Closed circuit television does not reduce violenceBMJ 1999; 318 doi: https://doi.org/10.1136/bmj.318.7200.1717 (Published 26 June 1999) Cite this as: BMJ 1999;318:1717
Closed circuit television in city centres had no obvious influence on the level of assaults recorded in inner city hospitals' accident and emergency departments in Wales, according to research based on studies at three large hospital units. The research also showed that accident and emergency departments were better barometers of levels of violence in the community than police records.
The levels of violence were studied two years before and two years after the installation of 24 hour closed circuit television surveillance in the mid-1990s. In all, 22442 cases of assault among patients presenting at accident and emergency departments were recorded for the three cities surrounding areas, whereas only 3228 violent offences were recorded by police. Accident and emergency departments' records showed a drop of 1%in level of violence two years after closed circuit television was installed, compared with a 9%reduction shown in police records (Journal of Accident and Emergency Medicine 1999;16:255-7).
“Theoretically, installation and surveillance by means of closed circuit television would not only increase the risk of an offender being caught and therefore act as a deterrent, but also enhance the perception of the location as being safer in the public mind,” said the authors from the Violence Research Group at University of Wales College of Medicine. They suggested that because most violence is known to be concentrated in town and city centres, the research would have been expected to identify any clear changes after installation of closed circuit television. But, they added: “Overall, accident and emergency department data does not suggest that closed circuit television installation reduced town and city centre violence.”
The researchers found that the three departments in the study were recording substantially greater numbers of assaults than the police—a 10-fold difference in two of the areas, Cardiff and Swansea, and a threefold one in the third centre, Rhyl. They suggested that one explanation for the reduction in police recording may be that violence has shifted out of sight of the cameras.