History of CPTED
El término "prevención de la delincuencia mediante el urbanismo" fue originalmente acuñado y formulado por el criminólogo C. Ray Jeffery. Un planteamiento más limitado, denominado espacio defendible, fue desarrollado al mismo tiempo por el arquitecto Oscar Newman. Ambos se apoyaron en el trabajo previo de Elizabeth Madera, Jane Jacobs y Schlomo Angel. El libro de Jeffery, "Prevención de la delincuencia mediante el diseño del entorno" se publicó en 1971, pero su trabajo no se tuvo en cuenta durante la década que comenzó ese año. Por su parte el libro de Newman, "Espacio defendible: prevención de la delincuencia mediante el diseño urbano" se publicó en 1972. Sus principios fueron ampliamente adoptados pero con éxitos y fracasos. El planteamiento de espacio defendible fue posteriormente revisado con ideas basadas en la CPTED. Newman representó esto como CPTED y reconoció a Jeffery como padre del término. El espacio defendible de Newman así mejorado tuvo mucho éxito y resultó en una reconsideración del trabajo de Jeffery, quien además continuó ampliando los aspectos multidisciplinares del planteamiento. Fue publicando estos avances hasta 1990. El modelo de Jeffery es más amplio que el Newman, que se limita al entorno construido. Posteriormente se desarrollaron otros modelos de CPTED basados en el de Newman. De ellos el más popular es el del criminólogo Tim Crowe.
Hacia 2004 generalmente se entendía la CPTED como estrictamente referida a los modelos Newman/Crowe, con el modelo Jeffery empleado más bien como un planteamiento multidisciplinar de prevención de la delincuencia que incorporaba la biología y la psicología, situación que incluso el propio Jeffery aceptó. (Robinson, 1996). Una revisión de la CPTED, iniciada en 1997 y denomina CPTED de segunda generación, adapta la CPTED a la individualidad del infractor, indicación suplementaria de que el trabajo de Jeffery ya no se considera generalmente una parte de la CPTED. En 2012 Woodbridge introdujo y desarrolló la CPTED para cárceles. Demostró que fallos de diseño permiten a los delincuentes continuar delinquiendo.
1961-1970
In this decade Elizabeth Madera developed guidelines to address citizen safety issues while working with the Chicago Housing Authority, emphasizing design features that favored natural surveillance of the environment. Their guidelines were never implemented, but they did generate the new ideas that led to CPTED.
Jane Jacobs' book The Life and Death of Great American Cities (1961) argued that urban vitality and diversity were being destroyed by urban planners and their urban renewal plans. He thus challenged the axioms of urban planning of the time: that neighborhoods should be isolated from each other; that an empty street is safer than a full one; and that the car represents a progress over the pedestrian. Jacobs was editor of the magazine Foro Arquitectónico from 1952 to 1964. She had not received specific training in urban planning, but her work emerged as the foundation of a new way of seeing cities. He sensed that the way cities were being designed made their inhabitants incapable of self-regulation. He noted that new forms of urban design undermined many of the traditional controls on criminal behavior, for example, the ability of residents to observe the street and the presence of people using the street both day and night. Jacobs suggested that the lack of "natural surveillance" in the environment encouraged crime. He developed the idea that crime increases when people do not interact with their neighbors, or only do so superficially. In Life and Death..., Jacobs defined the 3 attributes necessary to make a street safe: clear demarcation of public and private spaces; diversity of uses; and many pedestrians on the sidewalks.
Schlomo Angel was a CPTED pioneer who had the notable urban planner Christopher Alexander as a teacher. Angel's doctoral thesis, Deterring Crime Through Urbanism, (1968) was a study of street crime in Oakland, California (Oakland, California). In this thesis he states "The physical environment can exert a direct influence on crime frameworks by delineating territories, reducing or increasing accessibility through the creation or elimination of borders and circulation networks, and by facilitating surveillance by citizens and police." He also claims that crime was inversely proportional to the level of activity on the street, and that the commercial area of the city was particularly vulnerable to crime because it reduced activity, making it easier for an individual to commit street crimes. Angel developed and published CPTED concepts in 1970 in works supported and widely distributed by the United States Department of Justice (Luedtke, 1970).
1971-1980
C. Ray Jeffery, a criminologist at the University of Florida, began using the term "crime prevention through urban planning" (CPTED). The denomination gained followers after the publication in 1971 of his book with that title.
