Sir Robert Peel

National Crime Prevention Institute

Broken Windows (article) from The Atlantic Monthly

Crime prevention has always been at the core of law enforcement since Sir Robert Peel organized London's first police force and  published Principles of Policing:

1. The basic mission for which the police exist is to prevent crime and disorder.

9. The test of police efficiency is the absence of crime and disorder, not the visible evidence of police action in dealing with it.

The most recognized definition of crime prevention comes from the National Crime Prevention Institute:

The anticipation, recognition and appraisal of a crime risk and the initiation of some action to remove or reduce it.

Although there is general agreement that the purpose of crime prevention is to improve the quality of life through the reduction of crime, individuals involved in law enforcement and crime prevention have diverse views on mechanisms that can reduce crime. This web site will focus on crime prevention through environmental design (CPTED) and other strategies associated with the "broken windows" hypothesis. [click on When Good Spaces Go Bad for additional information on the broken windows hypothesis]

To help illustrate how CPTED works consider the three elements required for criminal activity: desire, ability and opportunity. If just one of these elements can be removed the possibility of a crime being committed can be dramatically reduced. Which of these elements is the easiest to remove?

• Desire would be very difficult to remove since it involves complex factors like hunger, poverty, drug addiction and thrill seeking teenagers. It's simply not possible to immunize people against criminal intent.
• Ability involves everyday tools like screwdrivers and hammers as well as the skills and knowledge about using them. As a college instructor, I'm continually amazed at transfer of knowledge that occurs among inmates in prison populations. Sadly, the information they are conveying is often involves learning the ability to perform criminal activity. So, like desire, removing the ability of someone to commit a crime is also not feasible. Besides... if you outlaw screwdrivers, only outlaws will have screwdrivers! (Sorry, I couldn't resist ;-)
• Opportunity is the easiest element to remove. 

Successful examples of how the opportunity element has been knocked out of the equation include the introduction of direct deposits and the requirement of exact fare for bus rides. 

• The U.S. Treasury Department and American Association of Retired Persons worked together to successfully introduce "direct deposit" to reduce mail theft of retirement checks. These organizations have not only saved money due to fewer police calls and mail theft investigations, the recipients have benefited from less downtime associated with cashing checks. 
• After bus transpiration companies implemented a strict exact fare policy, robberies and assaults to bus drivers were dramatically reduced. Unfortunately, the rates of murders, robberies, and assaults of cab drivers are still incredibly high. Why? Because taxi cab drivers carry cash to make change. Perhaps this is why taxi cab drivers experience the highest workplace murder rate.

Criminals are more than ready to exploit new opportunities that appear in society. Due to the ease of obtaining and using credit cards many new opportunities exist and have resulted in a high crime rate associated with credit card fraud. Some of these new opportunities include the seemingly daily arrival of streamlined credit card applications in the mail, the fact that 23% of the population carries 3 or 4 credit cards, and more people are writing their  personal identification numbers on their bank debit cards.  

What is CPTED?  
CPTED is the acronym for "Crime Prevention Through Environmental Design." The following definition comes from a training manual on CPTED produced by the Virginia Crime Prevention Association (VCPA). : 

The proper design and effective use of the built environment can lead to a reduction in the incidence and fear of crime and an improvement in the quality of life.

or, more to the point:

Less crime by design.

Why CPTED? Why Trees?
While criminologists continue to research the causes of crime, it's important to recognize variables that may work for, or against, crime prevention. Trees growing in urban areas are one of those variables. When trees are carefully selected and maintained they can provide many economical, ecological and societal benefits to a community. Balancing the benefits trees provide against potential conflicts with crime prevention is the focus of this web site and my research. 

 Even though our knowledge of the causes of crime is incomplete, we do know a few things about human behavior.  The environment does influence our behavior. It stands to reason that the environment also influences criminal behavior. If a crime prevention strategy is going to be successful it must incorporate environmental design in its core components. It is also important that the crime prevention strategy be inexpensive.  

Goals of CPTED
Note

 how the above definition includes recognition that a reduction in the incidence and fear of crime are equally important outcomes of CPTED.  It is particularly important that people perceive a space as being safe. Once people occupy a space they will be more likely to defend their space. Security recommendations made for an area without taking into account the purpose of that specific area often result in target hardening.

Good for Business and Limiting Liability
If there were a way that a business could improve security with a relatively small investment they would probably be very interested? Before installing security cameras, hiring security guards, and other costly measures businesses should make sure they have maximized natural crime prevention measures (CPTED). Incorporating CPTED in the early planning phases is the most cost effective approach.

The courts are already aware of classic crime prevention approaches (security guards, CCTV, etc) and will hold property owners accountable when such measures have not been installed when recommended or have been poorly implemented. It's only a matter of time before courts will become aware of "natural" crime prevention approaches (like CPTED) and hold businesses, site managers, and property owners to the same level of accountability as more traditional crime prevention strategies.
 

