Program Profile: Minneapolis (MN) Hot Spots Experiment

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.

An Effective rating implies that implementing the program is likely to 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/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 people from committing crime.

Study

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.

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

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

Following are CrimeSolutions-rated programs that are related to this practice:

Hot Spots Policing

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

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 Ineffective in reducing reported property offenses, public order calls for service, and total offenses.

Evidence Ratings for Outcomes

	Crime & Delinquency - Drug and alcohol offenses
	Crime & Delinquency - Violent offenses
	Crime & Delinquency - Property offenses
	Crime & Delinquency - Public order offenses
	Crime & Delinquency - Multiple crime/offense types

Why might a practice's outcome ratings differ from the ratings of specific programs encompassed by that practice?