Prevention: Police Role

Ecology is a branch of the biological sciences that studies the relationships between organisms and their environment. Robert Park was the first scholar to apply an ecological perspective to social science, studying the growth of cities in the United States (Bohm). The human, or social ecological, model was later applied to criminology by Clifford Shaw and Henry McKay, who described it as the "social disorganization" perspective. Shaw and McKay (1931) hypothesized that delinquency was not merely a product of inner personal conflicts, but of environmental factors particular to certain identifiable neighborhoods. They concluded that delinquency was the result of a "detachment from conventional groups" caused by social disorganization in certain areas of a city. Sampson and Groves (1989) retested this theory and found five indicators of social disorganization: (1) lower economic status of residents; (2) diverse ethnic backgrounds of residents; (3) frequent residential turnover; (4) high level of dysfunction in families; and (5) urbanization (Bohm, pp. 72–75). Shaw and McKay's work provided the theoretical roots of environmental criminology, which is based on the important role of the "place" or the environment in shaping crime.

In 1961, Jane Jacobs examined the relationship between physical environment and crime in her book The Death and Life of Great American Cities. Her thesis was that less anonymity and isolation would lead to a reduction in crime in urban residential areas. C. Ray Jeffrey's influential book, Crime Prevention Through Environmental Design (1971), argued that modifying specific features of neighborhood design will reduce crime. In 1972, Oscar Newman argued that communities need to establish "Defensible Space," the title of his book. According to Newman, defensible space "is a model for residential environments which inhibits crime by creating the physical expression of a social fabric that defends itself" (p. 3). Both Jeffrey and Newman suggested that modifying the architecture of urban neighborhoods would reduce crime. Given a more adequate environmental design, residents will change their behavior and defend their territory against criminals (Murray). By the mid-1970s, major demonstration projects were established to test these hypotheses. The Law Enforcement Assistance Administration funded a multi-million-dollar project to extend the concept of defensible space to other environments, such as a residential area, a transportation system, a commercial strip, and a school (Murray). In addition to their implications for architecture, engineering, and urban planning, both Defensible Space and Crime Prevention Through Environmental Design have also become well-known concepts in policing.

In 1979, Cohen and Felson proposed the "routine activities" theory of crime. They argued that crime results when three elements converge in space and time: (1) a motivated offender; (2) a suitable target; and (3) the absence of a capable guardian (Felson, 1998, p. 53). According to routine activities theory, crime is most likely to occur when these three conditions occur simultaneously in some time and place. For example, if the owners of a new car (a suitable target) leave their keys in the ignition while they run into the store (absence of a capable guardian) in a high-crime neighborhood (pool of motivated offenders), then the probability that the car will be stolen is increased. Routine activities theory has direct implications for crime prevention. To prevent crime, we must alter at least one of its "ingredients": the offender, the target, or the degree of protection or guardianship. The most effective crime prevention strategies will focus on all three of these elements.

In 1981, Paul and Patricia Brantingham combined the ideas of social ecology, social disorganization theory, crime prevention through environmental design, defensible space, and routine activities theory into a single theoretical framework with their book Environmental Criminology. According to the Brantinghams, a criminal event is the convergence in time and space of a law, an offender, and a target. Unlike most criminologists who focus on the "root causes" of crime, environmental criminologists are concerned with the criminal event itself. Environmental criminology has highlighted the significant role of the "place" in generating criminal events (Brantingham and Brantingham, p. 18).

While crime prevention strategies are implicit in the theory of environmental criminology, they are the explicit focus of situational crime prevention. Throughout the late 1970s and early 1980s, Ronald Clarke developed the situational crime prevention strategy. Rather than basing crime prevention strategies on traditional "root cause" theories, Clarke's crime prevention strategies represent an applied form of environmental criminology, focusing on practical strategies to reduce the likelihood of a criminal event. Situational crime prevention attempts to reduce the opportunity for specific crimes by permanently manipulating the immediate environment to increase the risk of crime while reducing its perceived rewards.

Situational crime prevention strategies abound. Airports installed metal detectors to prevent hijacking. Libraries and stores made it more difficult to steal books and other items by installing electronic access control inserts. Caller ID programs reduced the number of obscene phone calls by taking away the caller's anonymity (Clarke, p. 22). Observe that these practical strategies do not attempt to change the behavior of offenders; they focus solely on preventing the criminal event. Unlike many other crime prevention strategies, the police are not responsible for administering situational crime prevention. It is done by merchants, governments, architects, and others with a vested interest in reducing crime. Yet, as more police departments adopt problem-oriented policing strategies, they rely on situational crime prevention techniques to analyze and respond to various types of offenses. Environmental criminology and situational crime prevention emerged independently of the police, but both now have an important influence on the practice of policing.