CCTV
Crime prevention effects of closed circuit television: a systematic review
This document is published for archival/historical purposes. It will not be updated.
CCTV has proved a popular method employed to reduce crime over recent years. The effectiveness of CCTV has yet to be proven, however, and reports of its effective (or otherwise) implementation are frequently based on anecdotal evidence. This research report examines the results of prior evaluation studies to form a clearer picture of the crime prevention effectiveness of CCTV. The conclusion is that CCTV does have a significant desirable effect on crime, but that the overall reduction is only 4%.
Title: Crime prevention effect of closed circuit television: a systematic review
Authors: Brandon C Welsh & David P Farrington
Series: Home Office Research Study 252
Date published: August 2002
Number of pages: 68
CCTV has been implemented extensively across the UK in the past 10 years. There are numerous justifications for its installation:
Caught in the act – perpetrators will be detected, and possibly removed or deterred.
You've been framed – CCTV deters potential offenders who perceive an elevated risk of apprehension.
Nosy parker – CCTV may lead more people to feel able to frequent the places under surveillance. This will increase the extent of natural surveillance by newcomers, which may deter potential offenders.
Effective deployment – CCTV directs security personnel to ambiguous situations, which may head off their translation into crime.
Publicity – CCTV could symbolise efforts to take crime seriously, and the perception of those efforts may both energise law-abiding citizens and/or deter crime.
Time for crime – CCTV may be perceived as reducing the time available to commit crime, preventing those crimes that require extended time and effort.
Memory jogging – the presence of CCTV may induce people to take elementary security precautions, such as locking their car, by jogging their memory.
Anticipated shaming – the presence of CCTV may induce people to take elementary security precautions, for fear that they will be shamed by being shown on CCTV.
Appeal to the cautious – cautious people migrate to the areas with CCTV to shop, leave their cars, and so on. Their caution and security-mindedness reduce the risk.
Reporting changes – people report (and/or police record) fewer of the crimes that occur, either because they wish to show the [desirable] effects of CCTV or out of a belief that "the Council is doing its best" and nothing should be done to discourage it.
But there has been little evidence produced to demonstrate the effectiveness of CCTV. This study attempted to rectify this situation by examining 22 CCTV schemes that fitted the following criteria:
CCTV was the focus of the intervention
There was an outcome measure of crime
The evaluation design was of high methodological quality, with the minimum design involving before-and-after measures of crime in experimental and control areas
There was at least one experimental area and one comparable area
The total number of crimes in each area before the intervention was at least 20
Of the 22 evaluations, eleven resulted in a desirable effect on crime and five an undesirable effect. Five schemes had no significant effect, and the effect of the one remaining scheme was unclear. The effect of CCTV in most settings (city centre, public house, public transport) was mixed, however there was a clear decrease in crime in car parks where CCTV had been installed.
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Last update: Wednesday, August 27, 2008