Evidence Rating: Promising | One study
Date:
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
A Promising rating implies that implementing the program may result in the intended outcome(s).
This program's rating is based on evidence that includes at least one high-quality randomized controlled trial.
Program Goals
Hot spots typically are defined as small geographic areas (e.g., street blocks or groups of street blocks) that contain unusually high levels of criminal activity (Sherman and Weisburd, 1995). This hot-spots crime intervention was conducted in Sacramento, Calif., by the Sacramento Police Department. The intervention was designed to 1) better ensure that police service to the community was delivered as intended by providing clearer guidelines on how police officers should patrol and 2) minimize boredom and maximize the effectiveness of police officers through a deployment strategy in which officers would not spend a great deal of time in the same place. The overall goal of the program was to reduce crime in the city.
Program Components/Target Sites
As of 2010 the Sacramento metropolitan area had a population of more than 2.1 million, the 24th-largest in the United States and the 4th-largest in California. Per the 2010 Uniform Crime Reporting Data, the city’s violent and property crime rates were above the national average, yet both rates had declined, compared with the prior five years. At the end of 2010 the Sacramento Police Department had 707 sworn officers eligible for assignment to patrol duties (Telep, Mitchell, and Weisburd, 2014).
In this hot-spots intervention, Sacramento Police Department officers were assigned from one to six hot spots in their patrol areas and were given a random order, which shifted daily and varied by shift, to visit their assigned hot spots. The officers were instructed to visit their assigned hot spots for 12 to16 minutes per the order provided by their unit sergeant, and to treat each hot spot in their patrol areas once every two hours. A special call sign was used for the intervention, and officers were directed to initiate a call with radio code “D1HOT” when present in their assigned hot spots.
While officers were not given specific instructions on what to do in each hot spot, they did receive daily recommendations through their in-car computers to engage in proactive activities such as traffic stops, street checks, and citizen contact. The Sacramento Police Department’s crime analysis unit tracked the officers’ movements with the department’s automated vehicle locater system to validate that officers were present in hot spots when the radio code was initiated and that intervention protocols were used.
The intervention specifically targeted areas in Sacramento that suffered from high levels of citizen-generated calls for service and crime incidents: District 3 (downtown and midtown areas and the campus of California State University, Sacramento) and District 6 (the southeastern part of the city and the neighborhoods of Oak Park and Tahoe Park).
Program Theory
Sherman and Weisburd (1995) found that targeted increase in police presence leads to some crime and disorder reduction. In addition, Koper (1995) found that the ideal time spent in a hot spot was 14 to 15 minutes; after about 15 minutes, there were diminished deterrent effects, and the increased time did not create more residual deterrence. Known as the “Koper Curve,” this theory promotes an approach in which police travel between hot spots, spending about 15 minutes in each hot spot, and move from hot spot to hot spot in an unpredictable order to increase the perception of the costs of offending in those areas. This intervention was designed to test Koper’s (1995) conclusions about the most effective and efficient police patrol strategy at hot spots.
Study 1
Part 1 Crime Incidents
Treatment hot spots had a greater decline in Part 1 crime incidents, compared with control hot spots, between the 90-day intervention period in 2011 and the same 90-day period in 2010. On average, the treatment hot spots showed a decline of 1.67 Part 1 crime incidents, while control group hot spots showed an average increase of 1.24 Part 1 crime incidents. This difference was statistically significant.
Calls for Services
Telep, Mitchell, and Weisburd (2014) found no statistically significant difference in calls for services in treatment hot spots, compared with control hot spots, between the 90-day intervention period in 2011 and the same 90-day period in 2010.
Soft Crime Incidents
There was no statistically significant difference in soft crime incidents (less-serious criminal incidents related to disorder such as public drunkenness, trespassing, and vandalism) in treatment hot spots, compared with control hot spots, between the 90-day intervention period in 2011 and the same 90-day period in 2010.
Study 2
Part 1 Property Crime Incidents
Mitchell (2017) found that treatment hot spots had a greater decline in Part 1 property crime counts, compared with control hot spots, between the 90-day intervention period in 2011 and the same 90-day period in 2010. Property crime in treatment hot spots decreased by 35.3 percent, while property crimes in the control hot spots increased by 25.3 percent. This difference was statistically significant.
Part 1 Violent Crime Incidents
There was no statistically significant difference in Part 1 violent crime counts in treatment hot spots, compared with control hot spots, between the 90-day intervention period in 2011 and the same 90-day period in 2010.
