What is Causation in Criminal Law?
In criminal law, causation essentially describes a cause and effect relationship between the defendants actions and the harm suffered by the alleged victim.
In order to establish a defendants guilt, the prosecution must prove beyond reasonable doubt that his or her actions were a substantial and significant cause of the harm. This means that although other factors may have contributed to the harm suffered, the defendant can in certain circumstances still be found criminally responsible. Homicide cases are often useful to illustrate the law relating to causation.
In the important case of Royall v R [1991] HCA 27, Kelly Louise Healey died after falling from the window of a sixth floor apartment. It was alleged that prior to her death, she had been engaged in a violent argument with her boyfriend, Mr Royall.
At trial, the prosecution put forward three possible explanations for her death:
1. That Mr Royall had pushed her out of the window,
2. That she had fallen whilst attempting to avoid an attack by Mr Royall, and
3. That she died whilst trying to escape life-threatening violence.
It was held that even though Ms Healey may have directly brought about her own death by jumping out the window, Mr Royall was ultimately responsible for her death as
he created a well founded apprehension that she would be subjected to further violence if she remained in the apartment.
Accordingly, the court found that Royalls actions were the substantial or significant cause of Ms Healeys death.
In criminal cases, the question of whether the defendants conduct substantially or significantly brought about the deceaseds death is left to the jury. Where there are several different possibilities for the death, as was the case in Royall, the jury is not required to determine the exact cause of death but rather, they should simply focus on whether the defendants actions substantially contributed towards the death.
http://nswcourts.com.au/articles/what-is-causation-in-criminal-law/
There are other cases on this link too.