Center for Security and Crime Science
The crime reduction impact of CCTV in Philadelphia
In a 2006 referendum, about 80% of Philadelphia voters indicated a desire to change the city charter and to allow for CCTV cameras to be deployed within the city . That year a pilot project involving 10 pan, tilt and zoom cameras, and 8 static cameras was implemented. Researchers from Temple University’s Center for Security and Crime Science found that after building in controls for long-term trends and seasonality, the introduction of the cameras was associated with a 13% reduction in overall crime, though the violence rate near the cameras was too low to identify a reliable violence reduction. The evaluation suggested that while there appeared to be a general benefit to the cameras, there were as many sites that showed no benefit of camera presence as there were locations with a positive outcome on crime*.
Since then over 200 public CCTV cameras have been erected across Philadelphia since late 2007.There was clearly a need for a larger study.
On the invitation of the Philadelphia Police Department, and with grant support from the National Institute of Justice, we report here the preliminary results of a statistical evaluation of the impact of those cameras on various crime types. We say preliminary because we are still in the process of completing a range of other analyses, which when combined with the work reported here, will allow us to better determine the overall impact of the cameras. This further work will include propensity matching for control sites and a test for displacement to non-camera sites.
At present we can report preliminary results of a time series analysis of the imapct of the CCTV cameras on violence, disorder, narcotics incidents, vehicle crime and burglary.
* Details of this pilot study can be found in Ratcliffe, JH, Taniguchi, T, and Taylor, RB (2009) The crime reduction effects of public CCTV cameras: A multi-method spatial approach, Justice Quarterly, 26(4): 746-770.