Study 1
Telep, Mitchell, and Weisburd (2014) conducted a randomized controlled trial to evaluate whether having officers move randomly from hot spot to hot spot and spend about 15 minutes in each area made an impact on crime incidents and calls for service, when compared with standard police patrol. The intervention was implemented in Sacramento, Calif., from Feb. 8, 2011, to May 8, 2011. In the planning phase, the Sacramento Police Department identified all citizen-generated calls for service for District 3 (downtown and midtown areas and the campus of California State University, Sacramento) and District 6 (the southeastern part of the city and the neighborhoods of Oak Park and Tahoe Park) from January 2009 through December 2010. The department excluded the following from the sample: 1) all noncrime-related calls, 2) calls geocoded to an intersection to create hot spots that were a street block in length, and 3) calls to certain high-call addresses that did not qualify as typical hot spots such as hospitals and the county courthouse. A total of 119,480 geocoded calls from District 3 and District 6 remained in the sample, but the department looked at the top 40 hot spots based on calls for service. For Part 1 crimes, all 2010 incidents were examined and, after intersection data and ineligible addresses were removed, a total of 7,479 incidents remained in the sample. The same criteria as calls for services were used, street segments were ranked, and the top 25 hot spots for Part 1 crimes not identified from the top 40 calls for service were added. The top 20 hot spots for soft crime incidents were assessed and removed from the sample, as they did not correlate highly with the calls for service and Part 1 crime hot spots.
After initial assessment, 52 hot spots were identified for further review. Two officers physically observed these areas to confirm that the hot spots were suitable for the experiment. Inclusion criteria at this stage included that no hot spot 1) was larger than one standard linear street block, 2) extended for more than one half-block from either side of an intersection, and 3) was within one standard linear block of another hot spot. Based on officer observations and the inclusion criteria, 42 hot spots were included in the experiment. To reduce variability between the 21 treatment hot spots (that received the intervention) and 21 control hot spots (that received standard police patrol), the hot spots were paired before randomization based on similarity in levels of calls for service, crime incidents, and similar physical appearance based on the initial observations. After pairing, a computerized random-number generator assigned hot spots to either the treatment or control group. Sixteen of the treatment group hot spots were in District 3, and five were in District 6. T-tests showed no statistically significant differences between the treatment and control hot spots in calls for service or Part 1 incidents in 2008, 2009, or 2010, suggesting that there were no baseline differences between the two study conditions. In 2010 (the preintervention period), the treatment hot spots had an average of 46.5 calls for service, 6.6 Part 1 crimes, and 2.8 soft crime incidents, while the control hot spots had an average of 40.6 calls for service, 4.5 Part 1 crimes, and 2.5 soft crime incidents.
The intervention was implemented 7 days a week, between the hours of 9:00 a.m. and 1:00 a.m. As part of this 90-day experiment, officers were assigned from one to six hot spots in their patrol areas and were given a random order, which shifted daily and varied by shift, to visit their assigned hot spots. Officers were not informed about which areas were designated as treatment or control hot spots. Each week, 10 percent of officer-initiated calls in the treatment area were randomly chosen and compared with automated vehicle locater data to determine whether officers were present in their hot spots for the same amount of time that their call logs indicated. Analyses suggested that officers complied with the experimental protocols, were always physically present in the treatment hot spots, and spent 12 to 16 minutes at a time in hot spots. The dosage levels of police presence were approximately 546 visits a week, with the lowest treatment week consisting of 432 visits and the highest 698. In general, there were 7,095 visits (averaged 78.8 visits per day) to 21 treatment group hot spots during the experiment; the total number of visits at each individual hot spot ranged from 223 to 559 visits. In total, 2,875 hours were spent on calls in the treatment hot spots versus 1,014 hours in the control hot spots.
The study examined three outcomes: 1) citizen-generated emergency calls for service to 911, per Sacramento Police Department databases; 2) Part 1 crime incidents based on the Uniform Crime Report classification of serious crimes (e.g., robbery, burglary, auto theft, and aggravated assault); and 3) soft crime incidents or less-serious criminal incidents related to disorder (public drunkenness, trespassing, and vandalism). A difference-in-differences analysis was used to compare the change in the three outcomes between the 90-day intervention period in 2011 and the same 90-day period in 2010 in the treatment hot spots versus the control hot spots. No subgroup analysis was conducted.
Study 2
Mitchell (2017) examined the randomized controlled trial of hot spots in Sacramento, Calif., conducted by Telep, Mitchell, and Weisburd (2014) (Study 1) for a new analysis of crime count decoupled by crime category (violent and property). The hot spot selection, methodology for matching, and randomization process were the same as described in Study 1 (above). The intervention was implemented with the same 21 treatment hot spots (where officers visited one to six high-crime and call-for-service hot spots for 15 minutes of high-visibility patrol multiple times per day) and 21 control hot spots (that received standard police patrol) in Sacramento, Calif., for 90 days from Feb. 8, 2011, to May 8, 2011.
