nformation systems solving knowledge problems are made available to knowledge workers and knowledge seekers. Artificial intelligence is applied in these systems. Expert systems, decision support systems, document management systems, intelligent search engines, and relational database tools represent some of the technologies and techniques developed to support Stage 4. Officer-to-application systems will only be successful if they are built on a thorough understanding of law enforcement. Therefore, this chapter concentrates on presenting two important knowledge application tasks in police investigations: profiling and “cross+check.” Offender profiling and cross+check in police investigations are examples of law enforcement work that can benefit from technologies such as artificial intelligence, knowledge-based systems, and case-based reasoning systems (Becerra-Fernandez, Gonzalez, & Sabherwal, 2004).