Actus Reus (Part 1).

Actus Reus (AR) is Latin for “Guilty Act”. This comes from the principle stated by Edward Coke, “actus non facit reum nisi mens sit rea” which means “an act does not make a person guilty unless (their) mind is also guilty”.

The easiest way to conceptualize Actus Reus is to think of it as the physical act of committing a crime.

This juxtaposes to Mens Rea (MR), Latin for “Guilty Mind”. I covered Mens Rea at a basic level in my essay on the equation to define criminal liability, so we won’t take time to review this again.

It is important to note that AR is an absolute requirement for a criminal act, unlike MR, which sometimes is not required to be guilty of a criminal act. An example of this would be drunk driving, without knowing that you were over the legal blood alcohol limit.

That said, you don’t have to take the specific end criminal action to commit AR; planning can also be a crime. For instance, a potential terrorist may want to blow up a building and murder numerous innocent civilians. If they are only thinking about it, without taking any positive action towards bringing this about, they are not guilty of any crime. But, if they start to take planning actions, such as reviewing building schematics, reviewing the best areas to place explosive charges, and observing the schedules of the security team at the building, they have taken action (AR) and would be guilty of a crime.

Without AR, a Defendant (D) cannot be guilty of a crime. In other words, you cannot commit a crime purely by thinking about something, you have to do something and move atoms in the physical world.

Typically, AR and MR come together to define the specific crime. For instance, let’s imagine you have committed homicide: the unlawful killing of a human being.

Is this murder? Well, now it depends on the MR. If the killing was accompanied by an intention (the MR) to kill or cause Grievous Bodily Harm (GBH), the killing becomes murder.

In most serious crimes, a defendant can only be guilty of a crime if their behaviour was criminal (AR), with a blameworthy state of mind (MR).

Interestingly, AR concerns itself only with the what, not the how. It does not matter how the victim (V) is shot, stabbed, strangled, starved, electrocuted, or tortured to death.

Homicide is not defined by any single act. So, the prosecution does not necessarily have to show that D killed with a particular action like shooting or stabbing! This is counterintuitive, but one can easily imagine cases where detectives cannot find the body or know the cause of death but have enough evidence that D is guilty.

AR can actually define two things:

  1. The behavior of D — Some crimes do not have a direct victim, such as speeding in a car on a completely empty road. This would be because of the potential danger to society if everyone behaved the same way.
  2. The results of D’s actions — Other crimes are only crimes if there is a result and a victim, thus you have to kill someone to commit a murder.

This entire concept of AR and MR has come under a fair amount of criticism for being overly complex and for trying to use umbrella terms for wildly different.

No doubt the actus reus–mens rea distinction is a logical and natural extension of the obvious empirical difference between a person’s conduct, which we can directly observe, and his intention, which we cannot. … [W]hat we refer to as actus reus requirements or as mens rea requirements are in fact a collection of entirely distinct doctrines. Four doctrines typically described as the actus reus requirements include what I shall refer to as the act requirement, the rules governing omission liability, the voluntariness requirement, and the objective elements of offence definitions. … Four doctrines typically described as the mens rea requirement include what I shall refer to as present-conduct intention, present-circumstance culpability, future-result culpability and future-conduct intention. Whilst these doctrines are grouped together as actus reus or as mens rea, the doctrines within each group have no common characteristic and no common function. Grouping the doctrines as actus reus or as mens rea is problematic because it obscures the fact that there are different doctrines at work and it misleadingly suggests that the doctrines share a common characteristic or function.

P. Roberts, ‘The Actus Reus–Mens Rea Distinction’ in S. Shute, J. Gardner, and J. Horder (eds), Action and Value in Criminal Law (Clarendon Press, 1996)

Despite the criticisms, the AR and MR distinction has survived the test of time. I’ve read somewhere that the older an idea, the more time has had to be reviewed and battled, and if it standing around, it is either very good or there is a significant amount of dogma attached to it! I am not sure what’s the case with the AR and MR distinction.

So, let’s dig further into AR, and explore all the consequences, exceptions, and ideas related to it. Before we dive into the different types of AR, it is worth highlighting what AR is not and what constitutes AR.

AR Must Be The Cause of the Harm!

