R. v. McRae, 2013 SCC 68 clarifies the elements of uttering threats. It is now clear the threats need not be communicated to the person threatened.
The actus reus of the offence of uttering threats will be made out if a reasonable person fully aware of the circumstances in which the words were uttered or conveyed would have perceived them to be a threat of death or bodily harm. The Crown need not prove that the intended recipient of the threat was made aware of it, or if aware of it, that he or she was intimidated by it or took it seriously. Nor must the words be directed toward a specific person; a threat against an ascertained group of people is sufficient.
The mens rea of the offence is made out if the accused intended the words uttered or conveyed to intimidate or to be taken seriously. It is not necessary to prove an intent that the words be conveyed to the subject of the threat or that the accused intended to carry out the threat. A subjective standard of fault applies. However, in order to determine what was in the accused's mind, a court will often have to draw reasonable inferences from the words and the circumstances, including how the words were perceived by those hearing them.