For Causation to be proved the prosecution must show that:
1. The defendants conduct was the factual cause of the consequence
2. The defendants conduct was in law the cause of the consequence
3. There was no intervening act which broke the chain of causation
This is where the defendant can only be guilty if the consequence would not have happened 'but for' the defendants conduct.
- The defendant used his pregnant girlfriend as a shield whilst he shot at an armed policeman. The defendants girlfriend was killed.
- She would not have died 'but for' the defendant using her as a shield. Convicted of her manslaughter.
There may be one person whose act may have contributed to the end consequence. The defendant can be guilty even though his conduct was not the only cause of the consequence.
The defendants conduct must be more than a minimal cause but does not have to be a sustantial cause.
Thin Skull Rule
This means the defendant must take his victim as he finds him. If the victim has something unusual about him which makes an injury more serious then the defendant will be liable for the more serious injury.
- A woman was stabbed and needed a blood transfusion to save her life however she was a Jehovah's witness and her religion forbade blood transfusions.
- She died and the the defendant was convicted of her murder.
The Chain of Causation
There must be a direct link from the defendants conduct to the end consequence. In some situations something else happens after the original act of the defendant which may break the chain of causation. This is known as an intervening act.
The chain of causation can be broken by:
1. An act of a third party
2. The victims own act
Medical treatment is unlikely to break the chain of causation.
- A soldier was stabbed in the lung, the staff at the hospital gave him artificial respiration which made the injury worse and the man died.
- The original attacker was still guilty of his murder as the stab wound was the overwhelming cause of the death
- The victim was given a tracheotomy to help him breath and died from rare complications of the tracheotomy.
- By the time he died the original wounds were no longer life threatening however the defendant was still liable for his death.
Act of a third party
- The victim was given an antibiotic but suffered an allergic reaction to it. One doctor stopped the use of the drug but the next day another doctor ordered a large dose of it to be given. The victim died from an allergic reaction to the drug.
- The actions of the doctor were held to be an intervening act which caused the death and therefore the defendant was not guilty of the murder.
Victims own act
If the defendant causes the victim to react in a foreseeable way then any injury to the victim will have been caused by the defendant.
- A girl jumped from a moving car in order to escape from sexual advances. The girl was injured through jumping from the car and the defendant was liable for her injuries.
If the victims reaction is unreasonable then this may break the chain of causation.
- A hitch hiker jumped from the defendants lorry and suffered head injuries. The defendant had made an attempt to steal the victims wallet. The courts held that this was an unreasonable reaction.
Was the victims conduct "within the ambit of reasonableness"
When the victim breaks the chain of causation it is known as the Novus Actus Interveniens.