Promising - One study
Date: This profile was posted on November 15, 2012
A place-based, problem-oriented policing strategy implemented by the Boston (Massachusetts) Police Department in response to a sudden increase in violent crimes. The program is rated Promising. The results showed that the intervention had significant reductions in total violent index crimes, robberies, and aggravated assaults over the 10-year study period; however, there were no significant reductions in homicides and sexual assaults.
After a dramatic decrease in violent crime throughout the 1990s, the city of Boston (Massachusetts) witnessed a sudden rise in the number of violent index crimes (including murder, forcible rape, robbery, and aggravated assault) from 2004 to 2006. Violent index crimes rose by 9 percent during those years, while the number of homicides jumped by 23 percent. In response to the spike in violence, in 2007 the Boston Police Department (BPD), led by a new commissioner, implemented a place-based, problem-oriented policing strategy called Safe Street Teams (SST).
The SST program was designed to reduce violent crime by assigning teams of BPD officers to targeted crime hot spots around the city and requiring them to implement problem-oriented policing strategies to address specific violence-related problems at each site. Officers assigned to the SSTs were tasked with modifying the place characteristics, situations, and dynamics that promoted violence in the targeted areas.
The BPD used mapping technology (ArcGIS 9) as well as violent index crime data for the 2006 calendar year to identify 13 violent crime hot spot areas that SST officers would target. The 13 hot spots covered only 6.1 percent of Boston’s street geography but experienced 23.1 percent of the city’s violent index crimes in 2006. The targeted areas of Boston were Orchard Park, Grove Hall, Codman Square (B3), Upham’s Corner, Eagle Hill, Codman Square (C11), Bowdoin/Geneva, Franklin Field, Downtown Crossing, Heath/Centre Street, Lower Roxbury/S. End, Morton/Norfolk, and Tremont/Stuart.
There were 13 SSTs stationed at hot spots around the city. Each SST consisted of a sergeant and six patrol officers. The SSTs were responsible for employing community- and problem-oriented policing techniques, such as the SARA (scanning, analysis, response, and assessment) model. All team members went through in-service training that concentrated on the specific programming of the SST as well as problem-oriented policing more generally. SST officers were required to stay in their assigned areas unless an emergency call required their involvement.
There were almost 400 distinct problem-oriented policing strategies that were implemented by SST officers in the crime hot spots. The strategies fell into three broad categories:
- Situational/environment interventions that were designed to change the underlying characteristics and dynamics of the places that were believed to be linked to violence. Examples of these activities include removing graffiti and trash, adding or fixing lighting, removing abandoned vehicles, installing a CCTV system, evicting problem tenants, repairing sidewalks, and giving out crime prevention literature.
- Enforcement interventions that were meant to arrest and deter individuals that were identified as committing violent crime or contributing to a disorderly atmosphere at the targeted areas. Examples of these kinds of activities include focused enforcement efforts on drug-selling crews, street gangs, robbery crews, public housing trespassers and unregulated vendors, and burglars/shoplifters, as well as focused efforts on indicators of social disorder (public drinking, loitering, etc.).
- Community outreach/social service interventions that were supposed to stimulate community involvement in crime prevention and address problematic behaviors by disorderly individuals at the places (such as local youth with no recreational opportunities). Examples of these activities include providing new recreational opportunities for youth (i.e., basketball leagues), partnering with local agencies to provide needed social services to youth, working with clinicians to provide street outreach to the homeless, and planning community events (i.e., block parties).
Overall, Braga, Hureau, and Papchristos (2011) found mixed results when evaluating the crime control benefits of Safe Street Teams (SST). The results showed that the SST intervention was associated with significant reductions in total violent index crimes, robberies, and aggravated assaults over the 10-year study period; however, there were no significant reductions in homicides and rape/sexual assaults.
Total Violent Index Crime
The SST intervention was associated with a statistically significant 17.3 percent reduction in the number of total violent index crime incidents (which include homicide, rape/sexual assault, robbery, and aggravated assault) at the treatment street units relative to the comparison street units.
The SST intervention was not associated with a statistically significant reduction in the number of homicide incidents at the treatment street units relative to the comparison street units.
The SST intervention also was not associated with a statistically significant reduction in the number of rape/sexual assault incidents at the treatment street units relative to the comparison street units.
