ABSTRACT
A criminal offence that involves the activities of more than one defendant can present particular difficulties in terms of ascribing fault to those who play some part. At common law, three possibilities exist:
two or more defendants act together to commit a crime – as where D1 and D2 rob their victim, D1 punching the victim and D2 grabbing her bag. In this case both D1 and D2 are committing robbery – they would normally be regarded as co-principals. In such cases issues of accessorial liability should not arise (even though they may technically have been helping each other to commit the crime) as they can each be shown to have committed the completed offence as principals in their own right.
D1 carries out the robbery using a gun supplied by D2. In this case D1 is clearly the principal offender. D2 is not even at the scene of the crime. D2 may incur liability, however, on the basis of the part he played in providing the weapon. The type of liability D2 incurs here is sometimes referred to as secondary liability.
D1 robs the victim whilst D2 acts as a lookout. Here D2 is at the scene of the crime and the law tends to view such cases as a particular type of secondary liability sometimes called joint venture. Typically D2 will be regarded as having aided and abetted the robbery. In many cases it will not matter whether D2 is a secondary party or is involved in a joint venture, but as will be seen below, the courts have developed some complex rules governing the liability of those engaged in joint ventures where the principal offender has gone beyond the agreed or understood scope of the joint venture.
