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Defining terrorism for law enforcement

Part One of a Six Part Series

"Thus it is said that one who knows the enemy and knows himself will not be endangered in a hundred engagements."

Sun Tzu, The Art of War.


The definition of a crime dictates our response. For instance, while responding to a robbery-in-progress call, you and your partner should be formulating your tactical plans. As you receive more information, you change your plans accordingly. In addition to affecting your tactical plans, the definition of a crime may also change your investigative approach. A homicide or sexual assault investigation typically begins with the victim. A property crime, on the other hand, tends to focus initially on the scene. Even prevention methods change by the definition of crime. How many times have victims said their house was robbed? They don't mean that two men booted the door brandishing guns. They usually mean that someone jimmied the rear door and snuck in while they were away. In reality, a "burglary," not a "robbery," occurred. By properly defining the crime, we can develop and put in place methods of prevention.

This series of six articles explores terrorism and the first responder. In this introductory article, we begin by exploring the term "terrorism" with the expectation that a clearer definition will ultimately make us more effective. By the end of the series, we will have explored a variety of terrorist-related subjects, culminating with a look at how, and possibly why, terrorism has changed dramatically in the last three decades.

Beginning with the FBI's Definition

Practitioners and scholars hotly debate the definition of terrorism. From certain standpoints "one person's terrorist could be another's freedom fighter[i]." For some, terrorism is Asymmetrical Warfare, meaning a weaker opponent using unconventional tactics against a stronger, more conventional foe[ii]. In Asymmetrical Warfare, terms like "guerilla fighter," "insurgent" or "revolutionary" describe those fighting against an established government. On a national policy level, it's very important to differentiate between national liberation movements and terrorism. As a country, the United States has at times supported national liberation movements and at other times supported embattled governments. However, there are several distinguishing factors between terrorism and the actions of ordinary revolutionaries or criminals. For domestic law enforcement, it may be more important to concentrate on the difference between terrorism and traditional crime. For purposes of this series of articles, we will be exploring and building on the Federal Bureau of Investigation's (FBI) definition of domestic terrorism: "Domestic terrorism refers to activities that involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any state; appear to be intended to intimidate or coerce a civilian population; to influence the policy of a government by mass destruction, assassination, or kidnapping; and, occur primarily within the territorial jurisdiction of the United States[iii]."

Motive Makes the Difference

A primary part of this definition that separates terrorists from ordinary criminals is motive. For someone to commit a terrorist act, his or her motivation must be a social, political or religious cause. "Religious cause" is added to the definition because there is significant evidence to believe that religious motives are dramatically changing the nature of terrorism. In his study on mass casualty bombers, Quillen[iv] found "a religious motivation can be identified in not only the majority of cases (47), but also in a majority of the casualties (3,952)[v]. Thus, a street gang or members of organized crime might terrorize a neighborhood, but since their primary motive is personal gain or perhaps revenge and not a social, political or religious cause, they are not, by definition, terrorists.

A Crime is a Crime

The next critical component of the definition is the occurrence of a crime. Holding, espousing and, in some ways, acting on radical political, social or religious beliefs is not a crime. An individual or a group can hold radical political beliefs and express them in a lawful manner. A typical instance might be a lawful demonstration. In later articles, when we look closer at the difference between a terrorist incident and terrorist activity, we will see that some types of lawful activity (for instance, buying one-way airline tickets) can be an indicator of an impending terrorist incident. Instances of lawful activity supporting criminal activity are often found in the investigation of organized crime.

Fear is the Purpose

The third key component of the definition of terrorism is the intention "to intimidate or coerce a civilian population[vi]." According to Pain, "not any political extremism can be called terrorism but only that one which admits (and really practices) politically motivated violence against a civil population[vii]." Terrorists commit acts of violence against civilians in order to produce fear. Often, the savage violence and seemingly random victimization is what causes the fear, similar to that created by hate crimes. While burglary traumatizes the victim, generally it does not extend beyond their neighbors and is ultimately forgotten. If you are the victim of a burglary, you have options that decrease the likelihood that you will be a victim again. You have some power over the situation. However, "victims of hate/bias crimes are particularly sensitive and unsettled because they feel powerless to alter the situation since they cannot change their racial or ethnic status[viii]."

For both terrorist and hate crimes, everyone who is in the victim's group feels similarly unsettled because the random nature of the violence means they have an equal chance of becoming a victim. Consider, for example, that after September 11,nearly everyone who had flown on a commercial airliner thought to himself or herself about what they would have done, what it would have been like. Nearly everyone who works or visits a high-rise building had similar thoughts. It was not just the devastation and violence, but also the randomness and the normality of the locations that made us fearful. In other words, victimization was random and solely based on membership in the group being attacked - the United States of America. Any one of us could have been a victim. As Mylonaki observed, terrorism is "designed to have far-reaching psychological repercussions beyond the immediate victim or target[ix]." Like the victim of a hate crime, we are all in it together.

Looking Ahead

The definition of terrorism could be simply stated as "a crime motivated by political, social or religious beliefs that is designed to cause widespread fear." Implicit is the idea that the victims are non-combatants and the perpetrators are criminals. For domestic law enforcement, it does not matter if the victim is in uniform or the location a military/government building - a crime is a crime. Moreover, the strength of American law enforcement is its ability to respond to criminal incidents, investigate and bring the suspects to justice.

Using the definition explored in this article, we can begin to look at tactical responses, investigative techniques and prevention. Throughout this six-part series, we will be approaching the subject of terrorism through the lens of this definition in order to aid officers, detectives and police managers' effectiveness in deterring, investigating and responding to terrorism.

Parts two through six of this series will cover the following topics:

  • Homeland Security: A needs assessment
  • Lessons Learned Overseas
  • Homeland Security and the National Response Plan
  • Homeland Security and Community Policing
  • Counter-terrorism at the Local Level: What Street Cops can do


[i]Mylonaki, E. (2002). The manipulation of organized crime by terrorists: legal and factual perspectives. International Criminal Law Review (2) 213-235.
[ii]Teo Li-Wei, F. (2002). Rethinking western vulnerabilities to asymmetric warfare. Journal of Singapore Armed Forces. (28)2.
[iii]Terrorism in the Unites States (1999) Counterterrorism Threat Assessment and Warning Unit Counterterrorism Division, Federal Bureau of Investigation.
[iv]Quillen, C. (2002). A historical analysis of mass casualty bombers. Studies in Conflict and Terrorism, 25, 279-292.
[v]Quillen reviewed bombings between the end of World War II until the end of 2000. He found that mass casualty bombings (more than 25 deaths) occurred on seventy-six occasions resulting in 5,690 deaths.
[vi]Terrorism, FBI
[vii]Pain, E. (2002). The social nature of extremism and terrorism. Social Sciences, 33(3), 55-69.
[viii]Shusta, R., D. Levine, H. Wong and P. Harris (2005) Multicultural Law Enforcement. Prentice
[ix]Hall, Upper Saddle River, New Jersey.
[ix]Mylonaki, International Criminal Law Review

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