Introduction
Causation in criminal law refers to the legal principle that establishes a direct link between the defendant's conduct and the resulting harm. It is an indispensable component of criminal liability, ensuring that an individual's actions are sufficiently connected to the prohibited outcome to warrant legal responsibility. Causation is divided into two distinct but interrelated concepts: factual causation and legal causation. Factual causation determines whether the harm would have occurred "but for" the defendant's conduct, while legal causation assesses whether the defendant's actions are sufficiently connected to the harm in a legal sense. Understanding these principles is essential for analyzing criminal cases where the chain of events between conduct and consequence may be complex.
Factual Causation: The "But For" Test
Factual causation establishes whether the harm would have occurred "but for" the defendant's actions. It asks the question: would the consequence have happened anyway if the defendant had not acted? If the answer is no, factual causation is established.
Example
Suppose an individual fails to maintain safety equipment at a construction site. As a result, a platform collapses, injuring workers. The question is: but for the person's omission, would the accident have occurred? If the accident would not have happened without the omission, then factual causation is present.
Limitations of the "But For" Test
The "but for" test can be problematic in cases involving multiple causes. When several factors contribute to the harm, it's possible for each to pass the "but for" test, leading to complexity in establishing causation. So, what happens when multiple defendants are involved, and each action alone would have caused the harm?
Consider two factories independently releasing pollutants into a river, resulting in the death of aquatic life. Each factory's discharge alone is sufficient to cause the harm. Applying the "but for" test to each factory suggests that neither is the factual cause, because the harm would have occurred due to the other's actions. This scenario demonstrates the limitations of the "but for" test in cases with concurrent causes.
Legal Causation: The "Substantial and Operating Cause" Test
Legal causation goes beyond factual causation to determine whether the defendant's actions are a significant contribution to the harm in a legal sense. Even if factual causation is established, legal causation must also be satisfied.
Legal causation can be seen as determining whether the defendant's actions set in motion a chain of events that leads to the harm, much like pushing the first in a line of dominoes. If an unforeseen hand interrupts and knocks over a domino further down the line, can we still say the initial push caused the final fall? In legal terms, if an intervening act is sufficiently independent and unforeseeable, it may break the chain of causation, absolving the original actor of legal responsibility.
Foreseeability and Remoteness
An important aspect of legal causation is whether the harm was a foreseeable consequence of the defendant's actions. If the outcome is too remote or unexpected, the causal link may be broken.
For example, if a person sets off a small firework in a public park, and unexpectedly, it triggers an underground gas explosion causing widespread damage, the defendant may argue that the ultimate harm was unforeseeable and too remote to establish legal causation.
The Thin Skull Rule
The thin skull rule dictates that the defendant must "take their victim as they find them." This means that if the victim has a hidden vulnerability that leads to more severe consequences than an average person would suffer, the defendant is still fully liable for the harm caused.
Example
Picture lightly tapping someone on the shoulder. Seems harmless, doesn't it? But what if that person has a medical condition that causes severe injury from even minor contact? Under the thin skull rule, the person who initiated the contact is liable for the unforeseen injuries.
Case Law: R v. Blaue [1975]
In this case, the defendant stabbed a woman who required a blood transfusion to survive. Due to her religious beliefs, she refused the transfusion and died. The court held that the defendant was liable for her death because he had to take his victim as he found her, including her beliefs. Her refusal was not an intervening act breaking the chain of causation.
Intervening Acts and Novus Actus Interveniens
An intervening act, or novus actus interveniens, is an event that occurs after the defendant's action and contributes to the harm, potentially breaking the chain of causation.
Third-Party Acts
Actions by a third party can sometimes break the chain if they are sufficiently independent and unforeseeable.
Case Law: R v. Pagett [1983]
In this case, the defendant used his pregnant girlfriend as a human shield while he shot at police officers. The police returned fire, and the girlfriend was killed. The court held that the defendant's actions caused her death. The police officers' return fire was a foreseeable response and did not break the chain of causation.
Victim's Own Actions
If the victim's own actions are a natural and foreseeable consequence of the defendant's conduct, the chain of causation remains intact.
Case Law: R v. Roberts [1971]
A young woman leapt from a moving car to escape unwanted advances from the defendant, sustaining injuries. The court determined that her actions were a foreseeable reaction to the defendant's behavior, so the causal link was maintained.
Medical Treatment
Generally, negligent medical treatment does not break the chain of causation unless it is so independent and potent in causing the death that it renders the original injury insignificant.
Case Law: R v. Cheshire [1991]
Here, the victim was shot and required surgery. Complications from a tracheotomy led to the victim's death. Despite potential medical negligence, the court held that the defendant's act remained a significant cause of death.
Case Law: R v. Jordan [1956]
In this case, the victim had been stabbed but was recovering well when doctors administered medication to which he was allergic, resulting in his death. The medical treatment was considered "pa