Since the attacks of September 11, 2001, law enforcement has focused a great deal of energy in deterring threats of terrorist’s attacks towards the United States and its interests. The majority of Americans agree that terrorism should be a top priority of federal and state law enforcement agencies. The issue that often arises and is heavily debated in the United States has been the way in which law enforcement agencies combat terrorist threats and the Constitutionality in which monitoring and prosecuting terrorist have been enforced. Law enforcement in the United States is learning how to defend itself against terrorist while balancing national security and civil liberties. Despite the perception that terrorism is an imminent threat to all American citizens, the reality is that federal and local law enforcement agencies are presenting, stopping and deterring terrorism internationally and domestically.