Involuntary Manslaughter (Part 1).

So today, we are going to be discussing involuntary manslaughter. This essay is a continuation of my series on homicide, where I’ve reviewed murder in detail, and then voluntary manslaughter, and now we’re on to involuntary manslaughter. Essentially we are working our way down regarding the seriousness of crimes.

So let’s start by recapping our understanding of both murder and voluntary manslaughter.

It is important to note that the guilty act or the Actus Reus (AR) is the same for all types of homicide. The defendant caused the death of the victim.

Murder is the unlawful killing of another person with the intent to kill or cause serious injury. This means that the defendant must have intended to cause the death of the victim or intended to cause serious injury to the victim and was aware that their actions could result in the victim’s death. This carries a mandatory life sentence.

Voluntary Manslaughter is where there is a successful partial defence that lowers the level of culpability of the defendant. The defence of loss of control can be used if the defendant was provoked into killing the victim, and their actions resulted from that provocation. For this defence to be successful, the provocation must have been sufficient to cause an ordinary person to lose self-control and act on impulse.

The defence of diminished responsibility can be used if the defendant suffered from a mental disorder that significantly impaired their ability to understand the wrongfulness of their actions. For this defence to be successful, the defendant must have suffered from a qualifying mental disorder at the time of the offence.

Involuntary manslaughter is a type of homicide committed unintentionally as a result of the defendant’s criminal conduct or gross negligence. It is the accidental killing of another person, not a killing that was intentional or planned.

So the AR is the same as Murder, but no MR exists. This is the key difference. This lack of MR, of intent to kill another human being, is what is referred to when we say “involuntary’.

In everyday English, “involuntary” means something done without intent or willingness. But in the term “involuntary manslaughter,” it refers to the fact that the victim’s death was not intended by the defendant, not that they could not help themselves from carrying out the actions.

To understand involuntary manslaughter, remember that the offender did not mean to kill or cause serious bodily harm (which would be murder or voluntary manslaughter). However, they were responsible for the death in some way and the state considered this to be a criminal act.

Involuntary manslaughter is subcategorized into three different types, two of which we are going to review today:

  • Unlawful Dangerous Act Manslaughter (UDAM): This type of involuntary manslaughter occurs when the defendant commits a criminal offense (such as shoplifting, robbery, or arson), and this offense leads to the death of another person. For example, if an individual burns down their office to claim insurance, and kills someone inside that they were unaware was there, they may be charged with UDAM.
  • Gross Negligence Manslaughter (GNM): This type of involuntary manslaughter occurs when the defendant’s actions show a high degree of negligence or recklessness, and this negligence or recklessness causes the death of another person. For example, if a driver is texting while driving and runs over a pedestrian, causing their death, they may be charged with GNM.

There are some valid criticisms with regards to Involuntary Manslaughter. Throughout the years, experienced judges have faced difficulty in determining when an individual should be held accountable for the unintentional killing of another person. This has caused discrepancies and contradictions.

In cases of involuntary manslaughter, often the last thing that the wrongdoer desired was the death of another person. Thus, involuntary manslaughter is considered to be less serious than murder or voluntary manslaughter. The penalty imposed by a court is often an indication of the seriousness of an offence and how blameworthy or culpable the offender is viewed to be. People can have very different views about what punishment would fit the crime.

The distinction between involuntary manslaughter and murder can be a difficult one to make, as it often relies on the intent of the person who caused the death. However, intent can be difficult to prove and may be interpreted differently by different judges or juries. This can lead to inconsistency in the way that these offenses are charged and punished. For example, one judge or jury may view a person’s actions as being reckless and deserving of a charge of involuntary manslaughter, while another judge or jury may view the same actions as being intentional and deserving of a charge of murder.


Some people argue that the punishments for involuntary manslaughter are not severe enough to deter people from engaging in dangerous or reckless behavior that could result in the death of another person. For example, a person who is sentenced to probation or a short prison term for involuntary manslaughter may not view the punishment as a strong enough deterrent to prevent them from engaging in similar behavior in the future.


