Evaluating CCTV - a proposal

Advocates of public CCTV systems locally claim benefits of "on street" CCTV in 3 areas:

  1. CCTV reduces crime
  2. CCTV catches criminals
  3. CCTV makes people feel safer.

However, after 8 years of CCTV in the district, there has still been no proper, independent evaluation of their effectiveness.

Instead, we are given claims which, on inspection, prove to be little more than wishful thinking, gross exaggeration, or downright lies.

The council is proposing to undertake a "comprehensive review" of its CCTV systems. We believe that any proposed review will prove pointless without a clear understanding of the effectiveness of CCTV. We therefore submit that a proper evaluation is central to any meaningful review.

We wish therefore to make the following proposal on this matter.

We wish here to propose a formal method of evaluating the effectiveness of CCTV in the Aire Valley, focussing primarily on the claim (1) - CCTV reduces crime.

We will also make comments on the evaluation of claims in areas (2) and (3) above.

 

(1) EVALUATION OF THE EFFECTIVENESS OF PUBLIC CCTV SYSTEMS IN DETERRING CRIME IN THE AIRE VALLEY

Although CCTV systems have been in operation in Bingley and Keighley for over 2 years, so far no proper, independent evaluation of their effectiveness has yet taken place. However, the deployment of these systems provides a unique opportunity for a straightforward evaluation.

Why the Aire Valley? Although cameras have been in operation in central Bradford since 1990, the deployment of the systems there has been piecemeal and somewhat ad hoc. It does not lend itself easily to a meaningful evaluation.

The systems in Keighley and Bingley, on the other hand, were introduced more or less at the same time (January 1996). Coverage of the town centres was fairly complete. Each area is geographically distinct. They are, therefore, appropriate targets for evaluation.

Method. It isn't possible to directly measure "deterred crime" because, of course, you can't measure crimes that never happened. It is possible though to determine probable effects by looking at changes in crime patterns and trends.

This requires a more sophisticated approach to that of simply counting selective totals of "before and after", as has been presented as evidence in the case of Bingley before now.

It requires a comparison of historical and "control" trends, and a measurement of displacement effects (geographical and functional). There already exists a useful methodology, which would make a good starting point.

We refer to the study undertaken by Emma Short and Jason Ditton of the Scottish Centre for Criminology in Airdrie, Scotland, in 1996: "Does closed circuit television prevent crime? An evaluation of the use of CCTV surveillance cameras in Airdrie Town centre".

This should be extended to include the cost/benefit analysis proposed in their conclusion (though they didn't undertake this themselves), which is a crucial measure of overall effectiveness.

We propose parallel analysis be undertaken for the KEIGHLEY, BINGLEY and SHIPLEY areas from 1993 (following police area reorganisation) to the current time.

This will provide:

(a) Historical trends for comparison.

(b) "Control" trends (Shipley).

It will also provide the basis for ongoing future analysis, including the new system in Shipley.

In each case detailed crime beat statistics for each area will be needed. These are collated and kept by the police locally. The police in Bingley and Keighley have previously expressed to the council their willingness to assist any proposed research.

The analysis could be undertaken by a criminologist supported by a statistician.

(2) EVALUATING THE EFFECTIVENESS OF CCTV SYSTEMS IN CATCHING CRIMINALS

This is simply a matter of listing details of those occasions where:

(a) CCTV evidence has been used in court and has played a major or significant part in securing conviction.

(b) Conviction has been secured following a guilty plea, but it is accepted in court that CCTV evidence played a major or significant part in achieving the guilty plea.

 

(3) EVALUATING THE EFFECTIVENESS OF CCTV SYSTEMS IN REDUCING THE FEAR OF CRIME

This is also difficult to assess. In the past simple opinion surveys have been conducted which asked, in effect: "Do you think that CCTV will make you feel safer?"

But this only produces a measure of people's expectation, not their actual experience. It can also be criticised for being "explicit" about its intentions ("blind" surveys are preferred). The Shipley centre survey is perhaps a good example of the worst kind of practice - in that case subjects were "briefed" as to the benefits of CCTV before being questioned.

It is possible to carry out experiments to measure peoples actual physiological responses when walking across parts of town, but this is probably too involved for this review.

However, It should be possible to devise a "blind" survey where the actual intent is not explicit. For instance, subjects could be asked to identify those parts of the town centre where they felt safest, or most at risk. Once again, a "control" sample would be needed from an area not covered by CCTV.

(for 1 in 12 Club/Bradford TUC, May 1998)


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