We further estimated camera effects on counts of only incidents in public locations — street crimes.
Methods: Viewsheds, denoting the line-of-sight of CCTV cameras, were units of analysis (N = 117).
Location quotients, controlling for viewshed size and control-area crime incidence, measured changes in the levels of six crime categories, from the pre-installation period to the post-installation period.
Millions of closed-circuit television (CCTV) cameras are installed in streets and businesses throughout the world with the stated goal of reducing crime and increasing public safety. Chicago reportedly has at least 15,000 cameras installed in one of the largest U. networks — which has prompted civil liberties groups to express strong concerns — while in New York, cameras are increasingly found both on public transit as well as in businesses and even high-end residences.
We assessed camera impacts by analyzing monthly counts of crime and disorder-related calls for service that occurred within each camera’s 150-foot viewshed as an interrupted time series, with the interruption at the time that the camera in question was activated.