Some people believe that involuntary manslaughter allows individuals to avoid being held fully accountable for their actions that result in the death of another person. This can be particularly problematic in cases where the defendant’s actions were highly negligent or reckless. For example, if a person is driving while intoxicated and causes a fatal car accident, they may be charged with involuntary manslaughter rather than a more serious offense like vehicular homicide. Some people may view this as inadequate punishment and feel that the person should be held more accountable for their actions.


Another argument is that the punishments for involuntary manslaughter are disproportionate to the severity of the offense, particularly when compared to punishments for more serious offenses like murder. For example, a person who is sentenced to probation or a short prison term for involuntary manslaughter may receive a much lighter punishment than a person who is convicted of murder and sentenced to life in prison. This can be seen as unfair to some people.


Some people argue that the concept of involuntary manslaughter is limited in its applicability, and that it does not adequately address cases where the defendant’s actions were intentional but did not meet the threshold for murder. For example, if a person intentionally causes an accident that results in someone’s death, but did not have the intent to kill that person, they may be charged with involuntary manslaughter rather than murder. Some people believe that this is an inadequate way to address such cases and that there should be a separate charge for intentional actions that result in death but do not meet the criteria for murder.

Let’s now move on and discuss UDAM specifically.

UDAM (Unlawful Dangerous Act Manslaughter)

Unlawful Dangerous Act Manslaughter, also known as UDA Manslaughter, is a type of criminal offense that involves the accidental killing of another person. It is a lesser offense than murder, which involves the intentional killing of another person. The key difference between UDAM and murder is the lack of intent, or Mens Rea (MR), to kill.

UDAM is also known as constructive manslaughter because the crime is constructed by looking back at the events that led to the victim’s death. In other words, the Actus Reus, or physical act, of the crime is homicide, but the Mens Rea, or mental intent, is derived from a base crime that is then built up, or constructed, into the Mens Rea for homicide.

In other words, a crime has been committed, and this leads to the death of a human being. However, determining the exact sequence of events and the mental state of the accused at the time of the offence can sometimes be clear and sometimes very opaque.

UDAM is a lesser offence than murder, but it is still a serious crime that can result in significant penalties. It involves the accidental killing of another person and is constructed by looking back at the events that led to the victim’s death. Determining the exact sequence of events and the mental state of the accused at the time of the offence can be challenging, but it is essential in determining the appropriate charge and punishment.

Let’s take a look at two examples, one that is extremely serious and one that is less serious.

Imagine that John and his accomplice, Jane, decide to rob a local convenience store. They enter the store with their faces covered and armed with a gun. John points the gun at the clerk and demands money while Jane empties the cash register.

As they leave the store, a customer enters and sees what is happening. The customer tries to tackle John and grab the gun, but John panics and accidentally pulls the trigger. The bullet hits the customer, who falls to the ground and dies.

In this case, John and Jane are both guilty of robbery, a serious crime involving violence or the threat of violence. However, John’s actions have also resulted in the accidental killing of the customer, which means that he could be charged with involuntary manslaughter.

Even though John did not intend to kill the customer, his reckless behaviour with the gun (such as pointing it at the clerk and pulling the trigger during a struggle) led to the customer’s death. This satisfies the elements of involuntary manslaughter, which require the accidental killing of another person as a result of reckless or negligent behaviour.

Jane, on the other hand, may not be charged with involuntary manslaughter because she did not handle the gun and did not directly cause the customer’s death. However, she could still be charged as an accomplice to involuntary manslaughter.

I personally feel that it is fair in this example that John should be held responsible for the death of the bank customer, and should end up with a similar sentence as he would receive if he was convicted of murder. However, involuntary manslaughter does not carry the possibility of a life sentence, with 18 years of prison time being the maximum possible.

On the flip side, we can imagine an example such as the following:

One evening, two college students, Jack and Mike, were hanging out in their dorm room. They were having a casual conversation, but things started to get heated when they disagreed on a topic they were discussing. Mike insulted Jack, who was feeling frustrated and annoyed and pushed Mike. However, Mike lost his balance and fell to the ground, hitting his head on a nearby table. Mike was rushed to the hospital, but unfortunately, he did not survive the injury. Jack was devastated by what had happened and couldn’t believe that his actions had led to Mike’s death. It could be argued that a homicide verdict for a relatively unlikely outcome does not reasonably describe the defendant’s level of blameworthiness.

