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Does Patrol Prevent Crime? The Minneapolis Hot Spots Experiment

NCJ Number
L W Sherman; D Weisburd
Date Published
16 pages
The Minneapolis Hot Spots Experiment assessed the impact of police patrolling on crime prevention and tried to compensate for design problems in previous studies, notably inadequate sample size, no measurement of patrol intensity, and dispersal of patrol units over too broad a low-crime area.
This study used a sample size of 110, with 55 hot spots in each treatment group; it measured patrol presence through officer records and research staff observation; and it concentrated the experiment in the highest crime hot spots in Minneapolis. The preliminary analysis showed that extra patrolling can make a difference in the rate of crime occurring in a specific hot spot, although most of the time, routine patrol levels may only produce a modest reduction in crime. Future study is needed to determine whether greater increases in patrols would yield greater reductions in crime. Patrol increases can provide a kind of residual deterrence, preventing crime and disorder from occurring in hot spots even after the police are gone. 3 notes and 21 references