Defendants' petition for writ of prohibition/mandate arising from the district attorney's proceedings for civil commitment against them as sexually violent predators (SVP) is granted as Code of Civil Procedure section 1985(b) requires that a subpoena duces tecum be served with an affidavit setting forth in full detail the materiality of the items sought by the subpoena, and thus, the trial court erred by ordering Coalinga State Hospital (CHS) to comply with the issued subpoenas and with unspecified future subpoenas containing similar subject matters. A writ of mandate is issued commanding the trial court to: 1) vacate its orders releasing records; 2) return any documents produced by CSH or the Department of Corrections and Rehabilitation in response to the subject subpoenas (other than documents produced pursuant to section 6603(c)(1); and 3) issue an order permitting the medical staff of CHS to disclose confidential health information to the extent permitted by section 6603(c)(1).