It would be unlikely that this would be in the public interest to prosecute this crime and Jack is obviously not a menace or threat to society at large. This was just an unfortunate accident and it is likely that Jack will be psychologically affected for the rest of his life as well.

So what is clear at this stage is that there is a need to have a methodology to understand what UDAM is and what is not.

This is rather straightforward, but there are quite a few different components. We need to ensure that the following is true:

  1. There was an act.
  2. The act was unlawful.
  3. The act was dangerous
  4. The act led to the death of a human being.
  5. There was Mens Rea for the Act

Let’s go into all of these in detail, and then we can work out an equation to showcase criminal liability for UDAM.

There was an act.

This may sound obvious and redundant, but it’s not. You can attract, in some cases, criminal liability by an omission instead of an act. However, that is not the case for UDAM — there has to be a physical act.

It is worth remembering that, as a general rule, members of the public do not owe each other a duty to act. You can walk past a small child drowning in a pond and decide that you want to continue walking, and in almost all cases, he will not track criminal liability. Obviously, if it is your child, then you would attract criminal liability. We will discuss this issue of a mission at length during a discussion of Gross Negligence Manslaughter.

The Act must be unlawful.

This is called the base offence, out of which we construct the homicide offence. It has to be a crime, and it cannot be a civil wrong, as shown in R v Franklin [1883].

If there was no unlawful act, we could consider GNM instead of UDAM. Statutory offences also do not count as unlawful acts, and this is purely to keep all of those separate into GNM.

Several critical cases are worth reviewing here.

The first is R v Lamb [1967], in which a rather unusual incident occurred. The defendant jokingly pointed a revolver at a friend and pulled the trigger. Both of them thought the barrel was empty. Unbeknownst to them, the cylinder would rotate when the trigger was pulled and place a bullet in the chamber, which then fired. Tragically, the friend was killed.

The Court of Appeal determined that the crime of unlawful act manslaughter had not been established. This was because the prosecution could not prove an unlawful base act (i.e. assault) had occurred that could then be constructed into a more serious charge.

Furthermore, D and his friend did not possess the Mens Rea for the base offence of assault, as they assumed it was just a joke and would not cause any harm.

This case made it evident that the prosecution must demonstrate the Actus Reus and Mens Rea of the base offense to satisfy the unlawful act criterion.

The prosecution was unsuccessful in proving any element of intent, which meant they failed to prove both assault and involuntary manslaughter.


There are other cases where the defendant had defences for the base offence, so a case of involuntary manslaughter could not be made.

In R v Scarlett [1993], a criminal case that was heard in the Court of Appeal in 1993, the defendant, D, was charged with the manslaughter of the victim, V.

D threw V out of a pub, and the violence was in self-defense. It appears that V fell down some stairs and died as a result of this incident.

The Court of Appeal considered whether D was guilty of manslaughter in this case. In order to establish manslaughter, the prosecution must prove that the defendant committed an unlawful act that caused the victim’s death. In this case, the court found that D’s actions were not unlawful because they were done in self-defense. As a result, D was acquitted of the charge of manslaughter.

This case is an example of the principles of self-defense and the defence of others being applied in the criminal law of the United Kingdom. It demonstrates that an individual is justified in using force to defend themselves or others if they reasonably believe they are in imminent danger of harm. It also illustrates that an individual will not be found guilty of a crime if they were acting in self-defense and their actions were not unlawful.

A strange case is R v Slingsby [1995], where the defendant was digitally penetrating the victim. This actually confused me when I initially read this case, as I couldn’t understand how you could “digitally” penetrate someone, then I realized that it meant using digit — fingers.

The defendant was wearing a signet ring, which caused an internal injury to the victim. This injury eventually developed into septicemia, a severe infection that then lead to organ failure and death.

Because there was no unlawful act to create a base offence, the conviction of D was overturned on appeal.

The Act must be dangerous.

This should always be followed by “according to the Church Test.”

LawTeacher gives a good overview of the case.

Facts: Mr Church and the victim were in a van for sexual purposes. The victim started mocking him and a fight ensued. He knocked the victim semi-conscious. After his attempts to rouse her proved unsuccessful, he panicked, thought the victim was dead and threw her into the river. The victim’s gravely injured body was found in the River Ouse; the cause of death was drowning. Mr Church was convicted of manslaughter. He appealed his conviction.

