Crown must prove the offence particularized

R. v. Sadeghi-Jebelli, 2013 ONCA 747:

[23]       When the Crown charges an accused with an offence, and particularizes the way the offence was committed, it must prove the offence as particularized in the charge.  The Supreme Court of Canada affirmed this principle in R. v. Saunders, [1990] 1 SCR 1020 at 1023.  McLachlin J. said:  "It is a fundamental principle of criminal law, that the offence, as particularized in the charge, must be proved".  So, for example, if the Crown charges an accused with trafficking in heroin, it cannot, without an amendment to the charge, obtain a conviction for trafficking in cocaine. 

[24]       This principle is grounded in fairness.  Particulars permit "the accused to be reasonably informed of the transaction alleged against him, thus giving him the possibility of a full defence and fair trial".  See R. v. Côté, [1978] 1 SCR 8 at 13.  This principle is subject to an exception for "mere surplusage", or information in the indictment that is not essential to the offence, but that exception does not apply here.  See R. v. Vézina, [1986] 1 SCR 2 at para. 49.