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Program Profile: Minneapolis (MN) Hot Spots Experiment

Evidence Rating: Effective - One study Effective - One study

Date: This profile was posted on June 14, 2011

Program Summary

A program that increased police presence in crime “hot spots” to reduce criminal activity in Minneapolis, Minnesota. The program is rated Effective. In hot spots that did not receive intensified police patrols, there was a greater increase in citizen calls to police than in the experimental locations. There also was less observed disorder at the experimental sites.

Program Description

Program Goals/Target Population
Minneapolis Hot Spots Experiment was a targeted policing program with the goal of preventing and reducing overall crime in high-crime areas in Minneapolis, Minnesota. In order to deter criminal activity, the Minneapolis Police Department utilized strategies to identify "hot spots" of crime and increase police presence in these areas. The strategies implemented by the program were intended to provide a general deterrent effect in high-crime areas.

Program Activities
The program focused on small clusters of high-crime addresses, rather than entire patrol beats or neighborhoods. These were known as “hot spots” of crime, and were identified based on the frequency of calls for service to the area. Officers from the Minneapolis Police Department provided intensive patrol services to the high-crime areas of Minneapolis. The program focused on increasing police presence in “hot spots” of crime, rather than the specific activities conducted by officers during patrols. The implementation of the strategy depended on the cooperation of the entire police force; this was facilitated using briefings, pizza parties, and the distribution of t-shirts with the program’s logo.

Program Theory
The Hot Spots Experiment was based on the idea that increased police presence can effectively reduce criminal activity. This theory was applied by focusing law enforcement efforts in high-crime areas identified as “hot spots” of crime. The idea was that since the highest amounts of crime were concentrated in selected geographic regions, increasing police presence specifically in these areas would produce substantial reductions in crime. The program used a proactive policing strategy to prevent crimes from occurring, as opposed to a reactive strategy that makes arrests after a crime has already been committed. Overall, this strategy was based on the general theory of deterrence; that the mere presence of law enforcement in an area will deter offenders from committing crime.

Evaluation Outcomes

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Study 1

Citizen Calls to Police

When Sherman and Weisburd (1995) compared calls from citizens in the year preceding the experiment to calls made during the 12 months of the experiment, a dramatic difference was observed. Regardless of which cutoff date was selected, the increase in citizen calls to police in the 55 control hot spots was considerably greater than in the 55 experimental hot spots. The majority of the calls to police were soft crime calls, and over the span of the entire year the increase in soft crime calls was 75 percent greater for the control group than for the experimental group. The overall effects of total crime calls were similar, since soft crime calls accounted for most of the total calls.

 

Observed Disorder

There were significant differences between experimental and control groups for the observed disorder outcome. For the entire treatment period, there was a significant relative difference of 25 percent less disorder for the experimental group than for the control group. For the two periods with the highest integrity (ending June 15 and July 31), the control group had twice as much observed disorder as the experimental group had. The results were found to be statistically significant, regardless of time period studied.

 

Overall, the effects of the experiment on preventing crime were found to be modest, but consistent. From these results, Sherman and Weisburd concluded that increases in police presence have a moderate deterrent effect on crime, and that the difference in crime is proportionate to the amount of police presence.

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Evaluation Methodology

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Study 1

Sherman and Weisburd (1995) conducted a randomized field trial to evaluate the impact on crime of increased police presence in specified "hot spots" in Minneapolis. First, they identified the hot spots of crime by analyzing calls made to police by citizens from June 6, 1987, to June 5, 1988, and compiled clusters of addresses that produced the highest volume of calls. After careful analysis, 110 sites were identified. The sites were then randomly assigned to either the control group or the experimental group, each consisting of 55 sites.

 

The experiment lasted 1 year, from Dec. 1, 1988, to Nov. 30, 1989. During this period, police patrol was intensified in the treatment hot spots (though presence was intermittent rather than constant). For 7 days a week, police officers patrolled the hot spots for 3 hours at a time during 2 dosage periods: 11 a.m. to 7 p.m., and 7 p.m. to 3 a.m. These were the times identified as “hottest,” as determined by the number of calls made to police, thus the experiment was limited to the period between 11 a.m. and 3 a.m.

