Law Enforcement Operations

The program focuses on reducing violent gun crime by disrupting the cycle of gun violence by relying on forensic science and data analysis to identify, investigate, and prosecute individuals who use guns in criminal activity, and the sources of their guns. The program is rated No Effects. The program did not significantly affect homicides or aggravated assaults with a firearm but was shown to significantly reduce violent crime and robbery with a firearm.

This involves police officers wearing cameras on their uniforms to improve the civility of their interactions with citizens. The program is rated Effective. There were statistically significant reductions in citizen complaints against police and police use-of-force reports for officers who wore cameras, compared with those who did not, and statistically significant reductions in complaints against control officers in the treatment districts, compared with officers in the untreated districts.

This program involves 15 minutes of police patrol in high-crime hot spots to reduce crime. The program is rated Promising. There were statistically significant reductions in reports of violent crimes and robbery and other crimes against personal victims in hot spots on treatment days, compared with control days.

This program equips police with on-officer cameras to record their interactions with civilians. The program is rated No Effects. Camera use had no statistically significant effects on officers’ total number of proactive activities, specifically on the number of traffic stops or business checks, nor on arrests, citizen complaints, and use-of-force incidents. Officers with cameras conducted statistically significantly fewer subject stops, and statistically significantly more park and walks.

This program involves police use of video to improve evidence gathering and police and citizen behavior. The program is rated No Effects. There were no statistically significant differences in restraining orders issued or assaults on police between body-worn video treatment days and control days (when no officers wore body-worn video). Treatment days had statistically significantly higher rates of use of force, citizen complaints against police, and criminal charges, compared with control days.

This policing strategy was designed to deter crime on platforms in high-crime areas of the London Underground. The program is rated Promising. Platforms in the treatment areas had statistically significant reductions in calls for services and crime, relative to the control group, on patrol and nonpatrol days.

This program involved the use of a crime forecasting model to direct police patrol to dynamic hot spots to reduce crime. The program is rated Promising. There were statistically significant reductions in daily crime volume (specifically burglary, car theft, and burglary-theft from vehicle) for police patrols in the treatment condition, compared with patrols in the control condition.

This program involves law enforcement’s use of cameras to record interactions with civilians to reduce citizen fatalities. The program is rated Promising. Agencies that acquired cameras had statistically significant decreases in fatal police–citizen encounters after three years, compared with agencies that did not acquire cameras. There were no statistically significant differences in fatal encounters between a reduced set of agencies with cameras and matched agencies without cameras.

This program equips police with body cameras to record encounters with civilians. The program is rated No Effects. Camera use had no statistically significant effects on number of arrests, arrests with force, and summonses issued after 1 year. Officers wearing cameras had statistically significant reductions in complaints filed against them and made more stop reports. Camera use resulted in a statistically significantly reduced likelihood of lawful stops and frisks but fewer subjects searched.

This program was designed to reduce excessive drinking among adolescents and young adults ages 12-25 through community-wide enforcement operations and awareness campaigns. The program is rated Promising. There was a statistically significant reduction in alcohol-related motor vehicle crashes among 15- to 30-year-old drivers in treatment group cities, compared with control group cities.

This is a place-based intervention that uses environmental design at high-crime businesses in the city to reduce crime and improve public safety. The program is rated No Effects. There were no statistically significant effects on disorder occurrences or violent crime. The intervention did result in statistically significant reductions in property crime around treated businesses, compared with matched control businesses, at 1-year postimplementation.

The program involved the use of hot-spots policing tactics in certain neighborhoods of Montevideo to reduce incidents of robbery. The program is rated Promising. Compared with the control group hot-spot areas, treatment group hot-spot areas that received increased police presence (in the form of foot patrol) experienced a statistically significant reduction in robbery.

This is a procedural justice checklist for counterterrorism police officers working in ports of travel in a European country to use when questioning people suspected of terrorism. The program is rated Effective. People interviewed by officers using the checklist reported a statistically significantly greater view of distributive justice, effectiveness of police, obligation to obey the law, and willingness to cooperate with the police, compared with people interviewed by control group officers.

This strategy sought to reduce crime in Philadelphia by testing three different patrol strategies. The program is rated No Effects. Relative to control areas, there was no statistically significant difference in violent or property crimes in areas using one of two of the patrol strategies. Property crimes in an area using one of the strategies saw a statistically significant decrease, while there was a statistically significant increase in violent crime in areas using two of the strategies.

This program equips police with on-officer cameras to record contacts with civilians. The program is rated Promising. Body-worn camera use resulted in statistically significant decreases in citizen complaints, and there were mixed results regarding camera use on arrest rates. There were no statistically significant differences in citizen resistance. There was a statistically significant increase in use of force, and less proactive, officer-initiated contact.

