The proposed Second Symposium on Intelligence and Security Informatics (ISI-2004) aims to provide an intellectual forum for discussion among usually disparate communities: academic researchers in information technologies, computer science, public policy, and social sciences; local, state, and federal law enforcement and intelligence experts; and information technology industry consultants and practitioners. The speakers and attendees, including noted informatics, computer science, and policy researchers as well as progressive leaders in law enforcement and security communities will engage in productive dialogue and explore avenues of collaboration. The organizers of the meeting will solicit high-quality research papers of relevance to intelligence and security research, which will be evaluated by appropriate researchers and practitioners for presentation as well as publication. Active intelligence and security informatics research can and will improve knowledge discovery and dissemination, and enhance information sharing and collaboration across law enforcement communities; the Second ISI Symposium supports that outcome.