Factual causation is established using the “but for” test. This asks whether, “but for” the actions of the defendant, the consequence would have occurred (R v White).
LEGAL CAUSATION (STEP 1)
Legal causation involves a consideration of a series of factors which include the de minimis principle, whether there are any intervening acts and the thin skull rule.
Firstly the de minimis principle must be considered. The actions of the defendant do not need to be the sole cause or even the main cause of the consequence but must have made more than a minimal contribution (Kimsey).
LEGAL CAUSATION (STEP 2)
As part of legal causation, it must be shown that there were no intervening acts which could break the chain of causation and prevent the defendant from being liable.
There are 3 categories of intervening acts - acts of the victim, acts of 3rd person and an act of God (unforeseeable natural event).
ACT OF VICTIM
For the actions of the victim to break the chain of causation the victim must do something unforeseeable or unpredictable. In Roberts this was described as “daft and unexpected”.
ACTS OF 3RD PERSON
For the actions of a 3rd person to break the chain of causation they must overtake those of the defendant. It must be something independent of the defendant’s actions and serious enough to have caused the consequence (Cheshire).
ACTS OF GOD
An “act of God” could break the chain. A natural event or disaster that causes further harm. It must be so significant and unforeseen that it becomes the main cause of the consequence.
THIN SKULL RULE
The extent of harm suffered by the victim may be much more severe due to pre existing conditions. This includes both physical and psychological conditions. The Defendant must “take the victim as he finds them” and will be responsible for the full extent of harm. (R v Blaue).