Evidence-Based Policing Matrix
Micro Places – La Vigne et al. (2011)
La Vigne, N. G., Lowry, S.S., Markman, J. A., & Dwyer, A. M. (2011). Evaluating the use of public surveillance cameras for crime control and prevention. Baltimore case study. Washington, DC: Urban Institute.
Location in the Matrix; Methodological Rigor; Outcome:
Micro places, General, Proactive; Rigorous; Mixed findings
What police practice or strategy was examined?
In Baltimore, the public surveillance program cameras grew from a pilot project of five cameras to more than 500, installed downtown and in high crime neighborhoods. Cameras were monitored around the clock by a team of trained retired police officers. Officers used the cameras for special events, routine patrol activities, and undercover investigations. The cameras were used in sting operations, during which undercover officers staged a purchase of drugs in sight of the cameras, hoping to secure a conviction with visual proof of the defendant committing a crime.
How was the intervention evaluated?
The study collected data on the ways the cameras were employed and analyzed quarterly crime data from 2003 through April 2008, with the intervention date occurring during the second quarter of 2005. The researchers also examined crime trends in similar comparison areas (matched on historical crime volume, geographic location, land use, and demographics of the area) that did not receive cameras. Crimes examined included seven crime categories: all crime, violent crime, inside larceny (thefts occurring inside businesses), outside larceny (thefts occurring in open spaces), motor vehicle theft, burglary, and robbery. The net costs and benefits of camera implementation and use were analyzed as well.
What were the key findings?
In one neighborhood, results indicated a significant 15% decrease in all aggregated crime following camera installation. In another neighborhood, results indicated a significant decline in total crime, with average monthly crime counts decreasing by nearly 35%. In a third neighborhood, however, there was no significant crime reduction. (Downtown cameras showed the most positive results, but had no comparison group and so were not included here.) Even accounting for the fact that no impacts on crime were identified in one of the four study sites, the results of the cost-benefit analysis of Baltimore’s camera system indicate that Baltimore’s monthly benefits from averted crime are greater than its monthly costs. Societal savings associated with crimes averted due to the presence and use of cameras exceeded the costs of the system by the 29th month following implementation.
What were the implications for law enforcement?
Police use of public surveillance cameras can be an effective and cost-beneficial crime prevention strategy, particularly when the cameras are actively monitored and well-integrated into policing operations.
Where can I find more information about this intervention, similar types of intervention, or related studies?