When it is shown that an informant was an eyewitness to an offense, that informant can in fact give testimony necessary to the fair determination of guilt or innocence. Anderson v. State, 817 S.W.2d 69, 72 (Tex.Crim.App. 1991). During the hearing on the motion to disclose, Appellant called Deputy Gutierrez to the stand who testified a Detective Guzman had informed him that a particular vehicle would be loaded with narcotics in the area, and it was based on this information that Deputy Gutierrez surveyed the area for the described vehicle in order to discover a traffic infraction that would enable him to pull it over. Appellant then called Detective Guzman, who testified that a confidential informant had provided his office with the information regarding the vehicle.

Rule 508(c)(2) requires disclosure when the testimony of the informant is "necessary to a fair determination of the issue of guilt, innocence," although the original three requirements are still factors that the court should consider. Anderson v. State, 817 S.W.2d 69, 72 (Tex.Crim.App. 1991). If it appears from the evidence or from other showing that the informer may be able to give such relevant testimony, an in camera hearing is required where the State has the opportunity to show that the testimony is not necessary to a fair determination of the issues of guilt and innocence.