This may seem self-evident, but for an act to be AR, it has to be the cause of the harm.

This is not as straightforward as it may first appear because there are two different types of crimes.

  1. Conduct crimes — These prohibit specific behaviour. The offence definition will require no harm.
  2. Result crimes — These require that conduct causes particular harm to an individual.

Result crimes are generally far more serious than conduct crimes. A few examples of a conduct crime are driving over the speeding limit on an empty country road and being drunk in public, even if there is nobody around.

We still punish conduct crimes because this type of behaviour is not scalable in society. If everyone behaved this way, we would all be worse off. So, the idea behind criminalizing this behaviour is to create a set of incentives that nudge society in the “right” direction — so this is essentially a matter of public policy. As a country, we decide that we don’t like public drunkenness, and thus we outlaw it.

The other reason is that conduct crimes can easily lead to result crimes if the circumstances line up. While you may not cause any harm to anyone by driving drunk in a country lane, you only know that for certainty after the fact. There could be someone walking down that street or another car, and your impaired reaction times could cause a fatal accident. It is just luck of the draw that it didn’t happen this time.

It is quite clear why we criminalize resulting crimes, but it is worth reviewing. The purpose of punishing criminals is fivefold:

1. Deterrence

The idea behind deterrence is that it prevents future crimes from happening. It does this by frightening would-be criminals.

Deterrence can be split into two: specific deterrent and general deterrence.

Specific deterrence aims to ensure that the defendant in question learns from his punishment and does not commit any further crime in the future once he is integrated into society.

General deterrence aims to frighten the public at large, which will inevitably contain a percentage of criminals. I have watched copious amounts of maximum security prison documentaries, and being incarcerated in one of these places for decades is something that I honestly would not want to experience. Thus, I moderate my behaviour to reduce the risk of this happening — thus, I don’t commit any major crimes! I assume this train of thinking is why, in the past, executions such as beheadings and hangings were carried out in public.

2. Incapacitation

Incapacitation works by removing a defendant from society for the public’s safety.

This can be done in three escalating methods: house arrest, imprisonment in a dedicated facility, and finally, killing the defendant (i.e. the death penalty).

House arrest can work well for non-violent criminals and does not create too much cost for society as a whole. Full-time imprisonment is costly and should typically be reserved for violent crimes or defendants who are dangerous to society.

The death penalty is highly controversial, and many studies claim that it has no deterrent effect and that it is more expensive than life imprisonment due to the numerous appeals. Thus it is just a more expensive and brutal method of incapacitation.

Notably, some countries like Singapore have the death penalty for non-violent crimes such as drug smuggling. This is an approach which is extremely difficult to justify morally. It is much easier to understand a death sentence for a serial killer like Ted Bundy or Jeffrey Dahmer.

3. Rehabilitation.

Rehabilitation has the same aim as deterrence, preventing future crime, but uses a different method: behaviour change in the defendant.

Typical examples of rehabilitation can include treatment to overcome drug addiction, psychological counselling, vocation programs, and structured education courses.

Often, courts can combine incapacitation, or the threat of incapacitation, with rehabilitation. So, either mandatory programs within a prison, or a deal where non-violent offenders can be on parole as long as they participate in the rehabilitation programme. This is beneficial because it keeps spaces open in prisons for more violent offenders.

4. Retribution

Retribution, in the same ethos as deterrence and rehabilitation, prevents future crime. But not from the defendant! The idea behind retribution is that it provides victims, and society at large, the feeling that there has been justice. This means that non-state actors do not need to engage in vigilantism or additional criminal behaviour to “get even” or “serve justice”.

5. Restitution

Restitution is different from the above because it does try to right some of the wrongs that the criminal defendant has caused. This is by punishing the defendant financially and ordering them to pay the victim for the harm they have caused. The fine can be for numerous reasons, including damage to property, physical injuries, and covering some of the costs of the criminal prosecution process.

So, now that we have covered why we punish crimes, let’s go back to the two types of crimes. Let me reiterate here:

  1. Conduct crimes — These prohibit certain behaviour. The offence definition will require no harm.
  2. Result crimes — These require that conduct causes particular harm to an individual.

For the conduct crime, we do not have to deal with causation. The very act of doing something, means that you are breaking the law.

