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  • 1. Crime and Lighting
    A misunderstood relationship
  • 2. Crime: the child of shadows
    Popular understanding of crime suggests a positive relationship between crime and darkness.
    Like so many other popular beliefs about crime, this is wrong.
    Crime most commonly occurs in the shadows, and for there to be shadows, there must be light.
  • 3. A foray into criminological theory
    Rational choice theory: criminals are reasoning actors who weighs means and ends, costs and benefits, and makes a rational choice (1997).
    Routine activities theory: Crime depends on the opportunities available. If a target is not protected enough, and if the reward is worth it, crime will happen (Cohen and Felson,1979).
  • 4. Crime Prevention Studies
    Routine activities theories has led to a number of crime prevention studies that form the basis for this presentation.
  • 5. Two factors increase security
    Security is enhanced by target hardening. Difficult or dangerous targets/victims deter (dog, alarm, well secured).
    Security is enhanced by the presence of capable guardians (police, security, active owner, noisy neighbors).
  • 6. Ineffective lighting increase crime
    According to Routine Activity Theory using lighting for safety's sake is only beneficial if you have someone to watch the lighted area.
    Extensive lighting can permit observation by potential criminals.
    Lack of light can make it difficult for criminals to assess and access their targets.
    The need for light for a prowler to see (a flashlight) can alert others to their presence.
    In most cases properly sensitized motion detectors are far more effective than always on lighting
  • 7. Improper lighting: a negative
    Poorly operating lights can in fact increase crime by creating shadows.
    Shadows shield the miscreant, while permitting them to case their target.
    Glare from improperly installed lighting can in fact hamper “guardians” from detecting predators.
  • 8. Did you know?
    Glaring light sources makes a potential victim an easier target.
    Glare light is light that travels directly from its source to a person's eye, such as a car's high beams or a poorly aimed porch light.
    Glare light requires ten minutes for night vision's sensitivity to increase a hundred fold, and forty minutes for a thousandfold sensitivity.
  • 9. Lighting Rules
    Globe lights generally are ineffective in that they generate too many shadows – permitting cover for potential offenders.
    Safety lights should be aimed at the ground (and lower wattage) so not as to compromise potential victim’s vision.
    Lights in areas which are difficult for guardians to observe (back door lights) often assist more than deter criminals.
    Motion lights are often the more effective for deterrance.
  • 10. Suggestive but limited Research
    School districts have reduced vandalism by turning out the lights (California Energy, 2010)
    Lighting of Chicago’s Alleys increased crime. (ICJIA, 2000)
    The majority of residential burglaries occur during the daylight hours (UCR, 2010).
  • 11. Conclusions
    A Recent Crime Prevention report to Congress said,“ - - the effectiveness of lighting [as a crime deterrent] is unknown. Results are mixed. We can have very little confidence that improved lighting prevents crime, particularly since we do not know if offenders use lighting to their advantage” (Sherman et al. 1998).
    “We may speculate that lighting is effective in some places, ineffective in others, and counter productive in still other circumstances. The problematic relationship between lighting and crime increases when one considers that offenders need lighting to detect potential targets and low-risk situations” (Fleming and Burrows,1986).
    Lighting is a tool for crime prevention. However as with most tools, it must be used effectively. Random use and misuse of lighting may in fact increase crime.
    While lighting does not necessarily reduce crime, it does slightly reduce fear of crime.
  • 12. References
    California Energy, 2010
    Clarke, Ronald R. (ed.) (1997). Situational Crime Prevention: Successful Case Studies. Second Edition. New York: Harrow and Heston.
    Cohen, L. E. & Felson, M. (1979). "Social change and crime rate trends: a routine activity approach". American Sociological Review, Vol 44, pp588-608.
    ICJIA, 2000,
    Keel, R. O. (1997). Rational Choice and Deterrence Theory. ttp://
    Sherman, L, et al. (1998) Preventing Crime: What Works, What Doesn't, What's PromisingNational Institute of Justice.