The defence of abandonment is available to accused liable as parties of an offence under s. 21(1) or 21(2), were two or more persons form a common intention to carry out an offence, such that they are not responsible for the offences committed by the other parties.
The purpose of this defence is to ensure that only those morally culpable are convicted and to encourage persons to withdraw from criminal activities and report them.
The basic common law test requires:
- there must be a change of intention and physical change of place;
- where practicable and reasonable, timely communication of the intention to abandon the common purpose to those who desire to continue in it.
- communication, verbal or otherwise, must be unequivocal notice upon the other party such that if the other proceeds he does so without the further aid and assistance of those who withdraw.
- that the accused took, in a manner proportional to his or her participation in the commission of the planned offence, reasonable steps in the circumstances either to neutralize or otherwise cancel out the effects of his or her participation or to prevent the commission of the offence.
What amounts to abandonment will depend on the circumstances of each case.
Abandonment must occur before the offence takes place.
A failure to provide clear and timely communication will likely defeat the defence.
The manner of communicating the abandonment will depend on how deeply involved the accused was in the joint enterprise. The more peripheral the involvement the less express the language of behaviour needs to be.
It is often necessary that that the accused testify to explain his intentions.
Whether a person withdraws or abandons the offence is a question of fact.
There is suggestion that abandonment may be available to those who are aiders or abetters.
Where group have jointly planned to commit a rape and murder and the accused assisted in the initial part of the illegal plan but then leaves part way through does not abandon the offence and can still be convicted of murder.
A party who abandons a planned robbery but was the one who provided the others with guns can be liable for the murder arising from the robbery.
R v Gauthier, 2013 SCC 32 (CanLII) at para 50
R v K.K.P., 2006 ABCA 299 (CanLII) at para 12
Gauthier at para 38
R v S.R.B., 2009 ABCA 45 (CanLII), at para 10 reversed on appeal
- R v S.R.B., at para 24 per dissent, dissent aff'd on appeal R v Bird, 2009 SCC 60 (CanLII),  3 SCR 638 ("change of intention on the part of the accused and, where practical and reasonable, a timely communication of the accused’s intention to abandon the common unlawful purpose")
- Gauthier added this last element, see para 50
- KKP at para 12
KKP at para 12
e.g. R v KKP at para 14
R v Miller, 1976 CanLII 12 (SCC),  2 SCR 680 at 708
R v Fournier, 2002 NBCA 71 (CanLII), (2002), 173 CCC (3d) 566 at para 22
- R v S.R.B., at para 19
KKP at para 14
- R v KKP at para 11
R v Ball, 2011 BCCA 11 (CanLII) at para 46
- R v S.R.B., 2009 ABCA 45 (CanLII) overturned on appeal R v Bird, 2009 SCC 60 (CanLII),  3 SCR 638
R v Joyce (1978), 42 CCC (2d) 141 (BCCA) (*no CanLII links)