Study 1
Sivarajasingam and colleagues (2003) assessed the impact of CCTV (closed circuit television) cameras on increases in the detection of violent crime and decreases in emergency department (ED) visits for assault-related injuries.
The researchers used ED visits as a proxy for overall violence because of the close proximity of city centers and hospital facilities in most English cities (which would mean that injuries occurring in the city centers would be treated by the nearby hospital). Since other types of violence (e.g., domestic, workplace violence) would not be affected by the installation of CCTV in public spaces, a drop in overall ED visit rates was interpreted as the result of reductions in assault-related urban violence.
CCTV cameras were installed at five intervention sites: 1) Ashford, 2) Eastbourne, 3) Lincoln, 4) Newport, and 5) Peterborough. Control sites — Chelmsford, Derby, Huntingdon, Poole, and Scarborough — had no cameras. It was impossible for the researchers to match the towns/cities closely, but the five selected were from the same geographical region and had approximately the same population.
Data was collected from spring 1995 to spring 1999, which provided 2 years of data before the installation of cameras and 2 years of postimplementation data. All centers had data available. ED data was collected on assault-related visits from the hospitals. Violent offenses data related to assault and wounding was collected by the local police. No data was identifiable at the individual level. A Student’s t-test was used to examine the differences in outcomes before and after the installation of CCTV cameras. No subgroup analyses were conducted.