SPI Findings
SPI Findings
Site | Implementation | Research Design & Findings | Topic |
---|---|---|---|
Boston, MA2009 | The Boston SPI addressed violent crime, especially robberies and assaults committed with guns, using community policing and problem-oriented policing Safe Streets Teams (SSTs).
| Research Design A quasi-experimental design with propensity score matching (statistically based matching of target sites to control/comparison sites). FindingsMore than 17% reduction in violent crime. More than 15% reduction in aggravated assaults. More than 19% reduction in robberies. | Gun Violence, Violence Reduction |
Boston, MA2011 | The Boston SPI implemented the Boston Homicide Clearance Intervention to improve homicide clearance rates and investigations.
| Research Design Process evaluation of homicide protocols, impact evaluation during the implementation period, overall outcome evaluation of clearance rates. Findings9.8% increase in homicide clearance rates. 18.4% increase in adjusted homicide clearance rates (including cases awaiting a grand jury). | Violence Reduction |
Brooklyn Park, MN2013 | The Brooklyn Park, MN SPI - the Assets Coming Together to Take Action (ACT) Initiative —aimed to reduce crime at hot spots by garnering greater cooperation and collaboration with the public in addressing crime problems. The intervention was also designed to increase collective efficacy among citizens residing in the hot spots, and improve their evaluations of police legitimacy. A key innovation of ACT was the involvement of the entire patrol force in delivering the program: all patrol officers were expected to undertake the activities described below during their discretionary time when they were not responding to 911 calls, taking breaks, or report writing. | Research Design The research partner evaluated ACT using a partially block-randomized controlled trial in which 42 identified hot spots were matched into groups according to their crime rates and overall land use of the site (e.g., commercial, residential). The hot spots were then randomly allocated into treatment (ACT) or control (policing as usual) conditions within their matched groups. Findings
| Community Engagement, Violence Reduction |
Cambridge, MA2011 | The Cambridge SPI, a collaborative effort with the cities of Everett and Somerville, called RASOR (Regional Analytics for the Safety of Our Residents), focused on preventing victimization and social harm.
| Research Design Outcome evaluation and process evaluation of the randomized experimental design. FindingsNo statistically significant differences in time to arraignment between RASOR and control. The more time invested by case management and services, the longer the survival time of individuals participating in RASOR (i.e., did not reoffend as quickly as the control group). | Violence Reduction |
Chicago, IL2015 | The Chicago, IL SPI addressed violent crime through implementation and evaluation of the police department’s Strategic Decision Support Centers (SDSC). Chicago’s SDSCs bring together police officers and analysts from the University of Chicago Crime Lab to integrate crime intelligence, data analysis, and technology in daily, real-time approaches to violent crime reduction and prevention. The Chicago SPI expanded SDSCs into six districts in the city, and evaluated the impact of this expansion on violent crime in the target districts and citywide. | Research Design The SPI conducted a process evaluation of SDSCs for developmental and operational lessons learned. The site also employed a difference-in-difference models to estimate crime reduction effects resulting from adding an SDSC to a Chicago police district. Findings
| Gun Violence, Violence Reduction |
Chula Vista, CA2013 | The Chula Vista, CA SPI developed the Domestic Abuse Response Team (DART) and provided assigned officers a protocol to follow at each Domestic Violence (DV) call involving Intimate Partners (IP).The DV protocol developed was carried out by patrol officers in one sector of the city along with their regular call-handling responsibilities.
| Research Design The study used a quasi-experimental design to evaluate the impact on crimes, calls, and repeats, assessing whether dyads or locations
| Violence Reduction |
Glendale, AZ2009 | The Glendale SPI sought to reduce crime and disorder pertaining to convenience store thefts in the southeast quadrant of the city.
| Research Design Pre/post analysis with multiple units and multiple control groups, interrupted time series analysis of convenience stores. FindingsDecline in calls for service in 5 of 6 target stores. 18% reduction in direct costs for officer response and estimated decrease of more than $1.9 million in victimization costs. Sustained reduction in 4 of 6 target stores (nearly 20% in calls for service overall, two years after the intervention). | Violence Reduction |
Glendale, AZ2011 | The Glendale SPI continued the efforts of its prior project by focusing POP efforts on problem offenders and organizational retail theft.
| Research Design Bivariate analysis and interrupted time series analysis. FindingsIdentified and targeted prolific offenders, and generated short-term, notable declines in several micro hot spots. 27% reduction in calls for service in a target area (large mall) and short-term 15% reduction in calls for service in a target apartment complex. | Violence Reduction |
Kansas City, MO2012 | The Kansas City SPI addressed violent crime, particularly gun violence, using a model called the Kansas City No Violence Alliance (KC NoVA).
| Research Design Bivariate analysis and interrupted time series analysis to assess the impact of the focused deterrence pulling levers strategy. Findings40% reduction in homicide. 19% reduction in gun-related aggravated assaults. | Gun Violence, Violence Reduction |
Kansas City, KS2016 | The Kansas City, MO SPI approach employed evidence-based strategies incorporating both place-based and person-based violence prevention methods in a micro hot spot (MHS) network experiment. The SPI implemented two interventions to examine the effectiveness of each in the East Patrol Division:
| Research Design The sites, with buffer zones, were randomly assigned as either treatment or control areas: five for saturation patrol; five for network-based intervention (NBI); and six control areas. Comparable pre- and post-intervention periods were established to measure results and changes over time. Findings
| Violence Reduction |