Three Components of CPTED
The following definitions come directly from a pamphlet published by the Virginia CPTED Committee (CPTED Tips To Enhance Security).

Natural Surveillance - increases visibility
Seeing and being seen are important aspects of crime prevention. Natural surveillance guides the placement of physical features such as windows, lighting and landscaping which affect how much can be seen. A potential criminal is less likely to attempt a crime if he or she is at risk of being observed. At the same time, we are likely to feel safer when we can see and be seen.

Natural Access Control - restricts access
Natural access control guides people entering and leaving a space through the placement of entrances, exits, fences, landscaping and lighting. Access control can decrease opportunities for criminal activity by denying criminals access to potential targets and creating a perception of risk for would-be offenders.

Territoriality - promotes a sense of ownership
Physical design can create a sphere of territorial influence that can be perceived by, and may deter, potential offenders. Defined property lines and clear distinctions between private and public spaces are examples of the application of territorial reinforcement. Territorial reinforcement can be created using landscaping, pavement designs, decorative gateways, signs, and fences.

It is possible to consider these three components conceptually distinct, but in practice there is a considerable amount of overlap. Generally, natural access control and natural surveillance fall under the umbrella concept of territoriality (Crowe, 2000).

A Fourth Component?
The National Crime Prevention Council recognizes an additional component - Activity Support. This component recognizes the importance of encouraging legitimate activity in public spaces. Constructing a pool in a public park can provide recreation for youth and increase natural surveillance as well as territoriality. Other examples of activity support include Neighborhood Watch groups, block parties, parades, and neighborhood clean-up days.

Limitations of CPTED
CPTED strategies are most successful when they inconvenience the public the least.

Battling Convenience
Many individuals increase their chances of becoming victims in the name of convenience. One example of this occurs when someone writes their personal identification numbers on their bank debit cards. 

Sorry... no checklist
CPTED is a process - NOT a checklist. Due to the large number of variables associated with CPTED, it is best approached as a process and not simplified into a checklist.

Cost of Prevention
Following a formal safety assessment by a qualified law enforcement representative, a list of recommended security modifications will be left with the property owner. Many of these recommendations will be expensive. For example, there will probably be a recommendation to install high quality security locks on all outside doors to improve access control. It is also very likely that security lighting will be recommended to improve natural surveillance at night. The cost of these recommendations can add up quickly to confront the property owner with a major obstacle preventing him from taking immediate steps to improve the security around his property. Because of this, the individual performing the safety assessment will want to be sure to include some recommendations for some basic landscape modifications like pruning. In addition to being inexpensive, the act of "doing something" allows the property owner to take immediate action and begin to participate in the CPTED process.

Conducting A Community Safety Assessment
An assessment team is assembled from a variety of members in the community based upon their ability to provide information on preventing crime in the community. The assessment team should only be consist of about four or five individuals so the team can work effectively. A typical assessment team may consist of:

• Police officer or CPTED representative (often times the leader)
• Community police officer that can provide the history of the community
• Building inspector
• Fire Marshall
• Traffic engineer
• Community leader
• Planner
• Housing manager
• Social service board
• Health department
• Educator
• Horticulturist/Consulting Arborist
  • This is the one individual often missing from assessment team. Part of the reason for developing this web site is to encourage others to include arborists and horticulturists as contributing members to crime prevention initiatives, especially when the urban environment is a concern.

How Will You Know If Crime Prevention Is Working?
How will you know if CPTED, or crime prevention in general, is working? Here are some useful indicators:

• the stability of a neighborhood
• the quality of life for the residents
• residents taking better care of their properties
• resident have control over the space
• parents supervising children
• vehicular traffic obeys traffic
• residents have good relationship with law enforcement
• active neighborhood watch program
• increase in assessed valuation of real estate
• decrease in property crime (property crime?)
• no visible signs of drug or gang activity
• decrease, or absence, or vandalism and graffiti
• increase in building permits
• increase in owner occupancy
• whether people feel safer
• appears to be kept up
• less trash
• less weeds and invasive species

Brown, J. 2002. Virginia Crime Prevention Association. Richmond, VA. Personal Communication, May 2002.

Crowe, T. 2000. Crime Prevention Through Environmental Design: Applications of Architectural Design and Space Management Concepts. Second Edition. National Crime Prevention Institute. Boston: Butterworth-Heinemann

Harris, P. 2002. Virginia Crime Prevention Association. Richmond, VA. Personal Communication, May 2002.

The Virginia Crime Prevention Association and the National Crime Prevention Council's web site, and other state and national crime prevention organizations, can be found on the links page.