But, with the more severe type of crime, the results crime, we do need to prove that the AR actually caused the criminal result! If we don’t, we may prosecute a completely innocent person.

When discussing causation in criminal law, we need to consider both factual causations as well as legal causations.

Factual causation is whether or not the conduct of the defendant causes the result. Did the physical actions of the defendant have physical, real-world results, or a chain of results, that ended in harm?

Legal causation reviews whether the defendant should be held legally responsible for the consequences of his actions.

There are five tests to determine whether causation can be established. The first two deal with factual causation, and the final three deal with legal causation.

Before one ever looks for legal causation, factual causation must be determined.

Test 1: The “But-For” Test.

The “But-For” test is often called the sine qua non test.

This test, on initial review, appears to be deceptively simple. It just asks the question:

But for the existence of X, would Y have occurred?

Or, to put it more simply:

But for the actions of the defendant, would the result have occurred?

If the answer is No, then there is a substantial argument that the defendant’s actions caused harm to the victim.

If the answer is Yes, the defendant cannot be guilty of the particular crime because the harm would have happened anyway.

For instance, we can see in R v White (1910):

D put cyanide in his mother’s drink with the intention of killing her. She was later found dead next to the cup which was only three-quarters full. Medical evidence revealed that she had died from heart failure, not poisoning. Factual causation between D’s attempted poisoning and death could not be proved. D could not therefore be convicted of murdering his mother. He was only guilty of attempting to do so.

I bolded the last sentence because D was still charged with a crime, not the initial suspect crime of murder but of attempted murder.

There is another caveat, and that is when D’s actions are a contributing factor, but only minimally so. These can be disregarded. A typical example, according to Loveless, J., Allen, M. and Derry, C. (2022), is “a doctor who only accelerates death by minutes or hours through the administration to a terminally ill patient of a high dose of a pain-relieving drug for the purpose of palliative care does not cause death.”

As you’re probably starting to see, nothing in Criminal Law is quite as simple as it looks. There are significant criticisms concerning the “But-For” test, which are well founded and that both Civil and Criminal Law have had to deal with.

The first is that there can be tenuous relations between actions and that almost anything if we try hard enough, can be construed as a “But-For” cause. In the end, everything was the fault of the Big Bang that created the universe 😉

Whenever I am in the wrong in life, I prefer to blame my mother for being born. Yes — she does read these essays.

For a more practical example, a walkway is closed for repair work. A woman has to take an alternate, more dangerous way home at night and is sexually assaulted. Is the manager in charge of the community’s road repair scheduling criminally liable for her rape? After all, if he had not scheduled the road repairs, the rape would never have happened. While this is a genuine cause-and-effect example, it would be deemed too remote to justify any liability. But I am sure that many examples are less clear and more controversial.

The second major criticism is that we can assign over-causation and also merged causations. The typical example used here is if two Ds shoot a V at the same time. In theory, they would both be able to showcase that they passed the “But-For” test because if they did not take their individual actions, the results would have been the same.

Several solutions are used for the above, such as:

  • Substantial Factor Test — This test asks whether D’s actions were a substantial factor in causing the harm, even if they were not the only factor causing the harm. A common law school case study is when D creates one fire, and the weather causes another fire. V loses their house in one giant fire when the two fires merge. Even if D didn’t start a fire, V might have lost their house in the other fire. The test here is to understand how important a factor D’s actions were in the harm caused.
  • Likelihood of Survival Test — This test asks the question, “Did D’s actions reduce the survival changes of V”? Obviously, this is very specific to homicide. If D’s actions significantly reduced V’s survival chances, then D may be found guilty.
  • Acceleration Theory — If the defendant’s action caused a victim to die sooner than the victim would have otherwise died, the defendant is guilty.
  • Proximate Cause — This asks where D’s actions are closely related to the harm caused and if they are the primary, or predominant, cause of the harm.

So that’s an overview of the “But-For” test to check if there is factual causation between D’s actions and the harm experienced by V.

Test 2: The “De-Minimis” Principle.

This test is named after the principle “de minims non curat lex” established in common law. This Latin translates into ‘the law does not concern itself with trifles.’

