Lighting & Crime

Extra lighting is often assumed to reduce crime without question. However, this is not the case. Some lighting is so poorly designed or installed that it can actually encourage crime. On this page, we discuss if any connection exists between crime and lighting, through examples.

This page includes...

• Lighting, crime and the CfDS
• How lighting can aid crime
• Lighting does not reduce crime: The evidence
• Darkness does not increase crime: The evidence
• Lighting does reduce crime: The evidence
• "Security" floodlighting
• Advice
• Conclusions
• Related links & News stories

Lighting, Crime and the CfDS

CfDS is a campaign for quality lighting. The Campaign acknowledges the need for lights at night, and we do not suggest switching off any necessary, unobtrusive light.

What CfDS campaigns against is the misuse of lighting. Lights should be no brighter than needed, and they should only illuminate the area needed to be lit for the time necessary - not neighbouring areas and the night sky. If street lighting is present, it should be just that: illuminating only the street, and not shining into people's homes without their permission, or above the horizontal. In cases where the majority of residents vote against the introduction of lighting for whatever reason, their wishes should be respected. In a democracy, those who want to light their own premises cannot be denied the right to do so. But equally, those who do not want any light to shine onto their premises should also have their rights respected.

How lighting can aid crime

• Most crime, especially domestic break-ins, occur in daylight, proving that light can aid criminals.
• Over-powered lights, shining outwards, can hide criminal activity with glare (see our floodlights page), providing ideal cover for a burglar at night by blinding potential witnesses
• Lighting can help criminals survey an area and minimise any risk, helping them to be quick and quiet.
• Lighting can highlight potential targets, "easy pickings", security lapses and escape routes
• PIR activated floodlights are so frequently triggered that they are ignored by neighbours

Lighting does NOT reduce crime: The evidence

From Britain...

• "The principal conclusion is that no evidence could be found to support the hypothesis that improved street lighting reduces reported crime.", from The Influence of Street lighting on Crime and the Fear of Crime (Crown Copyright 1991).

  "The very wide extent of the study, covering some 3500 new street lights introduced over a period of nearly three years, was unprecedented in the UK. The change in street lighting standard was considerable; typically a four-fold increase in the intensity of lighting was achieved, with more lighting columns and white light sources being introduced throughout.

  "The main database for the study consisted of over 100,000 reported crimes, although analysis was principally focused on some 9500 allegations in the most relevant locations and time periods. The area studied, an inner London Borough, has a high crime rate in a national context and thus represented a fair test for environmental crime prevention measures. In short, if street lighting does affect crime, this study should have detected it.

  "Although some areas and some crime types did show reductions in night-time crime relative to the day-light control, the dominant overall pattern, from which this study draws its authority, was of no significant change. Some further work, investigating possible contemporary influences of policing initiatives and neighbourhood watch schemes together with street lighting, provided no additional explanation of the crime pattern."

• According to the UK Government's Home Security & Crime Reduction website:
  • "Harsh, glaring floodlights are not a deterrent to criminals;"
  • Floodlights can increase the fear of crime amongst the most vulnerable
• "Better lighting by itself has very little effect on crime.", a quote from The effect of Better Street-lighting on Crime and Fear: A review, by Malcom Ramsay of the UK's Home office.
• The Association of British Insurers do not recommend outdoor lighting as a crime deterrent. Indeed, insurance companies do not offer a reduction in your premiums if you have "security" floodlights, due to the lack of evidence to suggest that lighting reduces crime.
  
• A quote from The Times newspaper (June, 2005): Toddler tear-aways targeted
  "Measures such as CCTV, increased street lighting and longer custodial sentences were judged in the report to have been expensive failures, with only a few exceptions."
  
• From the Guardian newspaper: Bright lights 'do not deter criminals'. "Over-anxious Britons are placing a blind, almost medieval, faith in brighter street-lamps and security lighting as crime deterrents, according to a statistical analysis... published in the British Journal of Criminology. "
  
• A survey by the UK Home Office "Decision-making by house burglars: offenders' perspectives" (available at the Home Office website; you can download the pdf document here), presented the following results. Based on a sample of 82 offenders, the percent of respondents rating the following factors as a deterrent are:
  
  • Belief that house is occupied (84%)
  • Presence of alarms outside property (84%)
  • Presence of CCTV/camera nearby property (82%)
  • Apparent strength of doors/window locks (55%)
  • Other factors include convenient approach and exit routes and there being a ready market for the goods.

  Nowhere in the report is the presence of lighting mentioned as a deterrent. Outdoor lights provide no information about the occupancy of a house, the biggest factor that influences a criminals' decision to break into a house. However, leaving a light on indoors implies that a house is occupied, which is more off-putting to a potential intruder and is 5-40 times more efficient (12W-100W bulb as opposed to an outdoor 500W bulb).

