Evidence-Based Policing Matrix
Neighborhood – Roman et al. (2005)
Roman, C., Cahill, M., Coggeshall, M., Lagerson, E., & Courtney, S. (2005). The Weed and Seed Initiative and crime displacement in South Florida: An examination of spatial displacement associated with crime control initiatives and the redevelopment of public housing. Washington, DC: Urban Institute, Justice Policy Center.
Location in the Matrix; Methodological Rigor; Outcome:
Neighborhood, General, Proactive; Moderately rigorous; No evidence of an effect
What police practice or strategy was examined?
The study evaluates a gang-related crackdown conducted in Miami as part of the Weed and Seed Initiative, a community-based, multi-agency approach to law enforcement, crime prevention, and neighborhood restoration aimed establishing permanent communication and partnership among stakeholders, as well as providing additional resources and support for the strategy. In January 1999, a gang-targeted crackdown was initiated by the Weed and Seed initiative in conjunction with a Safe Street Task Force that consisted of multiple law enforcement agencies. The key focus involved the dismantling of two gangs that were heavily involved in violent and drug crimes in Miami. Twenty-six arrest warrants were executed; 21 of the wanted offenders were successfully apprehended and incarcerated, and most were sentenced to life in prison. The arrests concluded an 18-month investigation targeting members of the two gangs. These efforts culminated in the convictions of 38 gang members in total.
How was the intervention evaluated?
The evaluation focuses on the impact of the arrests of 21 gang members on drug activity and violence, using crime data from the Miami-Dade County Police Department. The evaluation looked at changes in crime in the target area (roughly two square miles in size), a buffer area outside the target area, and a comparison area that did not receive the intervention. The target area included several grids in the city where the crackdown took place; the buffer area included the rest of the city; and the comparison area consisted of areas directly contiguous to the buffer area outside the city but within the county. Interrupted time series analyses were conducted on 96 monthly counts of drug and violent crime (1995-2002), half before and half after the gang crackdown intervention, for the treatment, buffer, and comparison areas.
What were the key findings?
Violent crime and drug activity in the target area did not significantly decrease as a result of the crackdown. The effect on violent crime was in the expected direction (a decrease), but the decrease was not statistically significant. Drug activity significantly increased in the target area for a 3-month period after the initial arrests of gang members in 1999. There was no evidence that crime was displaced outside of the target area, as the buffer and control areas actually experience significant reductions in violence.
What were the implications for law enforcement?
The authors suggested that the increase of drug-related crime in the target area may have reflected police prioritization of this type of offense; hence, the police may have been detecting more drug crime than before the intervention. The authors also speculated that the arrests of the gang members could have contributed to the significant reductions in violence in the buffer and control areas (if, for example, the arrested offenders lived and offended in those areas), but this could not be shown conclusively.
Where can I find more information about this intervention, similar types of intervention, or related studies?
- All studies in the Matrix on neighborhood
- CrimeSolutions.gov review of the study
- More information on Community Policing
- Gill et al.’s systematic review on community policing
- The COPS office