This is where an offence may have technically been made, but it is so trivial in importance that it does not warrant criminalization. An example may be a one-off assault, a light poke of a finger in the arm, or the theft of mere cents.

Additionally, in criminal matters, the de minimis principle is based on the fact that it is unreasonable for D to be held accountable for every single consequence flowing from their original act. If their contribution to V’s harm is minor and completely unforeseeable, then this test is not passed, and D has not engaged in AR.

So, this is the end of the factual causation tests, and now we can move on to legal causation. In other words, while we are sure that D’s actions caused harm to V, we still need to show that D is legally responsible for the consequences of his actions.

Test 3: The Thin Skull Test.

The idea behind this test is that “you must take your victim as you find them”.

This means that the chain of causation will not break due to unforeseeable acts by V after D’s criminal act.

The case R v Blaue (1975) sheds some light on this:

D stabbed V, a woman, in a street attack, piercing her lung. At hospital, she refused a life-saving blood transfusion for it was contrary to her religious beliefs as a Jehovah’s Witness. Consequently, she died and D was convicted of manslaughter on the grounds of diminished responsibility, the court holding that the wounds were the cause of death. D appealed on the grounds that V’s decision to refuse the blood transfusion was unreasonable and should break the chain of causation. The court disagreed.

Lawton LF further elaborates:

In Reg. v. Holland, 2 Mood. & R. 351, the defendant in the course of a violent assault, had injured one of his victim’s fingers. A surgeon had advised amputation because of the danger to life through complications developing. The advice was rejected. A fortnight later the victim died of lockjaw. Maule J. said, at p. 352: ‘the real question is, whether in the end the wound inflicted by the prisoner was the cause of death.’ That distinguished judge left the jury to decide that question as did the judge in this case. They had to decide it as juries always do, by pooling their experience of life and using their common sense. They would not have been handicapped by a lack of training in dialectic or moral theology. Maule J.’s direction to the jury reflected the common law’s answer to the problem. He who inflicted an injury which resulted in death could not excuse himself by pleading that his victim could have avoided death by taking greater care of himself: see Hale’s Pleas of the Crown (1800 ed.), pp. 427–428. The common law in Sir Matthew Hale’s time probably was in line with contemporary concepts of ethics. A man who did a wrongful act was deemed morally responsible for the natural and probable consequences of that act. Mr. Comyn asked us to remember that since Sir Matthew Hale’s day the rigour of the law relating to homicide has been eased in favour of the accused. It has been – but this has come about through the development of the concept of intent, not by reason of a different view of causation…The physical cause of death in this case was the bleeding into the pleural cavity arising from the penetration of the lung. This had not been brought about by any decision made by the deceased girl but by the stab wound. Counsel for the appellant tried to overcome this line of reasoning by submitting that the jury should have been directed that if they thought the girl’s decision not to have a blood transfusion was an unreasonable one, then the chain of causation would have been broken. At once the question arises – reasonable by whose standards? Those of Jehovah’s Witnesses? Humanists? Roman Catholics? Protestants of Anglo-Saxon descent? The man on the Clapham omnibus? But he might well be an admirer of Eleazar who suffered death rather than eat the flesh of swine … It has long been the policy of the law that those who use violence on other people must take their victims as they find them. This in our judgment means the whole man, not just the physical man. It does not lie in the mouth of the assailant to say that his victim’s religious beliefs which inhibited him from accepting certain kinds of treatment were unreasonable. The question for decision is what caused her death. The answer is the stab wound. The fact that the victim refused to stop this end coming about did not break the causal connection between the act and death.

But it can get more complex than this.

For instance, what if V refuses treatment on purpose, knowing it will lead to death, out of spite? And that this is done specifically to damage D and ensure a lengthy prison sentence. Then it seems absurd to blame D for the cause of V’s death, unless we believe that V’s state of mind, and the spite and anger that was generated, was caused by D’s initial criminal actions.

Test 4: Operative and Significant Cause.

The Oxford Reference defines this as follows:

The defendant’s act must be an operative and substantial cause of the consequence.

A guilty verdict needs to be “beyond reasonable doubt”. For causation to be established, we only need the “balance of probabilities.” Thus, it requires at least a 51% chance that the defendant’s actions caused the damage.

