Is a defendant required to articulate a defense in order to obtain the identity of an informer?

And in People v. Tolliver (1975) 53 Cal.App.3d 1036, 125 Cal.Rptr. 905, it was held that a defendant is not required to specifically articulate a theory of defense in order to secure a disclosure of the identity of an informer. The Tolliver court held that, if from the prosecution's evidence alone, there appeared a reasonable Possibility of favorable testimony by an undisclosed informer, the defendant was entitled to disclosure even though he has not articulated a specific theory of defense. The failure of the prosecution to provide disclosure of an informer's identity in these situations creates the result that a defendant is entitled to have the action dismissed against him on the ground that he has been denied his due process right to a fair trial.