Ratcliffe and Taniguchi (2008) 'CCTV Camera Evaluation'. Temple University, Philadelphia PA.

The crime reduction effects of public CCTV cameras in the City of Philadelphia, PA installed during 2006.
Crime in the vicinity of CCTV cameras is examined using two different evaluation techniques. A multilevel model that considers long-term trends and seasonality finds that the introduction of cameras is associated with a 13 per cent reduction in crime. A site-specific examination of each camera location finds that while some cameras reduced reported crime and spread a benefit to the surrounding area, other cameras failed to prevent reported crime or appeared to displace more crime to surrounding streets than they prevented.
Published 7th February 2008. Authors: Jerry Ratcliffe and Travis Taniguchi