Special Masters serve without compensation, but for purposes of immunities are considered public employees of the government entity causing the search warrant to be issued.

Special Masters must be active members of the State Bar in good standing for at least five years. To avoid potential conflicts of interest, attorneys who devote a substantial amount of their practice to criminal law are not eligible to serve as Special Masters.

When a search warrant is issued for documents under the control of the specified professionals, the court appoints a Special Master to accompany the peace officer serving the warrant.

Section 1524 of the Penal Code requires that Special Masters be used in conducting searches under search warrants for documentary evidence in the possession of or under the control of certain professionals. Special Masters have been required since 1979. The use of Special Masters is designed to balance the interests of professionals and their clients in protecting confidentiality and of prosecutors in securing evidence of suspected criminal activity.

Special Masters are volunteer attorneys who accompany peace officers in searches for documentary evidence in the possession of or under the control of attorneys, physicians, psychotherapists and clergy.