This program equips police with on-officer cameras to record contacts with civilians during intimate-partner violence incidents. The program is rated Promising. Camera use was statistically significantly more likely to result in arrests, charges filed, cases furthered, and both guilty pleas and verdicts. There was no statistically significant difference in sentence length. However, there was a statistically significantly greater reduction in case processing time in cases not involving a camera.

This is a police-operated public surveillance program that seeks to reduce crime and increase crime clearances (i.e., arrests) by installing new closed-circuit television cameras at high-crime, high-traffic intersections in Milwaukee (Wis.). The program is rated Promising. Intersections in intervention areas where new cameras were installed had a statistically significant higher rate of crime clearances for all crime types, compared with intersections in comparison areas.

This was an experiment designed to evaluate the effectiveness of hot spots policing in urban and suburban areas. The program is rated No Effects. There were no statistically significant differences between treatment and control hot spots in part 1 crimes, part 2 crimes, and crime-related calls for service. However, results showed a statistically significant reduction in crime-related calls for service in urban locations relative to suburban locations.

Police body-worn cameras (BWCs) are designed to improve policing and the perceived legitimacy of the police and legal institutions. The program is rated No Effects. There were no statistically significant differences in police use of force, number of citizen complaints, or number of arrests for disorderly conduct for police officers who wore BWCs, compared with officers who did not wear BWCs.

The program is designed to reduce officer use-of-force incidents and citizen complaints by providing body-worn cameras to officers in the Las Vegas (Nevada) Metropolitan Police Department. The program is rated Promising. There was a statistically significant reduction in police use-of-force and citizen complaints, and a statistically significant increase in arrests and citations for officers who wore the BWCs, compared with non-BWC control group.

This program relies on hot spots policing strategies to prevent thefts from vehicles and residential burglaries in “micro-time” hot spots in Port St. Lucie, Florida. The program is rated Effective. There was a statistically significant reduction in thefts from vehicles and residential burglaries in micro-time hot spots that received tactical police responses, compared with micro-time hot spots that received police patrol as usual.

This is a focused policing strategy to reduce calls for service and crime in hot spots using increased foot patrols by civilian police community support officers. The program is rated No Effects. Hot spots that were assigned civilian proactive police community support officers did not experience statistically significant reductions in calls for service or crime.

This intervention used two hot spots policing strategies (problem solving and directed patrol) to improve citizens’ perceptions of police in St. Louis, Mo. The program is rated No Effects. Although residents in both treatment groups reported a statistically significant increase in cooperation with the police, the preponderance of evidence suggests that the intervention had no significant impact on citizens’ perceptions of procedural justice, police legitimacy, or police abuse.

Police body-worn cameras are used to record police encounters with citizens during officers’ shifts in Birmingham South. Officers were instructed to begin recording as soon as they left their vehicles and to conclude recording once the situation was resolved. The program is rated Promising. There was a statistically significant reduction in officers’ use of force and citizen injury, but no statistically significant reduction in officer injury.

This is a police body-worm camera intervention that has been implemented across eight police departments in the United States and United Kingdom. The program equips officers with continuously recording body-worn cameras to record police and citizen interactions. The program is rated No Effects. There was no significant effect on police use of force, and use of cameras was associated with a statistically significant increase in assaults against officers.

This program is designed to deter street-level crime in Newark using closed-circuit cameras, hard-wired to physical structures, which are monitored in real time by CCTV operators. The program is rated No Effects. Results from one study showed no statistically significant differences in shootings, auto thefts, or thefts from autos. Results from a second study showed a statistically significant decrease in auto thefts but no statically significant difference in shootings or thefts from auto.

This program aims to improve police officers’ forensic evidence-collection techniques at burglary crime scenes to increase solved burglaries. The program also intends to improve police–victim and police–witness interactions at burglary crime scenes. The program is rated Promising. Results showed a statistically significant increase in solved burglary cases.

This is a criminal investigation method used by law enforcement to increase burglary arrest rates using statistically derived profiles of convicted persons. The intervention was implemented in one police department in Florida for use in active burglary investigations. The program was rated Effective. Results showed a statistically significant increase in burglary arrest rates for the police department that implemented the program.

This program involved officers patrolling crime hot spots in roughly 15-minute intervals to reduce crime. The program is rated Promising. There were statistically significant reductions in aggregated Part 1 crimes and Part 1 property crimes in the treatment hot spots, compared with control areas, during the 90-day intervention period, when compared with the same period 1 year prior. However, there was no statistically significant effect on calls for service, soft crime, and Part 1 violent crimes

This program examined whether access to deployment data collected through technology impacted police commanders’ management of resources and led to reductions in crime. The program is rated No Effects. There was a statistically significant decrease in crime at the hot spot level. However, there were no significant differences in crime at the beat level, in consistency between patrols assigned and delivered per beat and per hot spot, or in number of hours of patrol on beats or in hot spots.

