Actus+Reus

Voluntariness
Voluntariness must be proven in all criminal prosecutions. That is, the accused must have acted voluntarily, which must involve a willed muscular movement.

According to R v Butcher, actus reus consists of a whole series of voluntary acts, and not just the isolated event that causes the volitional act. In other words, the act of stabbing consists of holding the knife, raising it, and ultimately thrusting it.

There is a rebuttable presumption that the defendant's act or ommission was voluntary. If evidence is adduced that raises question of voluntariness then it falls upon the prosecution to provde beyond reasonable doubt that voluntary nature of the act.
 * Rebuttable Presumption**

Causation
In order to establish a causal connection, two elements must be proven beyond reasonable doubt:
 * 1) Factual Causation
 * 2) Legal Causation

Factual Causation adopts the 'but for' test, and requires but for that the defendant's act or ommission the victim died.

Legal Causation on the other hand looks at whether the defendant's act or ommission was the operating and substantial cause of the victim's death. This requires considering any possible extraordinary or intervening event that may have interrupted the causal connection. Examples of an intervening event include circumstances such as where medical treatment attributed to the death.

It goes without saying that the defendant's act or ommission must substantially or significantly contribute to the death of the victim. However, the substantial cause test employs an objective test that does not take into consideration what the defendant intended or foresaw as the likely consequences of their actions.
 * The Operating and Substantial Cause Test**

In R v Hallet the victim was left on the beach, and subsequently drowned as a result of the incoming tide. The court held that the natural force of the tide did not constitute an intervening event and that the defendants act of leaving the victim unconscious on the beach was still a substantial and operating cause of death.

Where the victim, as a result of a latent physiological or psychological condition, dies of an injury inflicted by the defendant, but from which a normal person would not have died, the pre-existing condition, will not be deemed to have broken the chain of causation.
 * The Egg Skull Rule**

For example, R v Blaue involved the stabbing of a Jehova's Witness who subsequently refused a blood transfusion and died. The court held that the refusal to accept the treatment did not sever the causal connection and the stab wound was the operating cause of death.

Medical treatment is capable of severing the chain of causation. In R v Jordan, the court held that the death of the victim could in part be attributed to the wrong treatment given to him while in hospital.
 * Medical Treatment**

However, in R v Smith the court found that there was no abnormal or palpably wrong treatment, but instead that the original wound was still an operating and substantial cause of death.

Lord Parker suggests that R v Jordan "should be regarded as a case decided on its on special facts and not as an authority relaxing the common law approach to causation".

In Victoria, R v Smith is considered good authority and was followed in R v Evans & Gardner. This case involved the death of a prison inmate from a bowel obstruction that developed following his treatment for a stab wound inflicted by the defendants. Here, the court found that the causal connection had not been broken by the medical treatment.

Sometimes death is caused by the act of fleeing or attempting to avoid being violently attacked. According to R v Royall the reaction of the victim severs the causal connection only if the reaction is unreasonable or disproportionate to the threat posed by the defendant. The requirements of the objective test enunciated by the majority are:
 * Flight and Self-Preservation**
 * 1) the defendant induced in the victim a well-founded apprehension of physical harm;
 * 2) that is was reasonable for the victim to wish to escape; nad
 * 3) that the victim selected a reasonable mode of escape, having regard to the accused's conduct and the feat it is likely to induce.