California criminal justice agencies need access to data in order to provide security, health care treatment, and appropriate programming, as well as to coordinate these activities with other agencies. By the same token, outside agencies — whether criminal, social service, or non-governmental — could often do their jobs more effectively with access to information generated or retained within particular criminal justice agencies. Criminal justice realignment under AB 109 has only heightened the need for inter-agency data sharing and cooperation, yet there continue to be misunderstandings about the legal framework surrounding information exchange.

This article aims to provide a basic, practical background on the legal rules relevant to information exchange, highlighting under what circumstances — and with whom — criminal justice agencies may share, must share, or must not share their information. The Article’s basic conclusion is that criminal justice data sharing is enabled by the existing legal regime.