Evidence-Based Policing Matrix
Micro Places – Circo & McGarrell (2021)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Micro places; General; Proactive; Moderately Rigorous; Mixed effects
What police practice or strategy was examined?
In 2016, the Detroit Police Department (DPD) initiated “Project Green Light Detroit” which involved installing hundreds of high-definition CCTV cameras that were integrated with the real-time crime center at dozens of businesses. The project aimed to increase police response, improve the identification of offenders, and increase cooperation between business owners and the police. Most of these businesses were gas stations, liquor establishments, restaurants, and convenience stores. The program was expected to utilize information from Green Light businesses and leverage partnerships with business owners to develop a comprehensive solution to public area crimes. Moreover, increased lighting, visible cameras, and Green Light signage were used to create a deterrent effect against potential offenders, leading tofewer reported crimes and public disorder incidents. This intervention was intended to supplement other violence-reduction programs in the city, such as Ceasefire and Detroit One.
How was the intervention evaluated?
Using a quasi-experimental design, eighty-seven businesses receiving the program were matched with a comparison group of 201 businesses that did not receive the program. Treatment and control businesses were compared using monthly crime incident reports of violence, property crimes, and disorder. Crimes within 200 feet of each business were measured. A Bayesian hierarchical linear growth curve model was employed to determine the effect of CCTV camera surveillance at Green Light businesses over the course of 2 years.
What were the key findings?
The findings were mixed. Green Light businesses experienced an immediate but transient increase of nearly 40% which return to near baseline levels by 2017 in property crime reports. Over time, property crimes and disorder decreased faster by about 2.5% per month relative to the matched controls. However, there was little evidence of any impact on violent crimes. Much of the change in disorder crime and property crime reports occurred at gas stations.
What were the implications for law enforcement?
The authors suggest that integrated CCTV programs may increase the reporting of minor crimes that may not have been reported before. However, these programs may not likely impact violent crimes. A unique feature of the Green Light program was the promise that the Detroit Police Department would treat all calls for service high priority—giving business owners a greater incentive to call police when activity was detected. They also note that tying proactive response and patrol to participating businesses can place higher human resource costs on police departments.
Where can I find more information about this intervention, similar types of intervention, or related studies?