This program equips individual police officers in Rialto, Calif., with body-worn cameras to record police encounters during shifts. The program aims to reduce use-of-force incidents and citizen complaints by increasing mutual accountability. The program is rated Promising. There was a statistically significant reduction in police use-of-force, but no statistically significant difference in citizens’ complaints.

The program involved incorporating elements of procedural justice into traffic stops in Adana, Turkey, to test whether procedural justice improves citizens’ perceptions of the police and the law. The program is rated No Effects. No statistically significant differences were found between the treatment and control groups on general perceptions of the police, but the study did find statistically significant differences between the treatment and control groups in encounter-specific perceptions.

This experiment assessed the impact of two hot spots policing tactics on firearm violence. The program is rated Promising. Compared with comparison hot spots, hot spots that received self-initiated enforcement experienced a statistically significant reduction in firearm assault rates, but there were no statistically significant differences for hot spots that received directed patrol. There was no statistically significant effect on firearm robbery rates between treatment and comparison hot spots

This is a law-enforcement model in which both location-based crime and automobile crash data is analyzed to determine where such incidents disproportionately occur (“hot spots”) and to employ targeted traffic enforcement strategies. The program is rated Promising. The areas of targeted enforcement experienced statistically significant declines in robberies, burglaries, and traffic crashes.

This strategy is aimed at reducing crime at violent-crime hot spots in Philadelphia, Pa., through police foot patrols. It involved having veteran officers patrol areas (an average of 3 miles of streets) during one shift per day. This program is rated No Effects. Relative to the control areas, increasing foot patrols at violent-crime hot spots had no statistically significant impact on violent crimes, violent felonies, or citizens’ perceptions of crime and safety.

The program tested whether police use of a specialized script (based on principles of procedural justice) during random breath-test traffic stops could improve perceptions of police and change people’s views about drinking and driving. The program is rated Promising. The program was shown to have a statistically significant effect on changing views on police and on drinking and driving, on increasing satisfaction and compliance with police, and on strengthening perceptions of procedural justice.

This is a seat-belt-enforcement campaign initiated and funded by the National Highway Traffic Safety Administration. The overall goal is to improve road safety by requiring drivers and passengers in vehicles to properly wear their seat belts. The program is rated Promising. There was a statistically significant decrease in motor vehicle accidents, but no impact on non-fatal injuries caused by vehicle accidents.

A crime prevention strategy designed to reduce crime in Washington Metropolitan Area Transit Authority parking facilities through the introduction of digital cameras at the exits of the parking facilities to capture images of patrons’ license plates as they exited the facility. The program is rated as No Effects. Crime rates (including car-related, property, and violent crimes) remained at pre-camera levels in parking facilities.

This program aims to improve homicide clearance rates by increasing investigative time through the transfer of four crime scene specialists to the homicide unit. The program is rated No Effects. There were no statistically significant differences between treatment and comparison squads in case and victim clearance by arrest. There were also no statistically significant difference between squads in case and victim clearance by quick action and whodunit arrests, or quality of scene reports.

This is a public surveillance system that includes a network of cameras and components for monitoring, recording, and transmitting video images to monitor crime in different areas of Baltimore, Md. The program is rated Promising. There was a statistically significant decrease in total monthly crime in the downtown, Greenmount, and tri-district areas of Baltimore between pretest and posttest. However, there was no statistically significant difference in the North Avenue area.

This program consists of the use of a vehicle-scanning device deployed by law enforcement to detect vehicles that have been reported stolen or missing. The program is rated No Effects. There were no statistically significant program effects on general crime, auto-related crime, vehicle-theft calls for service, or auto-theft.

This was a saturation foot-patrol initiative implemented in Newark, N.J., in 2008 that aimed to reduce violent crime. The program is rated Promising. The target area that implemented the initiative experienced statistically significant reductions in overall violence and incidences of aggravated assault and shootings, compared with the control area. However, there was no statistically significant effect on incidences of murder or robbery.

This is a comprehensive antiviolence initiative that uses collaborative strategies to alter perceived costs and benefits of gun violence and is intended to reduce illegal gun offending. The program is rated Promising. Treatment areas experienced a statistically significant reduction in homicide and gun-related homicides, but no reduction in gang-related homicides. In addition, offender notification forums were associated with statistically significant reductions in recidivism rates.

This program consisted of a police patrol experiment, which was designed to reduce gun violence in Kansas City (Mo.) by placing extra police patrols in gun crime hot spots. The program is rated Promising. In the treatment area, there was a statistically significant increase in gun seizures and a statistically significant decrease in gun crimes, compared with the comparison area, in the 6 months following implementation.

