Intelligence and security informatics (ISI) is concerned with the study of the devel- ment and use of advanced information technologies and systems for national, inter- tional, and societal security-related applications. The annual IEEE International Conference series on ISI (http://www. isiconference. org/) was started in 2003. In 2006, the Workshop on ISI (http://isi. se. cuhk. edu. hk/2006/) was held in Singapore in c- junction with the Pacific Asia Conference on Knowledge Discovery and Data Mining (PAKDD 2006), with over 100 contributors and participants from all over the world. This would become the start of a new series of ISI meetings in the Pacific Asia region. PAISI 2007 (http://isi. se. cuhk. edu. hk/2007/) was then held in Chengdu, China. PAISI 2008 (http://isi. se. cuhk. edu. hk/2008/) was held in Taipei, Taiwan, in conjunction with IEEE ISI 2008. PAISI 2009 (http://www. business. hku. hk/paisi/2009/) was held in Bangkok, Thailand, in conjunction with PAKDD 2009. These past ISI conferences and workshops brought together academic researchers, law enforcement and intel- gence experts, information technology consultants and practitioners to discuss their research and practice related to various ISI topics. These topics include ISI data m- agement, data and text mining for ISI applications, terrorism informatics, deception and intent detection, terrorist and criminal social network analysis, public health and bio-security, crime analysis, cyber-infrastructure protection, transportation infrastr- ture security, policy studies and evaluation, information assurance, enterprise risk management, information systems security, among others.