Ongoing monitoring of the public space CCTV system will be critical for ensuring that it operates smoothly and that any problems are swiftly addressed. There are various methods for monitoring all elements of the system, including:
Oversight/steering committee—some authorities have appointed oversight/steering committees to monitor their public space CCTV system. Community members, council personnel, police, security personnel and other interested stakeholders may be represented on such a committee. The committee would be responsible for reviewing any complaints, reviewing logs maintained on people entering the control room and requesting access to images.
Internal audit—internal analysis of the system can provide beneficial insights into its operation. Many local authorities have considerable expertise throughout the agency that can be utilised to review the efficacy and functioning of the system.
External audit—some authorities utilise external consultants to conduct annual audits. These audits may include reviewing camera operation, control room functions, competencies of control room personnel, procedures associated with accessing images, communication procedures between the control room and police and systems for managing the overall operation of the CCTV system.
Evaluation—given the substantial capital and recurrent investment in a public space CCTV system, it would be expected that a comprehensive evaluation be conducted further to these regular monitoring procedures. A comprehensive evaluation will demonstrate whether the objectives of the system have been realised, whether the investment was beneficial and what might need to be altered to maximise the return on investment.
There are many issues that could be considered in an evaluation. Use of a realistic evaluation framework is one option. From this perspective, the following are some suggested evaluation considerations:
- reductions in identified target crimes in the specified area;
- changes in the type of crime and of criminal opportunities in the area;
- the number of convictions attributable to the CCTV system;
- spatial distribution of crime and evidence of geographic displacement; and
- consequences of any publicity campaigns.
Furthermore, consideration should be given to:
- establishing control groups (or areas) to measure displacement and diffusion of benefits and to enhance the power of any findings;
- conducting research over an extended period with a time series design. This involves measuring crime rates over an extended period, rather than calculating fluctuation in crime at one particular point in time. Short follow-up periods might overestimate the positive consequences of CCTV due to the anticipated benefits effect; and
- controlling for other interventions implemented during the CCTV system evaluation. CCTV systems are rarely the only form of crime prevention implemented in a particular location over a specific period. Improved street lighting, changes in police practices, crime prevention through environmental design-inspired treatments, watch schemes and other crime prevention initiatives often operate in concert. Controlling for the relative impact of each form of intervention is necessary to identify the actual effects of CCTV.
Box 15: Expert insights 3
Professor Paul Wilson suggests that 'local government must assess the effectiveness of CCTV over a range of offences in preventing and detecting crime, as well as how this affects the public's sense of security in public spaces. Ideally, this would be a cost-effectiveness evaluation comparing, where possible, CCTV with other possible crime prevention measures'.
In conducting a comprehensive evaluation, Professor Wilson suggests consideration of the following techniques:
- analysis of crime data (various offences) pre- and post-implementation of the CCTV system;
- observation of control room operations and operators;
- review of appropriate documentation, including log books of when images are requested by police;
- interviews with key stakeholders, including police, local government personnel, local residents, visitors to the area and local business owners; and
- review of costs and in comparison to expenditure on alternative crime prevention strategies.
Displacement and the diffusion of benefits
One of the key challenges facing public space CCTV systems is displacement. This occurs when offenders alter the place, the time, the crime, the perceived rewards or the way in which they undertake offending due to the CCTV system. Geographical displacement is when crime in one area moves to another in response to CCTV (or other crime prevention measures). An evaluation should look to establish evidence for any geographical displacement, as this might be an unintended negative consequence that produces no net reduction in crime.
Conversely, evaluators should also be alert to the potential for reductions in crime beyond the area covered by a public space CCTV system. Studies have shown that areas not covered by a CCTV system have enjoyed crime reductions due to would-be offenders believing that the system operates in a wider area than it actually does. This is known as a diffusion of benefits and requires data capture beyond the specific area in question.