1. A Quick
Review of
CPTED
Strategies
(Crime Prevention
Through
Environmental
Design)
By: Russell James, J.D., Ph.D., Associate Professor,
College of Human Sciences, Texas Tech University

3. Research
Surveillance
(Will I be seen?)

4. “burglarized
houses had
less visual
access to
immediately
neighboring
houses than
did non-
burglarized
houses”
Brown, B. (University of Utah), Altman, B. (University of Utah). 1983. Territoriality, defensible space and
residential burglary: an environmental analysis, Journal of Environmental Psychology, 3(3), 203-20.

5. “Convenience stores
experienced mean
annual robbery rate
reductions after
installation of CCTV
systems (-23%);
installation of video
cameras with monitors
(-54%)”
C. Casteel (UCLA) & C. Peek-Asa (UCLA). 2000. Effectiveness of crime prevention through
environmental design (CPTED) in reducing robberies. American Journal of Preventative
Medicine, 18, 99-115, p. 110

6. Office beverages
available with
payment on an
“honor” system.
Picture above
payment
instructions
rotated weekly.
Payments were
higher when
picture of eyes
was posted.
M. Bateson, D. Nettle & G. Roberts (2006). Cues
of being watched enhance cooperation in a real-
world setting. Biology Letters 2, 412–414.

7. Two groups with two computer backgrounds. Each
person receives $10. Computer question: Do you want to
share any of it with another (anonymous) participant?
A B
K. J. Haley (UCLA), D.M.T. Fessler (UCLA). 2005. Nobody’s watching? Subtle cues affect generosity
in an anonymous economic game. Evolution and Human Behavior, 26, 245–256

8. Normal Eyes Screen
Screen
Not
Sharing
12%
Not
Sharing
45%
Sharing
55%
Sharing
88%
K. J. Haley (UCLA), D.M.T. Fessler (UCLA). 2005. Nobody’s watching? Subtle cues affect generosity
in an anonymous economic game. Evolution and Human Behavior, 26, 245–256

9. Research
Access
(Can I get in and out)?

10. “Burglarized houses had fewer
fences and locked gates
surrounding the yard than did
non-burglarized houses.”
Brown, B., Altman, B. (1983). Territoriality,
defensible space and residential burglary:
an environmental analysis, Journal of
Environmental Psychology, 3(3), 203-20.

11. Preventing access by adding chain link fencing
and lighting to lower levels of this parking
garage led to 50% drop in reported crime.
Tseng, C.-H. (Ohio State U.), Duane, J. (Ohio State U.), &
Hadipriono, F. (Ohio State U.). 2004. Performance of
Campus Parking Garages in Preventing Crime. Journal of
Performance of Constructed Facilities, 18(1), 21-28.

12. Research
Territoriality
(Does anyone care
what happens
here?)

13. “burglarized houses had fewer symbolic
barriers characteristic of primary
territories (i.e., fewer markers depicting
the identity of the territory owners)”
Brown, B. (University of Utah), Altman, B. (University of Utah). 1983. Territoriality, defensible space and
residential burglary: an environmental analysis, Journal of Environmental Psychology, 3(3), 203-20.

14. In a study of 400 convenience store robberies, one
significant difference between robbed and non-
robbed stores was distance from nearest graffiti
S. A. Hendricks, D. P. Landsittel, H. E. Amandus, J. Malcan, & J. Bell. (1999) A matched case-
control study of convenience store robbery risk factors. Journal of Occupational and
Environmental Medicine, 41(11), 995-1004

15. S
urveillance
(Will I be seen?)
A ccess
(Can I get in and out)?
T erritoriality
(Does anyone care what happens here?)

16. Will I be seen?

17. Surveillance: FAIL

18. Can I get in and out?

19. Access: FAIL

20. Does anyone care what happens here?

21. Territoriality: FAIL

22. Does anyone care what happens here?
Territoriality: FAIL

23. Can I get in and out?
Access: FAIL

24. Does anyone care what happens here?

25. Territoriality: FAIL

26. Access: Can I get in and out?

27. Territoriality impacts Access
If no one cares what happens here, is it
less risky to try opening the door with
a crowbar or bolt cutter?

29. ACCESS: Does the fence make it harder to
get in and out?

30. SURVEILLANCE: Does the fence make it less
likely I will be seen when attempting to break in
through a back door?

31. Surveillance + Access + Territoriality may impact
each other.

32. Does anyone care what happens here?

33. The fence says “Maybe”.
Everything else says “No”

34. Does anyone care what happens here?

35. TERRITORIALITY:
High level maintenance. Defined borders.

36. Short decorative fencing can enhance
territoriality inside the fence without
disconnecting from the surrounding
neighborhood

37. Short decorative fencing can enhance
territoriality inside the fence without
disconnecting from the surrounding
neighborhood

38. Short fencing,
even if solid,
creates no
surveillance
problems.

39. As fences get higher, the access barrier
increases, but the risk of visually disconnecting
from the neighborhood also grows

40. Does anyone care
what happens here
INSIDE the fence?

41. Does anyone care
what happens here
OUTSIDE the fence?

42. High fences may
diminish territoriality
outside the fence

43. High solid fences
• Indicates lack of
territoriality
Can anyonewalls what
outside of see
happens outside the fence?
• Reduces natural
surveillance

44. High solid fences
• Indicates lack of
territoriality
outside of walls
Does anyone care what
happens outside the fence?
• Reduces natural
surveillance

45. High solid fences
• Indicates lack of
territoriality
outside of walls
High solid fences may
create spaces with little
• Reduces natural
surveillance or territoriality
surveillance

46. Some high fences
control access, but
fail the S.A.T. by
(1) Blocking
surveillance
(2) Sending a clear
message that
the area is
dangerous,
crime is
accepted, and
no one cares
what happens
outside the wall

47. Making the chain link fence opaque blocks
surveillance and permits graffiti showing a lack
of external territoriality.

