Principals: section 21(1)(a) 

 

In cases in which an accused’s participation in an offence is alleged to be as a principal, the acquittal of one principal determines nothing in respect of the other: R v Smith, 2016 ONCA 25 at para 48

 

The exception arises where one of the principals is clearly innocent, but the trier of fact cannot determine which of them it is: Smith at paras 56-58

Party as Aider or Abettor: section 21(1)(b) and (c)

Before someone can be convicted for an offence as a party, the underlying offence must have been committed: R v Nguyen, 2016 ONCA 182 at para 48

If the offence is not committed, the proper offence may be "counselling an offence not committed" under s.464 of the Code: Nguyen at para 49

Where a trier of fact is satisfied that multiple accused acted in concert, there is no requirement that the trier of fact decide which accused actually struck the fatal blow: R v. Brouillard, 2016 ONCA 342 at paras 14-17

Party Liability to a Conspiracy

Aiding a conspiracy to achieve its unlawful object does not make someone a party to the conspiracy. Party liability to conspiracy is established only if someone encouraged or assisted the initial formation of the agreement, or encouraged or assisted new members to join a pre-existing agreement: R v Nguyen, 2016 ONCA 182 at paras 19-20