Introduction to Causation in Criminal Law

Note on Introduction to Causation in Criminal Law by Legum

Introduction to Causation in Criminal Law:


In criminal prosecutions, the prosecution identifies and targets an entity or a set of entities as being responsible for a crime. To secure a conviction, the prosecution must demonstrate that the entity or entities (known as the accused), caused the harm, or committed the offence. Thus, there must be a connection between the accused and the offence.

The act of connecting the accused to the offence is essentially causation in criminal law and will be the subject of this note.

Rule on Causation:

Before an accused can be held accountable for an offence, it must be established that he caused or is responsible for the actus reus for that offence.

Explanation of Rule:

For a person to be found guilty of murder, for instance, it must be shown that his actions or omissions caused the death of another. Failure to show this causal link will lead to the acquittal of the accused. In the case of R v Yeboah (a murder case), the accused shouted “thief thief!” and led a mob to chase the victim. The next day, the guy was found fatally injured and he never regained consciousness; the accused was charged with murder. It was held that

even if it could be conceded that the man after whom the accused led the crowd in hot pursuit, was the same man who was subsequently found unconscious, there was still no evidence connecting the accused with his death. If a crowd of people chased after a man in the belief that he was a thief, and he was battered to death, but there was no evidence which person or persons inflicted the blows or that they were acting in concert, a charge of murder could not hold against any of them

Thus, the court held that the prosecution had failed to connect the accused to the harmful act that caused the victim’s death.

Types of Causation in Criminal Law:

Causation in criminal law is divided into factual causation and legal causation.

Factual Causation (or Cause-in-Fact) :

This is the starting point of analysing causation and refers to the relationship between a defendant’s actions and the resulting harm or injury in criminal law. In criminal cases, the prosecution must prove that the defendant's actions were the factual cause of the harm to secure a conviction.

Establishing Factual Causation:

To establish factual causation, the “but for” test is applied. Thus, the prosecution must prove that the prohibited event would not have happened “but for” the acts or omissions of the accused.

The case of R v White established the “but for” test. In that case, the accused had put some poison in his mother’s drink to kill her. His mother took a few sips of the drink, went to bed, and died in her sleep. Medical reports revealed that she died of a heart attack, not the poison. The court established that the accused would have been guilty if the victim’s death would not have occurred, “but for” the accused’s acts of poisoning her drink. The accused was acquitted of murder but was liable for attempted murder.

The Insufficiency of Factual Causation:

Whilst proving factual causation may suffice to establish causation, there are cases where the prosecution must prove legal causation because factual causation would not suffice to establish liability or otherwise. For instance, it would be absurd to say a bus driver who failed to pick up a murder victim caused the murder because “but for the bus driver failing to stop the bus to pick up the victim, he would not have been at the location where he was shot and murdered by the accused.”

This reasoning, though consistent with the logic of factual causation, is simply absurd and capable of being used to establish a causal link between almost anyone and a crime. Legal causation fixes some of the absurdities that may arise following an application of factual causation.

Legal Causation:

Essentially, legal causation means that the acts of the accused must be an operative and substantial cause of the prohibited event. It is also often expressed as a question of whether the prohibited event is a foreseeable consequence of the accused’s acts.

In re-examining the bus driver example (supra), the harm caused to the victim was not a foreseeable consequence of the bus driver’s failure to pick up the victim. Rather, it was a foreseeable consequence of being shot, hence the shooter caused the victim’s death. Also, the act of shooting the victim was the operative and substantial cause of the victim’s death, and not the failure of the bus driver to pick up the victim.

The case of R v Smith helps explain this element of causation. The accused was a soldier who stabbed a comrade during a fight. The victim, while being rushed to the hospital by other soldiers, was dropped twice. Also at the hospital, the doctors failed to notice that one of the victim’s lungs was pierced and consequently provided an inappropriate and harmful treatment. The victim died at the hospital and the accused contended that the victim would not have died if he had received the appropriate care, or but for the failure of the doctors to provide appropriate care.

The court per Lord Parker CJ dismissed this contention and stated that

If at the time of death the original wound is still an operating cause and a substantial cause, then the death can properly be said to be the result of the wound, albeit that some other cause of death is also operating. Only if it can be said that the original wounding is merely the setting in which another cause operates can it be said that the death did not result from the wound. Putting it another way, only if the second cause is so overwhelming as to make the original wound merely part of the history can it be said that the death does not flow from the wound.

Thus, and for legal causation, the accused’s act must be an operating and substantial cause of the victim’s harm.

It is essential to note that the idea of “an operating cause and a substantial cause” as used in R v Smith does not mean the accused’s acts were the sole cause of the harm. It means that the accused’s acts must not be trivial, because the law ignores insignificant details (de minimis non-curat lex).

In the case of R v Benge, the accused was the foreman of a group of workers repairing rails at a train station. He was given a timetable containing the arrival times of trains. On one occasion, he misread the timetable and ordered that some rails be removed shortly before a train was scheduled to arrive. As required, Benge sent a crew member with a flag to go down 1,000 yards of the track to signal any incoming train to stop due to the removal of the rails, but the crew member only went about 540 yards down the track. The 1,000 yards was considered necessary because trains could stop within 1,000 yards of applying the break. Consequently, a train accident occurred killing a lot of people. Benge was charged with manslaughter and he contended that the accident would not have happened but for the contributory negligence of the crewman inter alia. The court held that the acts of the accused need not be the only cause of a prohibited event for him to be deemed to have caused the event and that it was irrelevant that the accident would not have occurred if other people had acted differently.