Relative to the comparison street units, the SST intervention was associated with a statistically significant 19.2 percent reduction in the number of robbery incidents at the treatment street units.
Finally, the SST intervention was associated with a statistically significant 15.4 percent reduction in aggravated assault incidents at the treatment street units relative to the comparison street units.
Displacement and Diffusion
The analyses revealed that all of the violent index crime categories did not experience significant displacement or diffusion effects as a result of the SST intervention. Total violent index crime, homicide, rape/sexual assault, and robbery incidents experienced nonstatistically significant decreases in the treatment two-block catchment areas relative to the comparison two-block catchment areas. Aggravated assault incidents experienced nonstatistically significant increases.
Braga, Hureau, and Papchristos (2011) used a nonrandomized quasi-experimental design to evaluate the violent crime control benefits of the Safe Street Team (SST) program at treated street segments and intersections compared with untreated street segments and intersections.
Records of Boston (Massachusetts) Police Department (BPD) official reports of violent index crime incidents between Jan. 1, 2000, and Dec. 31, 2009, were collected. Boston experienced 70,446 violent index crime incidents over the 10-year study period. The units of analyses were street segments and intersections. Street segments were defined as “the two block faces on both sides of a street between two intersections” (Weisburd et al. 2004, 290). Intersections (also called street corners) were defined as locations where two or more streets crossed. Using geocoding software, a database was created with a record for each of the 18,155 street segments and 1,375 intersections in Boston. Then the 69,550 violent index crime incidents were geocoded to a specific street address or intersection (916 incidents were not geocoded because of problematic locations in the computerized data). Geocoded incidents were aggregated to specific street segments and intersections, and tallied into yearly counts over the 10-year period.
Propensity score matching routines were used to develop equivalent comparison and treatment groups from the untreated street units and SST street units. The pretreatment street unit characteristics considered in the propensity score matching analysis were 1) 2006 violent index crime counts, 2) whether the street unit was an intersection or street segment, 3) the number of street units in the surrounding 2000 U.S. Census block group that experienced three or more violent index crimes in 2006, and 4) the concentration of social disadvantage in the surrounding 2000 U.S. Census block group. Street units that were within a two-block distance of the 13 SST areas were excluded from the comparison group to allow for subsequent analyses to determine whether the SST program resulted in immediate spatial crime displacement or a diffusion of crime control benefits into surrounding areas. In addition, any street units that did not experience a single violent index crime in 2006 were also excluded. The analysis resulted in 776 treated street units in the SST areas and 2,472 untreated street units located elsewhere in Boston.
A variation of a multilevel negative binomial regression model was used to analyze the change in violent index crime trends at treatment and comparison street units over an extended 10-year observation period (2000–2009). Analysis was also conducted to examine the crime displacement and diffusion of crime control benefits of the SST program. The analysis included 564 comparison units and 478 treatment units. A two-block comparison buffer zone was constructed around these selected locations, and violent index crime trends at these street units were compared to assess the diffusion and displacement effects for crime types that were affected by the intervention at the treatment places.
There is no cost information available for this program.
Evidence-Base (Studies Reviewed)
These sources were used in the development of the program profile:Study 1Braga, Anthony A., David M. Hureau, and Andrew V. Papachristos. 2011. “An Ex Post Facto Evaluation Framework for Place-Based Police Interventions.” Evaluation Review 35(6):592–626.
These sources were used in the development of the program profile:
Braga, Anthony A., Edward F. Davis, and Michael D. White. 2012. “Boston, Massachusetts Smart Policing Initiative: Evaluating a Place-Based Intervention to Reduce Violent Crime.” Smart Policing Initiative: Site Spotlight
. Washington, D.C.: U.S. Department of Justice, Bureau of Justice Assistance.
Braga, Anthony A., and Edward F. Davis. 2012. “Evidence-Based Policing in Practice: The Case of Safe Street Teams in Boston.” Translational Criminology
Braga, Anthony A., and Cory Schnell. 2013. “Evaluating Place-Based Policing Strategies: Lessons Learned From the Smart Policing Initiative in Boston.” Police Quarterly
Weisburd, David L., Shawn D. Bushway, Cynthia Lum, and Sue–Ming Yang. 2004. “Trajectories of Crime at Places: A Longitudinal Study of Street Segments in the City of Seattle.” Criminology