Jeffery's work was based on the precepts of experimental psychology contained in modern learning theory (Jeffery and Zahm, 1993:329). Jeffery's concept of CPTED arose from his experiences with an architectural rehabilitation project in Washington, D.C., which attempted to control the school environment for local youth. Deeply rooted in Burrhus Frederic Skinner's learning theory, Jeffery's CPTED approach emphasized the role of the environment in developing pleasurable and painful experiences for the offender that could alter the outcomes of his behavior. His initial CPTED model was stimulus-response: the organism learned from punishments and reinforcements in the environment. Jeffery “emphasized material rewards…and the use of the environment to control behavior” (Jeffery and Zahm, 1993:330). The main idea was that if the reinforcements to crime were eliminated, it would not occur.
A contribution of this book by Jeffery that has been little taken into account is the extraction of 4 critical factors for preventing crimes that have stood the test of time:.
The first 3 are susceptible to control by the potential victim, while the last is not.
For reasons that have received little attention, Jeffery's work went unheeded during this decade. The author's own explanation is that, at a time when the world wanted prescriptive design solutions, his work offered a broad theory and used it to identify a wide range of crime prevention functions that should guide design and management standards.
Concurrent with Jeffery's largely theoretical work, earlier this decade Oscar Newman and George Rand conducted an empirical study on the connection between crime and environment. As an architect, Newman highlighted specific features of the design that Jeffery had not noticed. Newman's book Defensible Space: Crime Prevention through Urbanism (1972) contains an extensive treatment of crime related to housing layout based on analysis of crime data from the New York Housing Agency. This book changed the nature of crime prevention and urban design: within 2 years of its publication, substantial federal funds were allocated to study and demonstrate the concepts of "defensible space."
As Newman established, a defensible space should have 2 components: first, it should allow people to continually see and be seen. In the end this reduces the residents' fear, because they know that a potential criminal can be observed, identified and, consequently, captured. Second, people must intervene or report when crime occurs. By increasing the feeling of security in the environments where people live and work, this second factor encourages people to take control of these areas and assume the role of owners. When people feel safe in their vicinity, they are more likely to interact with each other and intervene when crime is committed. These 2 components remain at the core of most CPTED applications.
1981-1990
In this decade it was observed that defensible space prescriptions were effective sometimes and not others. They worked best in residential settings, especially if residents were relatively free to respond to cues to increase social interaction. In contrast, in institutional and commercial settings, they were only marginally effective. As a result, Newman and others promoted the improvement of this theory by adding CPTED features. They also downplayed the less effective aspects of defensible space. Contributions to the advancement of CPTED in this decade include:
1991-2000
The book Crime Prevention through Environmental Design (1991), by criminologist Tim Crowe, provided a solid foundation for CPTED moving forward for the rest of this decade.
From 1994 to 2002, the Sparta Consulting Corporation, led by Severin Sorensen, managed the largest CPTED training and technical assistance program in public housing with the CPP certificate, funded by the United States Department of Housing and Urban Development. During this period Sorensen worked with Ronald V. Clarke and the Sparta team to develop a new CPTED "Curriculum (Education)" curriculum that used situational crime prevention as the theoretical basis for CPTED measures. This curriculum was developed and actors in the social housing environment were trained in it. CPTED follow-up assessments were subsequently carried out on several buildings. Sparta-led CPTED projects showed reductions between 17 and 76 percent of reported FBI UCR Part I crimes, depending on the set of CPTED measures applied in high-crime, low-income U.S. neighborhoods.
In 1996 Oscar Newman published an update of his CPTED work, titled Creating a Defensible Space, Institute for the Analysis of Community Design, Planning and Development Research Agency of the US department mentioned in the previous paragraph.
In 1997 an article by Greg Saville and Gerry Cleveland The second generation of CPTED urged those who applied these measures to take into account their origins in social ecology, considering psychological and social aspects beyond urban planning.
2001-2010
By 2004 the elements of CPTED had achieved wide international acceptance due to attempts to include them in laws. The term CPTED "environment" is commonly used to refer to the external environment of the site. Jeffery's intention that it also refer to the internal environment of the offender seems to have been lost, even among those who promoted, under the banner "second generation CPTED" that CPTED also encompass social ecology and psychology.
2011 onwards
In 2012 Woodbridge introduced and developed the concept of CPTED in the prison environment, a place where inmates continue to commit crimes after being convicted. Jeffery's understanding of the offender's mind in his study of a halfway house forty years earlier was now being used to reduce crime in those same types of facilities. Woodbridge showed how prison design allowed crime to continue, and introduced changes to reduce crime.