Terrorist and transnational criminal groups have long shared similar characteristics and borrowed tactics and techniques commonly ascribed to the other. Historically examples also indicate that such groups may drift, evolve, converge, transform, or otherwise alter their ideological motivations and organizational composition to appear to mimic each other. In general, there appears to be at least three primary ways in which crime and terrorism may overlap: (1) through shared tactics and methods, (2) through the process of transformation from one type of group to their other over time, and (3) through short-term or long-term transaction-based service-for-hire activities between groups.