 

To evaluate the impact of the police presence on crime, the researchers first analyzed phone calls made to police by citizens (as distinguished from calls made from police to dispatchers). Using information obtained from police logs, the researchers compared phone calls in the year preceding the experiment (Dec. 1, 1987, to Nov. 30, 1988) to calls made during the 12 months of the experiment (Dec. 1, 1988, to Nov. 30, 1989). Sherman and Weisburd distinguished between calls from the public regarding “hard crime” and “soft crime,” with calls about “hard crime” including more serious crimes.

 

They also employed 16 observers and 3 supervisors to monitor crime and disorder in the 50 most-active hot spots in both the experimental and the control group, coming to a total of 100 observed sites. All observations were made between 7 p.m. and 3 a.m. The two outcomes measured in the study were number of citizen calls made to police and observed disorder.

 

To ensure compatibility with the research protocol, unit-minute ratios were computed; these are a measure of the number of minutes police spent in a location to all observed minutes of the group. The mean unit-minutes across hot spots within experimental groups were generally consistent, but the combined ratio between treatment groups and control groups varied greatly over calendar months. Data from May to August varied to a great extent because of peaks in call loads for these months and vacation time for officers. Because of these factors, the differences in outcomes between experimental and control groups for these months were substantial enough to disrupt the experiment. This left only 6½ months of data of the fully implemented experiment. In addition, a new computer-aided dispatch system was implemented from Oct. 1 through Nov. 10, 1989, which caused errors in reporting data. Thus, the researchers proposed four time periods for proper analysis of the data: 1) Dec. 1, 1988, through June 15, 1989; 2) Dec. 1, 1988, through July 31, 1989; 3) Dec. 1, 1988, through Nov. 30, 1989; and 4) Dec. 1, 1988 through Nov. 30, 1989, excluding Oct. 1 through Nov. 10. They conducted analyses for all 4 periods but decided the period with the July 31 cutoff date was most suitable to test the hypothesis.

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Cost

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There is no cost information available for this program.
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Evidence-Base (Studies Reviewed)

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These sources were used in the development of the program profile:

Study 1

Sherman, Lawrence W., and David A. Weisburd. 1995. “General Deterrent Effects of Police Patrol in Crime ‘Hot Spots’: A Randomized, Controlled Trial.” Justice Quarterly 12(4):625–48.


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Additional References

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These sources were used in the development of the program profile:

Koper, Christopher. 1995. “Just Enough Police Presence: Reducing Crime and Disorderly Behavior by Optimizing Patrol Time in Police Hot Spots.” Justice Quarterly 12(4):649–72.


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Related Practices

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Following are CrimeSolutions.gov-rated practices that are related to this program:

Hot Spots Policing
Used by many U.S. police departments, hot spots policing strategies focus on small geographic areas or places, usually in urban settings, where crime is concentrated. The practice is rated Effective. The analysis suggests that hot spots policing efforts that rely on problem-oriented policing strategies generate larger crime reduction effects than those that apply traditional policing strategies in crime hot spots.

Evidence Ratings for Outcomes:
Effective - One Meta-Analysis Crime & Delinquency - Multiple crime/offense types



Street-Level Drug Law Enforcement
This practice includes targeted-policing approaches for reducing drug and drug-related offenses. This practice is rated Promising in reducing reported, drug-related calls for services and offenses against persons. This practice is rated No Effects in reducing reported property offenses, public order calls for service, and total offenses.

Evidence Ratings for Outcomes:
Promising - One Meta-Analysis Crime & Delinquency - Drug and alcohol offenses
Promising - One Meta-Analysis Crime & Delinquency - Violent offenses
No Effects - One Meta-Analysis Crime & Delinquency - Property offenses
No Effects - One Meta-Analysis Crime & Delinquency - Public order offenses
No Effects - One Meta-Analysis Crime & Delinquency - Multiple crime/offense types
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Program Snapshot

Gender: Both

Geography: Urban

Setting (Delivery): Other Community Setting, High Crime Neighborhoods/Hot Spots

Program Type: Community and Problem Oriented Policing, Hot Spots Policing, General deterrence

Current Program Status: Not Active

Listed by Other Directories: Campbell Collaboration

Researcher:
Lawrence Sherman
Wolfson Professor of Criminology
Cambridge University
Cambridge CB3 9DA
Phone: 44.0.1223.762094
Email

Researcher:
David Weisburd
Distinguished Professor
George Mason University, Department of Criminology, Law and Society
4400 University Drive, MS 6D3
Fairfax VA 22030
Phone: 703.993.4079
Website
Email