"Mobile phones, the networks they connect to, the applications they use, and the services they access all collect and retain enormous amounts of information that can be useful in criminal investigations. However, state and local law enforcement face two substantial challenges when accessing these data: (1) maintaining awareness of the sources and nature of commercial data available to an investigator and (2) determining the legal rules for access to these data. This report explores these issues and describes the development of a prototype tool--the Mobile Information and Knowledge Ecosystem (MIKE)--intended to help law enforcement, commercial entities, and policy analysts explore the mobile ecosystem and understand the laws regulating law enforcement's use of data contained within the mobile ecosystem. The tool might also serve as a mechanism for sharing best practices in electronic surveillance."--Page 4 of paper wrapper.