From overseas...

• When lighting was increased in Chicago "...there was a 21 percent increase in reported evening incidents that occurred in alleys" (the full report is available as a PDF).
  The authors conclude: "These findings indicate that, during the study period, there did not appear to be a suppression effect on crime as a result of increased alley lighting. In fact, it appears that with the increased lighting came an increase in the number of crimes reported to the Chicago Police Department."
• In 1996, the National Institute of Justice in the USA published an assessment of crime and violence in Preventing Crime: What Works, What Doesn't, What's Promising. The study found little support to the misconception that "brighter is safer", and even suggested that poorly designed lighting might actually increase personal vulnerability. The report states:
  
  • "The problematic relationship between lighting and crime increases when one considers that offenders need lighting to detect potential targets and low-risk situations. Consider lighting at outside ATM machines, for example. An ATM user might feel safer when the ATM and its immediate surrounding area are well lit. However, this same lighting makes the patron more visible to passing offenders. Whom the lighting serves is unclear."
• Lots of lights "..meant lots of glare, which in turn increased fear of crime." (taken from Boyce, P. R., Eklund, N. H., Hamilton, B. J. and Bruno, L. D. (2000) "Perceptions of safety at night in different lighting conditions". Lighting Research and Technology, 32(2), 79-91.)

Darkness does not increase crime: The evidence

• Des Moines Register newspaper, USA: Darkened streetlights fail to raise crime rate. "A money-saving decision to turn off thousands of Des Moines street- lights met with dire predictions from critics who warned that darkened streets would create a haven for crime. Statistics tell a different story. The first four months of 2004 saw a 3.5 percent drop in vandalism, burglary and robbery..."
• Belgium celebrates an annual Night of Darkness celebration, where local councils and business switch off part of their outdoor lighting. At the same time, public events are organised on the theme of the night. In 2005, around 20,000 people participated in the celebration. In the streets where lights were turned off, no crime was reported. Although one car was stolen from a street where the street lights remained on.
• Detroit, Michigan, a city with one of the highest crime rates in the USA, experienced fewer police calls than normal during the power failure of August 2003, which lasted through the whole night. Officials stated that: "Police had fewer calls within the city of Detroit than an average day, even with the blackout."
  
• "Outdoor Lighting Principles for Australia" shows how crime was cut drastically during a period of power cuts
• the IDA's "Dark Campus" program reduced vandalism on school campus' by turning of the lights when there were not required. One UK school caretaker said "...lights encourage break-ins. With the best will in the world it is impossible to guarantee that every window is securely closed in every room in a school with many builds spread over a large site."

Lighting does reduce crime: The evidence

If new, efficient non light-polluting (e.g. full cut-off) lighting were proved to reduce crime, it would be a boost for the Campaign for Dark Skies who have been arguing the benefits of efficient lighting for many years. Some have suggested that improved street lighting could prevent crime by improving visibility and so increasing perceived risk, and also by encouraging public street usage which intensifies natural surveillance. To date, however, evidence to support the idea that lighting reduces crime remains far from conclusive. Here is some of the evidence collected thus far that is used by many to argue that lighting may reduce crime.

• In Home Office Research Study 251, Effects of improved street lighting on Crime: a systematic review by Farrington & Welsh [available as a pdf] the following conclusions are drawn:
  • The results of 8 American studies are mixed. "Four studies found that improved street lighting was effective in reducing crime, while the other four found that it was not effective. It is not clear why the studies produced different results, although there was a tendency for effective studies to measure both day-time and night-time crimes and for ineffective studies to measure only night-time crimes."
  • "Five more recent British evaluation studies met the criteria for inclusion in the review. Their results showed that improved lighting led to a significant 30 per cent decrease in crime."
  • "Since these studies did not find that night-time crime decreased more than day-time crime, a theory of street lighting focusing on its role in increasing community pride and informal social control may be more plausible than a theory focusing on increased surveillance and increased deterrence."
  
  

  It should be kept in mind that:

  1. HORS251 states that crime fell only when day-time crime figures are included. If only night-time crimes are studies, lighting is regarded as "ineffective".
  2. the Bristol evaluation is concluded to be a success, even though night-time robberies increased by over 50%, when robberies in the control area actually fell by 28% (see HORS251 table 3.5; indeed, the author of the original research, Shaftoe 1994, did not claim any crime reducing effect of lighting, even though Farrington & Welsh do)

• In "The cost benefits of improved street lighting, based on crime reduction" published in Lighting Research & Technology, Volume 33 Number 1 (2001) Painter & Farrington investigated the effect of new street lighting on crime in Dudley and Stoke-on-Trent and showed that"crimes decreased by 41% in the experimental area [Dudley] with a 15% decrease in the control area" and "In Stoke, crimes decreased by 43% in the experimental area and by 45% in two adjacent areas"



It should be noted that:

1. Crime fell more in the area where there was no "improved" lighting
2. Crime fell both at night and during the day
3. According to Shining a light on evidence-based policy: street lighting and crime, the data show large variations, making any statistical conclusions inherently uncertain (due to a statistical artifact known as over-dispersion). See also Investigating whether a crime reduction measure works.
4. Only two areas were included in the survey, and only at two instances in time. This makes occurrence of an one-off variation impossible to exclude.
5. The research was sponsored by Urbis Lighting, and not an unbiased source of funding.

