In Rivero v. Superior Court (1997) 54 Cal.App.4th 1048, the San Francisco District Attorney investigated a local official for misuse of public funds, but decided not to prosecute and closed its files. A year later, one of the people who initiated the investigation filed a CPRA request for the closed files. Citing the investigation exemption, Rivero refused to require disclosure, even though there was no showing of any adverse impact upon witness cooperation or evidence destruction. The requester in Rivero raised the same policy arguments as does the Times regarding a sanitized investigation, a governmental cover-up, and the need for the public to understand why government officials escaped legal sanction. The court was unpersuaded: "We observe . . . that the Legislature has amended section 6254 more than once . . . but has not revised the statute to permit disclosure of closed investigation files. We will not do what the Legislature has declined to do." (Id. at p. 1059, 63 Cal. Rptr. 2d 213.) Rivero further noted that publicity-shy witnesses could be reluctant to come forward if they knew that sensitive information they provided potentially could be turned over. "Every effort must be made to ensure that investigators can gather all evidence that is available and legally obtainable." (Rivero v. Superior Court, supra, 54 Cal.App.4th at p. 1058.)