unforeseen circumstances. R v Harvey  is a good example of this. Considering that some judges are critical of the GBH murder rule, it would seem just that others criticise this offence.
R v Goodfellow  summarised 4 separate components required to be proved in unlawful act manslaughter cases: the must be an intentional act; this act must be unlawful; it must also be dangerous and it must cause death. In Goodfellow, the defendant firebombed his own house in an attempt to show to the council that he was under threat. Three occupants died and Goodfellow was convicted of unlawful act manslaughter.
In R v Lamb , the court confirmed this requirement. A young boy killed his friend during experimentation with a revolver. He was unaware that the chamber of a revolver revolves when the trigger is pulled, such that a bullet was ‘lined up’ when he pulled the trigger. He was described as a fool only and was acquitted: has act was voluntary, but his unlawful act was unintentional.
If the act which causes death is lawful, there may be no unlawful act manslaughter conviction: in R v Scarlett , a landlord was legally entitled to use reasonable force to eject a patron from his pub. The death resulting from his act was not punishable in law. R v Lowe , notwithstanding its poor reasoning, appears to disallow unlawful act manslaughter by omission. However, the unlawful act must be a crime, and not a tort, according to Andrews v DPP , a case which dismissed negligence driving as being able to give rise to a conviction of unlawful act manslaughter. Finally, R v Andrews  also included strict liability offences within the definition of unlawful act.
It is for the jury to decide whether the unlawful (and intentional) act was dangerous. The test, outlined in DPP v Newbury and Jones  is the R v Church  test, an objective assessment of whether the defendant’s act might cause some harm. This harm need not be serious. R v Dawson  modified this test slightly, allowing account to be taken only of the knowledge of the defendant at the time: the jury could not account for the frailty of a victim’s heart in their objective test where the victim was in no physical danger and the defendant did not know of the frailty. Where the frailty of the victim is known, as it was in R v Watson , it could be said that in the objective test, it could be assumed that the reasonable man also knew of the frailty; although the dangerous act was not proved to be the cause of death so the conviction was quashed. R v Ball  distinguished R v Dawson  in part, holding that the reasonable man does not make mistaken beliefs, so perhaps actual knowledge on one hand and beliefs on the other can be distinguished from each other.
The ‘dangerousness’ need not be aimed at the victim, according to A-G Reference (No. 3 of 1994) , it must merely be capable of doing some harm to somebody; in this case an unborn baby. The unlawful act’s malice was transferred to an unborn child.
In R v Kennedy (No .2) , the supply of drugs did not cause death: death was caused by self-administration, rendering an unlawful act manslaughter conviction impossible. The unlawful act must be a substantial cause of death.
If the defendant’s act causes the victim to escape, and during that escape the victim is killed, the defendant will still be held to have caused death. In R v Carey , the victim ran away from gang threats and had a fatal heart attack. The threats were said not be unlawful and in any event, the escape was not provoked by them, but the principle is adequately conveyed. Conversely, in R v Bristow , the victim intervened in a burglary and was run over and killed when the defendants were escaping. The burglary was said to be continuing during the immediate escape and so an unlawful act manslaughter conviction was upheld.
If death is not an objectively foreseeable, an unlawful act manslaughter conviction will fail. According to R v M(J) , this foreseeability is a question of fact for the jury: the defendant did not know about the security guards health condition which caused an unforeseeable heart attack. Surprisingly, in R v Dhaliawal , the defendant was not charged with unlawful act manslaughter, as a recognised psychiatric (harm) was caused.
The Law Commission believes that unlawful act manslaughter is to harsh on defendants, saying in 1996 that a defendant being aware of the possibility of only some (minor) injury should not be enough to secure a manslaughter conviction. In a 2006 report, they suggested a replacement offence: criminal act manslaughter, which would require a criminal act intended to cause some injury, but also with an awareness of a serious risk of death.
Gross negligence manslaughter
The majority of the current law relating to gross negligence manslaughter is summarised in R v Adomako . Gross negligence manslaughter is an inherently uncertain offence in that it requires a lot from juries. To secure a conviction, the jury must first be convinced that a duty of care exists. The judge will decide whether there is enough evidence for the jury to find a duty. It is then for the jury to decide whether that duty was breached, and whether that breach was so serious that it should be labelled as a crime. This was said in R v Holloway , heard alongside R v Adomako .
In R v Bateman , it was said that where a negligent act goes beyond something which can be compensated in money (see the tort of negligence), it may be classed as criminal. Andrews v DPP  distinguished gross negligence as a middle ground between negligence and recklessness, although recklessness in this context has now been disregarded and is now explained with reference to an awareness of risk. Andrews v DPP  is however still good authority on the fact that dangerous driving is not enough to secure a gross negligence manslaughter conviction. Statutory offences should now be used instead.
Duty of care
R v Adomako  provides that a duty of care may be found whenever a positive act is undertaken, just as in the tort of negligence. According to R v Evans , it is for the judge to decide whether a duty of care exists, and such a duty may not be inferred exclusively from the principles of tort law. In R v Wacker , a duty was imposed on the grounds of public policy where the defendant failed to reopen a vent, causing the death of 58 illegal immigrants. In R v Willoughy , a conviction for gross negligence manslaughter resulting from arson was not quashed despite the lack of an apparent duty; the Court of Appeal considered the jury’s conviction as safe and affirmed that it is for the jury to decide whether a duty exists. In R v Sinclair , a duty was found out of friendship where a friend supplied drugs which caused death, and in R v Evans , a R v Miller  duty was imposed where one family member supplied drugs to another, perhaps in breach of the R v Rimmington  rule that old offences should not be reformed.
Breach of duty
R v Adomako  requires a jury to find a breach gross enough to be labelled as a crime for a gross negligence manslaughter conviction to be secured. According to R v Misra , there must have been a risk of death, and the apparently circular test for the jury to decide upon defines ‘crime’ as a moral standard only, and not a legal one, meaning that the standard does not breach defendants’ rights to a fair trial. It is not enough to say that the reasonable man would make the same mistake, according to R v Ball , although R v Dawson , which is applicable to both types of involuntary manslaughter, allows for the knowledge of the defendant to be accounted for.
Although R v Misra  tries to negate the circularity of the jury’s test, another criticism is the lack of a mens rea requirement. The Law Commission recommended in 1996 that a defendant be capable of perceiving a risk of death besides committing a gross breach of duty. This would then align the law relating to criminal damage with the law of manslaughter, as in R v G , where it was said that the two boys must have perceived the risk of damage to be convicted. The Law Commission reiterated this in 2006, although it has yet to be adopted.