Both these research papers indicate, primarily by the fact that crime fell both at night and during the day, that some other factor is reducing crime, not the lighting. The most prolific offenders commit, on average, 200 crimes per year [source: BBC News], and so the reduction in crime is more likely to be caused by the arrest of such a prolific offender. Such an occurrence was not investigated in either report.

The fact that levels of crime can vary remarkably over time (maybe due to prolific offenders being arrested and released) makes statistical analysis of the impact of lighting difficult and unreliable. Such problems are discuss in the BBC Radio 4 program More or Less [available as a RealPlayer Audio file; light and crime is discussed from 10m30s to 15m40s]

"Security" floodlighting: The problem of glare and shadows

For more details about floodlights, please see our "security" floodlights page. But briefly...

The Parliamentary Select committee on Science and Technology in October 2003 called for an end to the retail of 500W "security" lights, and for the nuisance that they cause to be classified as actionable in law.

The so-called "security" floodlights, with excessive 500W bulbs in them, damage the vision of both potential witnesses of crime and CCTV cameras, with their blindingly powerful light. Floodlights need to be pointed directly downwards - even the slightest angle will render a security light useless, partly due to the excessive wattage used.

To put a 500W bulb shining down a back garden into perspective, the Smalls lighthouse uses a 35W bulb and is visible 21 miles away! [Source: wikipedia and the BBC News]

The Advice

• Point your lights downwards, and use low power
• The Institution of Lighting Engineers, the UK's premier guideline body for lighting professionals and companies, concludes in its Guidance Notes for the Reduction of Light Pollution that for most domestic tasks, the 150w full cut off floodlight correctly positioned with no light spillage is the maximum wattage needed, and indeed recommends lower wattages.
• The Government's Home Security/Crime Reduction website states "The form of lighting currently found on the overwhelming majority of domestic locations is a 250 or 500 watt tungsten halogen floodlight controlled by a movement sensor (passive infra-red, PIR). This is unfortunate, as in many locations this is the most inappropriate form of lighting available."
• If you go out at night, leave lights on indoors instead of outdoors. Research into what motivates burglars by Bennett and Wright (1984) concluded, after interviews with 300 experienced burglars, that their main concern was whether or not the premises were occupied. As mentioned above, a survey by the UK Home Office "Decision-making by house burglars: offenders' perspectives" (available at the Home Office website; or download the pdf) showed that the belief that a house was occupied was the most off-putting to a potential burglar. Outside lighting did not figure in their list of possible deterrents. If an indoor light is on then there is a risk of somebody being at home, but outdoor lights do not state anything about the occupancy of a house.
• Martin Morgan-Taylor, of the Law Department of de Montfort University, notes that "Lights in secluded areas are just that: nobody can see what the criminal is doing, and he has a courtesy light to illuminate his activities" So consider whether highlighting an area with light will cause more harm than good. Consider a completely dark environment; someone flashing a torch around will create far more suspicion in the minds of witnesses than someone moving in a lit environment."
• Use low powered lighting. According to the US Army Corps of Engineers, security CCTV cameras that are used day and night work the best if the light contrast between the bright foreground and the dark background is less than 4 to 1, otherwise the CCTV images are dominated by glare.

Conclusions

Much better research is needed to quantify the effect of light on crime, and higher scientific standards are required - especially as large amounts of money are spent on street-lighting in the hope of a reduction in crime.

When lighting is installed, the question must be asked "Who will these lights aid the most? Criminals or witnesses?" There is still no link between lighting and crime, due to the complex human nature of the subject. Some studies show that lights lead to an increase in crime, while others do not. The only thing that we can say for certain is that the common assumption that light will deter criminals is incorrect.

Lighting should not be installed in the hope of crime being reduced. Crime will only decrease with lighting if quality surveillance will be occuring at the same time - which is why so much crime occurs in daylight. However, if more lighting is needed for other reasons (e.g. to help people use an area), then efficient street-lighting should be installed.

Remember that lighting and dark-skies need not be mutually exclusive - the use of modern efficient full cut-off lamps can light our streets well, yet make our skies darker.

Related links & News stories