illegitimate users out of the area. The third principle of CPTED is territorial
reinforcement. Territorial reinforcement attempts to foster ownership and
responsibility of an area by legitimate users by reducing unassigned spaces.
Reducing unassigned spaces alters the perception of illegitimate users by
showing that someone is responsible for the space. Some areas, by their design,
have encouraged illegitimate users to take over the area and scared off legiti-
mate users. Property owners may implement territorial reinforcement meas-
ures to discourage the illegitimate users and over time encourage legitimate
users to return to the area.
Crime Displacement and Diffusion of Benefits
Crime Displacement
Displacement of crime is a relatively new and controversial topic in the
academic crime prevention circles. Crime displacement occurs when security
measures are effective in preventing crime where the security measures are in
place and forces the criminal to go elsewhere with less security to commit their
crimes. The security decision maker must remember that only effective crime
prevention can cause displacement.
There are six types of crime displacement: temporal, target, spatial, tactical,
perpetrator, and offender. Temporal crime displacement entails a shift in the
timing of crime to different hours of the day or days of the week when appre-
hension is less risky. Temporal displacement is one of the key reasons that
random security patrols are more effective than scheduled patrols. The ran-
domness does keep the criminals on their toes by not providing them with a
set time to commit the crime. Ta r g e t crime displacement occurs when a crim-
inal, given two equally valuable targets, will select the less risky one. Females
are typically perceived as weaker or more vulnerable than males in the crimi-
nal mind, and thus the criminal will likely select the female to victimize. Spatial
crime displacement is similar to target crime displacement with the exception
that the displacement is caused not by the actual target but by the facility itself.
An example is two convenience stores located across the street from one
another. One is well lit and has good visibility into and out of the store, while
the other is poorly lit and has signs in the windows that obstruct visibility. A
crime that may have occurred at the more secure store is displaced to the other
store. Tactical crime displacement involves the adversary changing his tactics
to commit the crime owing to the security measures that are in place. For
example, a perpetrator who finds that windows have been secured after previ-
ous attacks at a particular facility may shift tactics and find another entry point
into the facility. In perpetrator crime displacement, specific offenders are
deterred or apprehended and other offenders take their place. An example of
this type of crime displacement is law enforcement’s capture of a drug dealer
who works a certain corner in a neighborhood and whose place is taken by
Prevention 169

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