The long-term goal of a security system for information sharing is to engender trust among information managers and users that all parties with access to shared information will follow certain minimum practices that will safeguard the information. This document presents four general models for justice information sharing: the Joint Task Force Model, the Centralized Information Repository Model, the Peer Group Model, and the Justice Interconnection Services Network Model. These four models are simplified representations of the organizational relationships, computer systems, and the flow of information characteristic of the justice and public safety communities. They are illustrations of "best-of-breed" security practices. Although the models are described individually, in practice justice information systems are a combination of these models. Within these models, 15 areas of security are discussed: management; physical security; personnel security screening; separation of duties; identification and authentication; authorization and access control; data integrity; data classification; change management; public access, privacy, and confidentiality; firewalls, virtual private networks, and other network safeguards; intrusion detection systems; critical incident response; security auditing; and disaster recovery and business continuity.