Closed Circuit Television Cameras (CCTV) have become an important crime prevention and security measure. Cameras collect images and transfer them to a monitoring-recording device where they are available to be watched, reviewed and/or stored.
CCTV is a situational measure that enables remote surveillance of a locale. This makes it possible for the police and other law and regulatory agencies such as private security to respond to incidents when alerted and to have information about what to look for when they arrive. The storing of images facilitates post-incident analysis that may be helpful to an investigation. There are many different types of CCTV systems and they have different capacities to meet a variety of objectives.
Despite the tendency within the criminological literature to discuss CCTV as if it were a single measure, CCTV systems can differ quite markedly. Cameras can be:
They can transmit analog or digital images via cable or wireless links. The images can be recorded in different ways with different implications for quality. The many methods of storing and manipulating images have different implications for the type and speed of monitoring that can be carried out. The availability of specialized uses such as number plate and facial recognition has generated yet more potential applications of this flexible technology.
However, the technology is only one part of a CCTV system. No system can work without a control room and there is wide variation in the way that these operate.
Control rooms can be monitored full-time or for a limited number of hours a week by a dedicated operator or by one who has other duties besides CCTV monitoring. Staffing levels vary greatly and so do the types of areas surveyed such as town centers, residential areas and parking lots. There is also a range of control room cultures, management styles and methods of communicating with the police. These factors and many others influence the way the control room operates.
Many systems also incorporate the installation or improvement of street lighting in their
design and often such improvements are made at the same time the cameras are installed. These improvements are then treated as part of the scheme design rather than as confounding factors.