In Study 1 (Telep, Mitchell, and Weisburd, 2014), the study authors examined three primary dependent variables: 1) calls for service, 2) Part 1 crime incidents, and 3) soft crime incidents during the study period in 2011 and the same period in 2010. In Study 2 (Mitchell, 2017), the study author used only the Part 1 crime incident data to examine violent and property crime incidents separately. T-tests showed no statistically significant differences between the treatment and control hot spots in Part 1 incidents in 2010, suggesting there were no baseline differences between the two study conditions. In 2010 (the baseline period), the treatment hot spots had an average of 6.6 Part 1 crimes, while the control hot spots had an average of 4.5 Part 1 crimes.
Rather than analyzing the data by pairs, the data were analyzed as a pooled analysis, making the statistical test more conservative. The analysis included difference-in-difference testing for Part 1 property and violent crime count change between the baseline 90-day period in 2010 and the 90-day experimental period in 2011, comparing the treatment hot spot changes with the control hot spots. No subgroup analysis was conducted.
Additional Outcomes
Telep, Mitchell, and Weisburd (2014) also assessed several other outcomes, including 1) response time, 2) crime displacement, and 3) officer proactivity. In District 3, where most of the study’s hot spots were located, the average response time decreased, when comparing the experimental period with the same period in 2010. In District 6, the average response time increased; however, these changes were minimal and still higher than the average response time for other districts in the city. In terms of crime displacement, there were increases in calls for service and Part 1 crime incidents in the two-block treatment group catchment area, and decreases for both outcomes in the control group catchment area, but these changes were not statistically significant. When examining officer proactivity, excluding calls directly related to experimental protocols, both Districts 3 and 6 showed increases in officer-initiated activity, which suggests that officers did not remain in their patrol cars but were engaged in a great deal of proactivity in the treatment areas.
These sources were used in the development of the program profile:
Study 1
Telep, Cody W., Renée J. Mitchell, and David Weisburd. 2014. “How Much Time Should the Police Spend at Crime Hot Spots? Answers from a Police Agency Directed Randomized Field Trial in Sacramento, California.” Justice Quarterly 31(5):905–33.
Study 2
Mitchell, Renée J. 2017. “The Usefulness of a Crime Harm Index: Analyzing the Sacramento Hot Spot Experiment Using the California Crime Harm Index (CA–CHI).” Journal of Experimental Criminology 15:103–13.
These sources were used in the development of the program profile:
Koper, Christopher S. 1995. "Just Enough Police Presence: Reducing Crime and Disorderly Behavior by Optimizing Patrol Time in Crime Hot Spots." Justice Quarterly 12(4):649–72.
Mitchell, Renée J. 2017. “Frequency Versus Duration of Police Patrol Visits for Reducing Crime in Hot Spots: Non-Experimental Findings from the Sacramento Hot Spots Experiment.” Cambridge Journal of Evidence-Based Policing 1:22–37.
Sherman, Lawrence W., and David L. Weisburd. 1995. “General Deterrent Effects of Police Patrol in Crime ‘Hot Spots’: A Randomized, Controlled Trial.” Justice Quarterly 12(4):625–48.
Weisburd, David, and Cody W. Telep. 2014.” Hot Spots Policing: What We Know and What We Need to Know.” Journal of Contemporary Criminal Justice 30(2):200–220.
Following are CrimeSolutions-rated programs that are related to this practice:
Hot spots policing strategies focus on small geographic areas or places, usually in urban settings, where crime is concentrated. Through hot spots policing strategies, law enforcement agencies can focus limited resources in areas where crime is most likely to occur. This practice is rated Effective for reducing overall crime and rated Promising for reducing violent, property, public order, and drug and alcohol offenses.
Evidence Ratings for Outcomes
Crime & Delinquency - Multiple crime/offense types | |
Crime & Delinquency - Violent offenses | |
Crime & Delinquency - Property offenses | |
Crime & Delinquency - Public order offenses | |
Crime & Delinquency - Drug and alcohol offenses |
In 2017, Crime Hot Spots Intervention (Sacramento, Calif.) received a final program rating of No Effects, based on the review of the study by Telep, Mitchell, and Weisburd (2014). In May 2022, CrimeSolutions conducted a re-review of Telep, Mitchell, and Weisburd (2014) and an additional study by Mitchell (2017), using the updated CrimeSolutions Program Scoring Instrument. The program received a new final rating of Promising.
Geography: Urban
Setting (Delivery): High Crime Neighborhoods/Hot Spots
Program Type: Community and Problem Oriented Policing, Hot Spots Policing, Violence Prevention
Current Program Status: Not Active
University Center, 411 N Central Avenue, #600
Cody Telep
Associate Professor
School of Criminology and Criminal Justice, Arizona State University
Phoenix, AZ 85004
United States
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