Counterterrorism specialists and law enforcement agencies are interested in the long-term intent or plans of the terrorists and Organized Crime members that they oppose. They often get only sporadic, incomplete, or seemingly unrelated second-hand information upon which to base their reasoning.. Some aspects of terrorist behavior are quite repetitive and regular, while terrorists go to great lengths to change and/or hide other aspects of their activity. In order to discover terrorist plans early enough to disrupt them, counter-terrorism professionals must both understand terrorist patterns of behavior and have enough evidence to begin to detect these patterns. The question addressed here is how an automated process can support plan discovery.