Anyone interested in claims to privilege by the media, especially claims in resistance to the execution of search warrants, will need to read R v National Post
 SCC 16 (7 May 2010).
I mention it here only in passing, for it would otherwise require lengthy exposition. The point that will attract the attention of readers familiar with R v Grant and the questionable application of that decision in R v Harrison (see my blogs for 18.7.09, and 19.7.09) is the two-dimensional nature of the conceptual model used in National Post, in contrast to the three dimensional model suggested in Grant.
Grant concerned the admissibility of improperly obtained evidence, and there is an obvious analogy between that and the issue in National Post. The link is whether seizure of the contested evidence would be improper and the consequences if it was.
National Post adopts the Wigmore criteria for deciding whether a claim to privilege should be permitted:
" The "Wigmore criteria" consist of four elements which may be expressed for present purposes as follows. First, the communication must originate in a confidence that the identity of the informant will not be disclosed. Second, the confidence must be essential to the relationship in which the communication arises. Third, the relationship must be one which should be "sedulously fostered" in the public good ("Sedulous[ly]" being defined in the New Shorter Oxford English Dictionary on Historical Principles (6th ed. 2007), vol. 2, at p. 2755, as "diligent[ly] . . . deliberately and consciously."). Finally, if all of these requirements are met, the court must consider whether in the instant case the public interest served by protecting the identity of the informant from disclosure outweighs the public interest in getting at the truth. See Wigmore on Evidence (McNaughton Rev. 1961), vol. 8, at § 2285; Sopinka, Lederman and Bryant: The Law of Evidence in Canada (3rd ed. 2009), at paras. 14.19 et seq.; D. M. Paciocco and L. Stuesser, The Law of Evidence (3rd ed. 2002), at pp. 163-67. Further, as Lamer C.J. commented in Gruenke:
"This is not to say that the Wigmore criteria are now "carved in stone", but rather that these considerations provide a general framework within which policy considerations and the requirements of fact-finding can be weighed and balanced on the basis of their relative importance in the particular case before the court. [p. 290]""
The fourth step is the weighing exercise that here is two-dimensional: the two public interests are weighed against each other.
" The fourth Wigmore criterion does most of the work. Having established the value to the public of the relationship in question, the court must weigh against its protection any countervailing public interest such as the investigation of a particular crime (or national security, or public safety or some other public good)."
" The weighing up will include (but of course is not restricted to) the nature and seriousness of the offence under investigation, and the probative value of the evidence sought to be obtained, measured against the public interest in respecting the journalist's promise of confidentiality. ...".
Notable here, where we are thinking of an analogy with the balancing involved in deciding the admissibility of improperly obtained evidence, is the linking of seriousness of the offence and the probative value of the evidence. Those are matters that could properly be imagined as belonging on a y-axis. Against them is the public interest against admission, and in the context of improperly obtained evidence this would be measured on an x-axis. These two axes would indicate two boundaries of a field of balance points, and the field would be divided, in a way reflecting policy, into areas of admission and exclusion.
This is a conceptually clear model, and avoidance of any suggestion of three-armed balances is welcome. The Grant model presented the difficulty of regarding as a third arm of the balance the impact of the impropriety on the accused; instead of seeing this as a third arm, it would be better to combine it with the "seriousness of the impropriety" arm, or to separate it out as a prerequisite to getting to the balancing stage in a way akin to the role of the first three of the Wigmore factors.
Beware! Teachers may even now be preparing their "compare and contrast" exam questions.