In the high-profile case City of San Jose v. Superior Court, the California high court recently held: "when a city employee uses a personal account to communicate about the conduct of public business, the writings may be subject to disclosure under the California Public Records Act."
The Court explains: "The whole purpose of CPRA is to ensure transparency in government activities. If public officials could evade the law simply by clicking into a different email account, or communicating through a personal device, sensitive information could routinely evade public scrutiny."
If you need information from a public agency, be sure your request appropriately includes relevant electronic information that might be stored on officials' or employees' private devices.