This is a geographically focused policing strategy to reduce violent crime in high-crime areas using problem-oriented policing (POP) and saturation/directed patrols. The program is rated No Effects. While there were no statistically significant reductions in any violent or property crime in POP hot spots, or in any violence or property crime in directed patrol hot spots, there were statistically significant reductions in nondomestic violent crime in POP hot spots compared with control hot spots.

This program consists of installing closed circuit television (CCTV) cameras, to deter crime in five cities in England. The program is rated Promising. Intervention sites that installed CCTV cameras experienced a statistically significant reduction in assault-related emergency department visits, compared with control sites that did not install CCTV cameras. However, there was no statistically significant difference between intervention and control sites in police-reported violent offenses.

This is an automated ballistics imaging and analysis system that populates a computerized database of digital ballistic images of bullets and casings from crime guns, to assist forensic experts in making identifications for police investigations and trials. The program is rated Effective. There was a statistically significant 6.23-fold increase in the monthly number of cold hits generated by the Ballistics Unit after implementation of the automated ballistics imaging and analysis program.

This is a program that increased police presence in crime “hot spots” to reduce criminal activity in Minneapolis, Minn. The program is rated Effective. Experimental hot spots experienced statistically significant reductions in citizen calls to police and observed disorder, compared with control hot spots.

This was an experiment to evaluate the impact of deoxyribonucleic acid (DNA) evidence collection and testing on the investigation of high-volume property crimes. The program is rated Effective. Across five sites, more suspects were identified, arrested, and prosecuted in the treatment group cases, compared with suspects in the control group cases. These differences were statistically significant.

This program consists of a specialized police unit, which was designed to prevent recidivism among people convicted of domestic violence offenses and to assist victims of domestic violence through the process of prosecution and recovery. The program is rated Promising. The treatment group assigned to the Domestic Violence Unit had a statistically significant lower likelihood of recidivating, compared with the control group, who were assigned to standard patrol.

This was a special police unit that conducted raids of crack houses to reduce crack-related crime and improve public order in Kansas City, Mo. The program is rated No Effects. There were no statistically significant differences between the experimental and control groups in calls for service (including calls for violent, property, and disorder offenses) and reported offenses (including violent and property offenses).

The town of Redton, England, installed closed-circuit television cameras in the central commercial district to reduce crime. The program is rated Promising. Using a trend analysis, there was no significant overall crime decrease. However, in analyses of separate types of crime, controlling for trends, the reduction was significant for some types of crime (theft of and from vehicles), but not from others (other theft, shoplifting).

This program consists of using closed-circuit television cameras in the town center and adjacent car parks, or parking lots, in Gillingham, England. The program is rated Promising. The treatment area where the cameras were installed experienced a statistically significant reduction in overall crime, compared with the comparison area.

This is a multi-agency team-based, drug-control program in Oakland, Calif., which is designed to reduce drug-related problems and improve habitation conditions at targeted problem areas. The program is rated Effective. Treatment areas experienced a statistically significant decrease in police contacts following the implementation of the program.

This is a program designed to reduce drug dealing at residential rental properties by encouraging improved property management practices. The program is rated Effective. The treatment group that implemented the full program experienced a statistically significant reduction in crime, compared with the control group However, there was no statistically significant difference between the treatment and control groups in the eviction of persons convicted of drug offenses.

This program installed closed-circuit television cameras to monitor public space in different locations around the city of Philadelphia, PA. This program is rated Promising. The intervention showed a statistically significant reduction in disorder crime and the number of crime events in the target areas, compared with the control areas. However, no significant differences were found for serious crimes in the target areas, compared with the control areas.

This is a statewide sobriety deterrence program that seeks to combat impaired driving and reduce alcohol-related car crashes and fatalities in the state of Tennessee. The program is rated Promising. The program was found to have a statistically significant reduction on the number of drunk driving fatal crashes and nighttime single-vehicle injury crashes, compared with preintervention trends.

This is a community-based approach to reducing and preventing crime while revitalizing the community. This program is rated No Effects. There were no statistically significant differences in rates of violent crime between the treatment and comparison areas following the crackdown. However, drug offenses increased significantly in the treatment areas, compared with the comparison areas.

This was a policing initiative that targeted specific gangs in the Hollenbeck area of Los Angeles, California, through aggressive enforcement and problem-oriented policing. The program is rated Promising. There was a statistically significant reduction in overall violent crimes in targeted blocks, compared with matched comparison blocks. However, there was no statistically significant effect on gang crimes or gun crimes.

This is a policing program designed to reduce crime through the management of police resources in Fort Worth, Texas. The program is rated Promising. Following the implementation of Compstat in Fort Worth, there was a statistically significant reduction in rates of overall crime and property crime, and a statistically significant increase in arrests for minor nuisance offenses. However, there were no statistically significant effects on violent crime rates.