How does the alternative-source rule reconcile reporter's immunity and defendant's fair trial rights?

The requirement of a threshold showing that no alternative source of information is available (hereinafter called the alternative-source rule) can, therefore, reconcile reporter's immunity and defendant's rights so as to give effect to both. Unlike the majority's multifactored approach, the alternative-source rule remains focused on the single decisive question: does the defendant need the information to obtain a fair trial? The alternative-source rule also incorporates a functional approach to the defendant's fair trial rights, based on the recognition that these rights exist within a framework of state law privileges and immunities. What one commentator stated of the communications privilege applies at least equally to the reporter's immunity: "A communications privilege would be of little value if a [criminal] defendant could override it whenever its invocation concealed evidence of some probative value. Courts must respect the legislative judgment that in some situations the social policy underlying a privilege should require that litigants be denied access to otherwise admissible evidence. The legislative establishment of a privilege should make the privilege-holder a disfavored source of information." (Defendant v. Witness, supra, 30 Stan.L.Rev. at p. 966, italics added.)