FAQ
What is "CPTED"?
Crime prevention through environmental
design, or CPTED, is a multi-disciplinary approach to reducing
crime and increasing perceived safety. CPTED relies upon the
influence of offender behavior. It seeks to dissuade offenders
from committing crimes by manipulating the physical environment
in which those crimes occur. As a result, it relies upon an understanding
of what about the environment influences offenders.
CPTED is most effective when involving
environmental designers (e.g., Architects, landscape architects),
land managers (e.g., Park managers), community action (e.g.,
Neighborhood watch groups), and law enforcement. If any of the
four defender groups are removed it is likely that a CPTED strategy
will be less effective than it might otherwise be.
Who
Coined the Phrase & When?
CPTED, or "crime prevention
through environmental design", is the brainchild of C. Ray
Jeffery. The phrase began to gain acceptance after the publication
of his 1971 book of the same name (Beverly Hills, CA: Sage).
In recent years, it has become widely known, this due more to
law enforcement's attempt to embrace it.
Does
CPTED Really Prevent Crime?
In hindsight, C. Ray Jeffery may
sometimes wish he had opted to title his 1971 book "Crime
deterrence through environmental design". It is clear
from almost three decades of research that offenders can not
with absolute certainty be prevented from committing crimes.
This is especially true when one considers that CPTED relies
upon changes to the environment that will cause an offender to
make certain behavioral decisions. Those changes are crafted
so as to encourage offenders, and thus they deter
rather than conclusively "prevent" behavior.
Understanding the deterrence potential
of CPTED can be related to the layers of a sandwich. The more
layers of tasty ingredients that go into a sandwich, the more
flavorful the end result. With CPTED, the more diverse layers
of deterrence strategies that are employed the more likely that
an offender will be persuaded to change his or her plans.
Is CPTED
the Same as "Defensible Space"?
No. Defensible space came from the
work of architect Oscar Newman. It focuses less on directly affecting
offender decision making, and more on encouraging a defensive
or protective mindset (and thus behavior) by the public. It assumes
that changes in the physical environment can result in citizens
becoming "defenders" as they become territorial, guarding
places that matter to them. Defensible space remains a well known
though not always well understood theory. It also continues to
be at once supported by and contradicted by contemporary research.
Isn't
CPTED Another Form of Target Hardening?
While CPTED can include so-called
target hardening, it is more than just that. Target hardening
is best applied to a target that an offender attempts to enter
(e.g., a building). It is less useful in open spaces such as
parks where entry points are myriad. Target hardening is also
an "overt" tactic. It does not place much emphasis
on affecting offenders subtly or subconsciously. For example,
an alarm system is often announced through stickers on windows
or other common entry points. This explains to the offender that
1) a step has been taken to prevent the crime, 2) what that step
was, and 3) potentially the degree of difficulty that defeating
the step will entail (i.e., the quality of the alarm's manufacturer).
Is CPTED
Only for Police?
No. In fact, one might argue that
CPTED is not meant for police to so much as it is for environmental
designers. The fact that police have knowledge of offenders and
are relied upon to fight crime, coupled with the dearth of designers
who understand or practice CPTED, has meant that law enforcement
is usually the main (if not the only) group utilizing
the approach.
Who
Uses CPTED?
CPTED is used by a variety of groups.
Mostly they fall into one of four categories: environmental designers
(e.g., architects, landscape architects), land managers (e.g.,
park managers), community action groups (e.g., neighborhood watch
groups), and law enforcement groups (e.g., park rangers, metropolitan
police). However each group is not equally equipped to apply
CPTED. Instead, each has a unique knowledge base that makes it
an important information source for creating effective CPTED
strategies. Combined these groups can develop holistic plans
that influence offender behavior yet do not neglect other considerations
such as preservation of historic landscapes.