Skinns (1998) used a quasi-experimental design that used a process model to assess the impact of closed-circuit television (CCTV) on crime rates in Redton’s town center in England and adjoining areas. Data was collected from October 1994 through September 1995, prior to installation, and again from October 1995 through September 1996, the period after installation. Additional data was collected for the surveilled streets for a period of 30 months prior to installation to assess crime trends before cameras were installed.
Four data sets were tapped to corroborate findings:
· Police records of crime statistics
· Before/after victimization data, gathered from surveys of town center users over 16 years of age (n=1,000 for each before/after survey, with 100 percent response rate); parking garage users (n=400 for each survey, with an average response rate of 44 percent); school pupils aged 14–15 (n=69 for the before survey, n=153 for the after survey, with an average response rate of 92 percent); and business providers (n=130 for each survey, with a response rate of 60 percent)
· Attitude surveys of key workers (e.g., police officers and traffic wardens) and representatives of the public and business community
· Interviews with young offenders
Main offense categories considered included all offenses, burglary, other thefts, shoplifting, theft from a motor vehicle, theft of a motor vehicle, criminal damage, robbery, assault, sexual offenses, public order offenses, and other offenses. Analysis used two-way analysis of variance and Tukey’s method [2ANOVA(T)] and seasonally adjusted, linear regression calculations and t tests. A significance level of 5 percent was used for all analyses.
Comparison areas were constructed around the town center area to determine the extent of crime displacement or diffusion of benefits. In total, eight distinct areas were selected to help identify trends and assess the extent of diffusion or displacement. One control area was licensed premises within the CCTV area to see if crime had been pushed inside. Adjacent townships and police districts were also assessed to control for trends or displacement.