What is the legal test for disclosing the identity of a confidential informant?

If the informant is a material witness in the case, the trial court must order disclosure. "An informant is a material witness if there appears, from the evidence presented, a reasonable possibility that he or she could give evidence on the issue of guilt that might exonerate the defendant. [Citation.]" (People v. Lawley (2002) 27 Cal.4th 102, 159-160.)

"It is, of course, the defendant who bears 'the burden . . . to make a sufficient showing that the unnamed informer does have information which would be material to the defendant's guilt. [Citations.] This burden is met only where the defendant demonstrates through 'some evidence' [citation] that there exists a " 'reasonable possibility that the anonymous informant whose identity is sought could give evidence on the issue of guilt which might result in defendant's exoneration.' " ' [Citation.]" (People v. Gordon (1990) 50 Cal.3d 1223, 1245-1246.)