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Micro-Deterrent Effects of Police Raids on Crack Houses: A Randomized, Controlled Experiment

NCJ Number
Date Published
41 pages
The block-level micro-deterrent effects of uniformed police raids of crack houses in Kansas City, Missouri, were tested using a study design that focused on indicators of public order and safety.
These indicators were limited to offense reports and calls for police service. Data were obtained from blocks with at least 5 calls for police service in the 30 days preceding an undercover crack buy. The sample included 207 cases out of a total of 1,421 attempted buys by undercover police officers. Raids were randomly assigned to 104 locations and carried out at 98 locations, with the other 109 locations left alone. Experimental blocks, relative to controls, showed reductions in both calls for police service and offense reports. These effects, however, were quite small and decayed within 1 to 2 weeks. Raids in which arrests were made, 23 of 104 assigned, had no consistently different impact from raids in which no arrests were made. Raids had more impact on calls for police service in the winter than in the spring, but little seasonal differences were found in raid effects on offense reports. The authors conclude alternative police methods may be far more cost-effective in harm reduction for crack houses. 51 references, 3 tables, and 3 figures

Date Published: January 1, 1995