T and R had a plan to kill their mother. They intended to ply her with alcohol and drown her in the bathtub.
T had a friend, JF. JF became aware of this plan. Thereafter JF became actively involved in discussing the plan and offering to assist therein. In particular, JF offered to provide an alibi; JF also advised T that she should give her mother 5 Tylenol 3’s as this would knock her out.
T and R killed their mother. R was charged with conspiracy to commit that murder. He was convicted. He appealed. His appeal was dismissed: 2013 SCC 12.
The key issue on appeal related to whether JF – or anyone – could be a party to a conspiracy; this route to liability was left with the jury.
Moldaver J, for the Court, began by noting that conspiracy is a form of inchoate liability [para 21]. However, unlike the situation with “attempt to commit conspiracy”, “being a party to a conspiracy does not involve staking one form of inchoate liability upon another” [para 24]. Moreover, Moldaver J noted that nothing in section 21 “suggests that party liability does not apply to offences that punish inchoate behvaviour [para 23].
Moldaver J concluded that the offence of being a party to a conspiracy is one known to Canadian criminal law [para 25].
The scope of liability for a party to a conspiracy is restricted, however, to “conduct that aids or abets the formation of the agreement that comprises the essence of the crime of conspiracy [para 43]. In other words, it is “limited to cases where the accused encourages or assist in the initial formation of the agreement, or when he encourages or assists new members to join a pre-existing agreement” [para 63].
It followed, Moldaver J held, that JF was not liable as a party to the conspiracy and the trial judge erred in leaving that with the jury. Nonetheless, the conviction should stand. Moldaver J offered the following as the overwhelming basis upon which JF was properly convicted despite the error:
The evidence implicating the appellant as a member of the conspiracy was overwhelming. The Crown presented a powerful body of evidence from which the jury could find that the appellant, with knowledge of the conspiracy between R and T, provided advice and offered assistance to them, with their knowledge and consent, for the purpose of facilitating the killing of their mother. As he said in his MSN conversation with T, shortly before the murder occurred, “I’m involved this much, I’m willing to help you out with any of it [T]” (A.R., at p. 197). That, along with other evidence which implicated the appellant in providing the Tylenol 3 pills and attending a restaurant after the killing to provide R and T with an alibi, provided the jury with all the evidence it needed to find an agreement between the appellant and R and T that the murder should be carried out. Nothing more was needed to establish the appellant’s membership in the conspiracy. It is immaterial that the appellant, unlike R and T, took no part in the actual killing of A.K. Once the jury rejected his explanation that he was not being serious, as it must have, a finding of guilt on the basis of membership was inevitable [para 65].
JF is an interesting case. The conclusion by the Court that one cannot be a party to a conspiracy already formed, would appear to cast a narrow scope for the offence of being a party to a conspiracy. On the other hand, the conclusion by the Court that JF was obviously (so obvious that the error did not warrant a new trial) a member of the conspiracy in this case, would appear to broaden the scope of being a member of the conspiracy.
It is well settled law that a conspiracy requires, inter alia, an agreement or intention to agree: R v Root, 2008 ONCA 869; United States of America v Dynar,  2 SCR 462. On these facts, whatever “agreement” there was occurred after R and T had already agreed to commit the murder. JF merely “agreed” to help them in that endeavor. This “agreement” resulted in him being a member of the conspiracy.
On these facts, the distinction between a party after the agreement has commenced (not an offence known to law) or becoming a member through “party” acts is not easily discerned.
Perhaps all of this is moot anyway, as Moldver J points out, JF could have, and perhaps should have been charged with first-degree murder anyway:
I should point out that in the circumstances, the decision on the part of the Crown to charge the appellant with conspiracy to commit murder very much softened the blow that could otherwise have befallen him. The assistance he provided to R and T in facilitating the murder, which they eventually committed, could well have led to a charge of first degree murder against him [para 66].