Issue: Mr Church argued that the basis of his guilty verdict could not be criminal negligence, as the trial judge had only directed the jury on recklessness, nor provocation, as it was not adequate based on the facts. Thus, the only possible basis for manslaughter was that an unlawful act caused the death. He claimed, however, that the jury was misdirected on the relevance of his mistaken belief in the victim’s death when he threw her into the river, as Mens Rea is an essential element of manslaughter.


Decision/Outcome: The nature of directions given on criminal negligence have to be decided based on the circumstances of each case – in the present case, it was sufficient to direct the jury about utter recklessness. Secondly, the commission of an unlawful act does not in itself make a manslaughter conviction inevitable. It is only satisfied if the unlawful act is such that all reasonable people would realise that the act would subject the victim to the risk of at least some harm resulting from it. The trial judge had thus misdirected the jury by claiming that Mr Church’s belief in the victim’s death when he threw her into the river was irrelevant. However, despite the misdirection, there was no substantial miscarriage of justice on the whole because, on proper direction, the verdict would necessarily have been that of guilty.

So the test must be objective: Would a reasonable person have foreseen risk of some harm. It does not matter if D did not foresee the risk themselves.

That last part is confirmed in the case of R v Goodfellow [1986].

In this case, the defendant developed a plan to obtain a new council house by convincing authorities that he and his family were in danger from unknown individuals and needed a new, safer home. To further this plan, Goodfellow set fire to his own house while his family was inside, believing that he could safely evacuate them. He intended to blame the fire on the individuals he claimed were threatening him and his family.

Unfortunately, Goodfellow was incorrect in his belief that he could evacuate his family safely, and three people, including his family members, died in the fire. Goodfellow was ultimately charged with and convicted of involuntary manslaughter, a crime involving causing another person’s death through criminal negligence or recklessness.

In this case, Goodfellow’s actions in setting fire to his own home with his family inside demonstrated a reckless disregard for their safety. His belief that he could evacuate them safely did not mitigate his responsibility for their deaths. The conviction for involuntary manslaughter reflects the fact that Goodfellow’s actions were not intentional but were nevertheless dangerous and led to the loss of life

The act led to the death of a human being.

Just to stress the core point again: there must have been no intention to cause death. Otherwise we are dealing with murder or voluntary manslaughter.

For this point, we need to follow the typical factual and legal causation process. This requires the “But for” test, an unbroken chain of caution, and for the cause not to be remote, and also to consider the Thin Skull Rule.

We go through all of these steps to determine if the defendant’s actions were a foreseeable cause of the harm and that it was reasonable to hold the defendant legally responsible for the harm based on the circumstances.

However, this can get quite complex when we consider cases that involve drug dealers and victims who commit suicide.

In cases involving the administration of illegal drugs, the issue of legal causation is often central to determining the defendant’s liability. If the defendant physically administers the drugs to the victim, there is a clear chain of causation linking the defendant’s actions to the harm suffered by the victim. In this situation, the defendant may be found culpable for the harm caused by the drugs, even if the victim voluntarily consumed the drugs.

On the other hand, if the defendant simply provides the drugs to the victim, and the victim voluntarily consumes the drugs on their own, the chain of causation may be broken. This is because the victim’s decision to consume the drugs is considered an intervening act that breaks the link between the defendant’s actions and the harm suffered by the victim. In this situation, the defendant may not be held legally responsible for the harm caused by the drugs.

However, this scenario has a potential loophole to still convict a drug dealer.

Suppose the victim takes the drugs supplied by the defendant and subsequently suffers an overdose, and the defendant fails to provide assistance or call for help. In that case, this could be considered gross negligence on the part of the defendant. In such a case, the defendant’s failure to act could be seen as a foreseeable cause of the harm suffered by the victim, and the defendant may be held liable for gross negligence manslaughter. The defendant’s failure to act in the face of a foreseeable risk of harm to the victim demonstrates a reckless disregard for their safety.

This ends Part 1; I’ll continue part two by completing the methodology for UDAM, then discussing some common criticisms of UDAM, and then moving on to GNM.


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