ABSTRACT
This chapter examines the legal definition of terrorism that policing agencies use during investigations to assess if an act is one of terrorism. The main focus of this chapter is an examination of the United Kingdom, European Union (EU), Canadian and US legal definition. This chapter also demonstrates how much of a catalyst the Al Qaeda attack on the United States on September 11, 2001, has been on Western states introducing legislation that on the whole is comparable between the respective states. Comparability in the law is important in relation to intelligence exchange and cooperation between the states’ counterterrorism agencies. While minor differences exist regarding the rules of evidence in the judicial process of the respective jurisdictions, compatibility in the law allows the information obtained and used by the agencies’ officers in one state, a degree of admissibility in the trial in a different state’s court.