In other words, was it more likely than not that D’s actions caused harm to V?

Test 5: – Novus Actus Interveniens

An event between D’s action and V’s harm can break the chain of causation.

The chain of causation needs to remain unbroken from the moment that D commit a potential criminal activity to the time when V experiences the harm that creates the resulting crime.

If the chain of causation between D and V is broken, this is regarded as an intervening event which is called a Novus Actus Interveniens.

This specific test asks if there are any Novus Actus Interveniens that make D not legally responsible for the outcome.

Normally, when there is a Novus Actus Interveniens, this comes from a third-person intervention, but it could also be a natural event like a fire.

The important thing is that the act by the third person is voluntary. If they are forced to take certain actions due to D’s behaviour, then this will not be seen as a voluntary intervention. An example here would be a police officer who is forced into a shootout with D, and then V is accidentally shot by the police officer while D is using V as a human shield.

This test is quite complex, and I won’t cover the entirety of all the considerations. Still, there are specific ones I will review another time with regard to the supply of illegal drugs, medical treatment, and separate interventions by the victim themselves.

AR can be situationally dependent.

Many crimes require a specific action to happen within a particular set of circumstances. Otherwise, the action is entirely legal.

Let’s take rape as an example. Section 1 of the Sexual Offenses Act 2003 states the following:

(1) A person (A) commits an offence if—

(a) He intentionally penetrates the vagina, anus or mouth of another person (B) with his penis,

(b) B does not consent to the penetration, and

(c) A does not reasonably believe that B consents.

(2) Whether a belief is reasonable is to be determined having regard to all the circumstances, including any steps A has taken to ascertain whether B consents.

(3) Sections 75 and 76 apply to an offence under this section.

(4) A person guilty of an offence under this section is liable, on conviction on indictment, to imprisonment for life.

So, we can summarize that rape, according to this Act, penile penetration of the victim that is “without consent”.

But, if there is consent, then this would be normal (and hopefully enjoyable!) sexual activity between to consenting adults.

So, the physical action that defines normal sexual behaviour and the AR of rape is the same. The additional knowledge of intent and the situational specifics make this action criminal — or not.

So, the act of penile penetration alone will not amount to the AR of rape unless the circumstances and, where relevant, the result can be proved.

We can review a few other examples here as well.

Let’s bring up Section 1 of the Criminal Damage Act 1971:

(1) A person who without lawful excuse destroys or damages any property belonging to another intending to destroy or damage any such property or being reckless as to whether any such property would be destroyed or damaged shall be guilty of an offence.(

2) A person who without lawful excuse destroys or damages any property, whether belonging to himself or another—

(a) intending to destroy or damage any property or being reckless as to whether any property would be destroyed or damaged; and

(b) intending by the destruction or damage to endanger the life of another or being reckless as to whether the life of another would be thereby endangered;

shall be guilty of an offence.

(3) An offence committed under this section by destroying or damaging property by fire shall be charged as arson.

So, the AR here is to “destroy or damage any property”. But, there is the situational context that is “without lawful excuse”.

We don’t have to strain our imaginations to think of lawful excuses to damage properties.

I’ll provide a personal example here. I once had to kick down a door in an English summer language camp student dorm. The student was not responding, and we suspected he was injured or required medical assistance. It turned out that the student in question was not even in the room. Still, there was no question of me being criminally liable for damaging property because there was an apparent lawful excuse to cause the damage.

AR Cannot Be Status.

The critical thing is that AR is not status. This means you cannot be guilty purely by being who you are.

The U.S. Supreme Court ruled in Robinson v. California, 360 U.S. 660 (1962) that a California law making it illegal to be a drug addict was unconstitutional because the mere status of being a drug addict was not an act and thus not criminal. Note that the act of possession of drugs would still be illegal in this case, but then the police would have to catch D with drugs on his person.

This is important and something worth upholding because if we were to start to define AR as status, we could easily find ourselves with governments with 20th-century totalitarian twists who can then use the law to criminalize and persecute people of certain races, beliefs, or lifestyles.

That’s it for Part 1. In Part 2, I will cover the different types of AR, including a significant discussion on when not taking action, can still be labelled as a “Guilty Act”.

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