48. With proper design
and maintenance,
high fences can
limit access without
damaging
surveillance or
territoriality

49. A high fence blocking access without
damaging surveillance or territoriality

50. Spikes can add a visceral
element of access
reduction that is still
decorative and residential

51. Of course, you
can go too far
with anything!

52. Window bars limit access, but may also send a
negative territoriality message about
neighborhood safety.

53. Glass block can create
security similar to window
bars but without the stigma

54. Most burglary
entries do not
occur through
the front door,
often because
of natural
surveillance.

55. Open access
to side or
rear entry
points where
there is no
natural
surveillance
make for
more
attractive
burglary
entrances.

56. Access barriers to
side or rear entrance
can reduce the risk

57. A very short barrier may provide
insufficient access control

58. As barriers rise, access
is reduced

59. Tall opaque barriers
limit access, but may
also eliminate natural
surveillance

60. The line of sight for entry points is critical.

61. Am I visible to outsiders here?

62. Am I visible to outsiders here?

63. Am I visible to outsiders here?

64. Am I visible to outsiders here?

65. Consider the
sight-lines in
this aerial shot
of a new group
of duplexes

66. Front
Entrance /
Windows
Side
Windows
Rear
Entrance /
Windows
What are the
sight lines for
the potential
entry points in
this unit?

67. 10
residences
What are the have sight
sight lines for lines to
the potential the rear
entry points in entry
this unit?

68. 16
residences
What are the have sight
sight lines for lines to the
the potential front entry
entry points in
this unit?

69. 11
residences
What are the have sight
sight lines for lines to
the potential side
entry points in window
this unit?

70. Rear Entrance / Side Entrance/
Windows Windows
Front
Entrance /
Windows
What are the
sight lines for
the potential
entry points in
this unit?

71. 2
residences
What are the have sight
sight lines for lines to
the potential rear
entry points in entrance
this unit?

72. 0
residences
have sight
What are the lines to
sight lines for side
the potential window
entry points in
this unit?

73. Zone outside
residence
where sight
What are the lines are
sight lines for covered by
the potential wooded area
entry points in with link to
this unit? walking trail

74. Which residence
has better SAT
scores?

75. What natural surveillance issue best
predicted convenience store robberies?
C. Casteel (UCLA) & C. Peek-Asa (UCLA). 2000. Effectiveness of crime prevention through environmental
design (CPTED) in reducing robberies. American Journal of Preventative Medicine, 18, 99-115, p. 110

76. C. Casteel (UCLA) & C. Peek-Asa (UCLA). 2000. Effectiveness of crime prevention through environmental
design (CPTED) in reducing robberies. American Journal of Preventative Medicine, 18, 99-115, p. 110
Visibility from outside the store to inside
the store was the most important sight line

77. C. Casteel (UCLA) & C. Peek-Asa (UCLA). 2000. Effectiveness of crime prevention through environmental
design (CPTED) in reducing robberies. American Journal of Preventative Medicine, 18, 99-115, p. 110
Visibility from outside the store to inside
the store was a more significant predictor
of convenience store robberies than the
number of clerks or the proximity to drug
traffic, gangs, or subsidized housing.

78. At night, surveillance depends on lighting.

79. Of course, surveillance can
be blocked by both darkness
and solid barriers.

80. • line of site; access out
Lighting alone may not
overcome natural barriers to
surveillance

81. Lighting can also
be important
during the day,
especially where
lines of sight are
limited

85. What signals do
you get that
territoriality
appears weak
here?

86. Closed stairwells have low natural surveillance
and easy access for both entry and escape

87. Combined with territoriality deficiencies,
stairwells can create CPTED problem areas.

88. Design solutions
can improve the
natural
surveillance for
stairwells

89. Open stairwells
have strong
natural
surveillance
properties

90. All ranges of
natural
surveillance
levels are
possible for
stairwells
depending upon
the design
solution chosen

91. “replacing bathroom entrance doors
with right-angle entrances permit the
warning sounds of crime to travel more
freely and reduce the sense of isolation”
Sommer, R. (1983). Social design: Creating buildings with people in mind. Englewood Cliffs, NJ: Prentice-Hall

92. Cul-de-sacs may limit access,
making visiting cars more noticeable

93. Cul-de-sacs make automobile
escape more problematic as
there is only one exit route

94. Street closures can provide
similar access results

95. Pedestrian traffic
can also be limited
with street closures

96. High rise buildings
provide weaker
surveillance of
street level activity
because of
structural
separation, distance
separation, and
sound separation.
This separation also
limits the sense of
territoriality over
street level
activities.

97. Mid rise balconies create stronger surveillance and
territoriality, connecting residents with street level.

98. Mid-rise balcony
neighborhoods
create safer
street level areas
with high levels
of perceived
surveillance and
perceived
territoriality

99. Presentation by Russell James III, J.D., Ph.D.,
Associate Professor, College of Human
Sciences, Texas Tech University.
Dr. James’ research has been published in a
variety of housing and design related
academic journals including: Environment
& Behavior; Housing Policy Debate; Journal
of Urban Planning & Development (ASCE);
Journal of Performance of Constructed
Facilities (ASCE); Housing, Theory, and
Society; Housing & Society; Journal of the
Community Development Society
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