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 |
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 |
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 |
Los Angeles, CA2009 | The Los Angeles SPI addressed gun-related violence using Operation LASER (Los Angeles’ Strategic Extraction and Restoration Program).
| Research Design Interrupted time-series analysis, which assesses whether the interventions in target areas had an effect on crime while controlling for previous trends. (Research evaluation is ongoing.) Findings22.6% reduction in homicides per month in the target division. 5.2% reduction in gun crimes per month in each reporting district of the target division. | Gun Violence, Violence Reduction |
New Haven, CT2011 | The New Haven SPI addressed rising violent crime and local shooting incidents in a persistently violent neighborhood in the city.
| Research Design Pre-intervention, intervention, and post-intervention analysis in target and control areas. FindingsDuring intervention, 19% reduction in violent crime at the neighborhood-level and 36% reduction in violent crime in high-risk areas. 13 weeks following the intervention, 41% violent crime reduction at the neighborhood level and 56% reduction in the high-risk areas. | Gun Violence, Violence Reduction |
Philadelphia, PA2009 | The Philadelphia SPI tested the impacts of three police strategies in violent crime hotspots (foot patrols, POP, offender-focused policing).
| Research Design Process and outcome evaluation of the randomized control design FindingsOffender-focused strategy outperformed foot patrol and problem-solving strategies. Compared to the control areas, the treatment areas that received the offender-focused strategy experienced a 22% decrease in violent crime, and a 31% decrease in violent street felonies. | Violence Reduction |
Phoenix, AZ2011 | The Phoenix SPI aimed to improve relations with minority communities by developing a body-worn camera (BWC) program.
| Research Design Process and outcome evaluation, pre- and post- deployment FindingsFrom pre- to post-deployment, officers with BWCs experienced a 22.5 percent decline in officially recorded complaints, while across all other precincts there was a 45.1 percent increase in complaints. | Technology |