Lighting & Crime
Lighting is often assumed to reduce crime without question. However, there is a growing body of evidence indicating that lights lead to no change in crime levels, or even an increase in crime. As inefficient and excessive lighting is often installed in the premise of reducing crime, here we review the latest research into the subject.
This page includes...
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.
How lighting can aid crime
The majority of crime occurs either in daylight hours or beneath artificial lights. Here are some possible explanations as to why this is the case.
- Crime usually occurs where or when there are few (if any) witnesses, and so the lighting levels are irrelevant.
- Lighting can highlight potential targets ("easy pickings"), security lapses and even escape routes - in short, light can help criminals be quick and quiet.
- Lighting can help criminals see what they are doing, minimising any risk to themselves.
- Outwards shinning lights can hide criminal activity with glare, providing ideal cover for a burglar at night by blinding potential witnesses (see CCTV scuppered by street lights, and our floodlights page).
- PIR activated floodlights are so frequently triggered that they are ignored by neighbours
The Greater Manchester Police "Designing out Crime: Parks & Public Open Spaces" document (available as a PDF document) states:
"In certain situations, lighting may aid or encourage congregation, crime and disorder. Consideration should be given to:
- Avoiding lighting in remote locations under minimal surveillance.
- Maintaining lighting to car parks and buildings, only during periods when authorised staff retain a site presence."
Lighting has no effect or even increases crime: The evidence
Thieves steal Brighton and Hove streetlamps, from the Brighton & Hove Argus (May, 2010).
"CCTV cameras in Sussex are being hampered by street lights, The Argus can reveal. Glare from lamps is causing such poor picture quality that individuals filmed committing a crime cannot be identified.", as reported in the Brighton & Hove Argus. (February, 2010)
In Essex, a trail to turn off suburban street lights between midnight and 5.30am, has been deemed a success. Police state: "A year on year comparison for April 2006 to May 2007 [when street-lights were left on all night] and April 2007 to May 2008 [when street-lights were turned off at midnight] has shown that night-time crime has almost halved in Saffron Walden and reduced by over a third in Dunmow."
For more details, read the Total Essex news article.
"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."
- The majority of crimes occur in the summer months (see "Seasonality in recorded crime" by Hird & Ruparel, available from the Home Office website as a PDF document). According to this report, although domestic burglary peaks in January, there is less domestic burglary in the dark days of February than in any of the summer months.
BBC News: Residents' Christmas lights plea
"A group of residents have offered to pay a neighbour to forgo a charity Christmas lights display which attracts hundreds of visitors. ... The lights have now been blamed for causing a "mini-crime wave". The spectators it draws have been blamed for vandalism, theft, violence and other forms of anti-social behaviour."
- 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 (2003): 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.
No-where in the report is the presence of lighting mentioned as a deterrent.
- 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."
- 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..."
- 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.)
- "Outdoor Lighting Principles for Australia" shows how crime was cut drastically during a period of power cuts
- 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."
- New York Times/San Francisco Chronicle: Light poles vanishing -- believed sold for scrap by thieves
"Thieves are sawing down aluminium light poles. Some 130 have vanished from Baltimore's streets in the last several weeks, authorities say, presumably sold for scrap metal. But so far the case of the pilfered poles has stumped the police and left many local residents wondering just how someone manages to make off with what would seem to be a conspicuous street fixture."
- 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.
- 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." See also the Peninsula School District where the "Battle Ground School District in Clark County has reduced vandalism to almost zero with a policy to darken campus after 10:30 p.m.".
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 Commission 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."
- The authors of HORS251 state that crime fell only when night-time AND day-time crimes are used together. If only night-time crimes are studied, lighting is regarded as "ineffective".
- 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 the lighting in Bristol, even though Farrington & Welsh do).
- The studies are biased due to selecting only areas of abnormally high crime. In such areas, crime would inevitably fall irrelevant of the lights being replaced. This is confirmed by the fact that crime fell more during daylight. Imagine counting an abnormally large number of cars passing by your house one day, or an unusually large amount of post; if you were to repeat the counting the following day, you would expect less cars, or less post. This statistical behaviour is known as regression towards the mean (average).
- 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:
- Crime fell more in Stoke where there was no "improved" lighting
- Crime fell both at night and during the day
- 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.
- 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.
- 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; lighting 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]
Advice & conclusions
- Always consider the possibility that installing a light may actually aid criminal activity
- Make your home appear occupied, especially during the winter months. The UK Home Office states that the main deterrent to domestic burglary is "Belief that house is occupied (84%)" (see their PDF report; the same conclusion was reached by Bennett and Wright (1984) after interviews with 300 experienced burglars). Using an outdoor PIR to activate an indoor light (such as a Byron PIR activator) will put doubt in a burglars' mind, while outdoor lights help criminals in what would otherwise be unfamiliar surrounding.
- If you need lighting to help yourself see what you are doing, ensure that you point your lights downwards to avoid blinding onlookers and potential witnesses.
- 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.
- 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."
- 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.
- 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."
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.
Lighting should not be installed in the hope of crime being reduced. Crime will only decrease with lighting if quality surveillance will exist at the same time.
When installing lighting, ask: "Who will these lights aid the most? Criminals or witnesses?"
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.