Evidence-Based Policing Matrix
Micro Places – Cohen et al. (2003)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Micro places; Focused; Proactive; Moderately Rigorous; Mixed effects
What police practice or strategy was examined?
This study examined the effectiveness of police raids on reducing illegal drug dealing in and around nuisance bars in Pittsburgh, Pennsylvania. Believing that nuisance bars and drug activity were linked, the Pittsburgh Police Department established the Nuisance Bar Task Force, which involved prosecutors, liquor control, code enforcement agencies, and community representatives. In response to complaints about disruptive bars, plain-clothes detectives periodically surveilled certain bars to confirm allegations of drug dealing and other significant public order issues to determine whether the bar could be considered a nuisance. Once identified as a “nuisance bar,” it became a target of police raids by the narcotics squad from January 1990 to December 1992, while there were no similar raids at non-nuisance bars during the periods. A typical raid involved detectives entering the premises and adjacent areas and confiscating any visible drugs and contraband. The bars were also checked for compliance with liquor regulations, such as maintaining a valid license, prohibiting sales to minors, and enforcing sales hours. Violations of liquor laws and public order, such as consuming alcohol on public streets, were cited, and some individuals faced arrest for drug-related offenses.
How was the intervention evaluated?
This study evaluated (1) the time-varying effects of police raids and (2) how ecological risk factors related to land use and population characteristics influence the intervention's impact on drug dealing within and near the targeted areas. To evaluate the effectiveness of the raids, trends in drug-related calls for service in micro areas (1/8th mile radius) around 37 nuisance bars were compared with those around 40 non-nuisance bars. Given that areas around non-nuisance bars could differ from those around nuisance bars, the authors tried to isolate the treatment effects by meticulously controlling for a range of place-level factors related to illegal drug dealing. These include land use risk factors, such as the percentage of vacant housing units and commercial properties, as well as guardianship risk factors, such as the adult-to-youth ratio.
What were the key findings?
Police raids in and around nuisance bars suppressed drug activity around those bars, but only during the raids, with effects vanishing afterwards. Furthermore, the higher the risk of crime and disorder near nuisance bars, the less effective the raids were.
What were the implications for law enforcement?
Raids in and around nuisance bars only produce a very short-term deterrence effect on drug activity. To sustain the reductions in drug dealing activities, continuous enforcement may be necessary. Additionally, understanding and addressing contextual risk factors are crucial for designing effective police raid interventions, as environmental and guardianship conditions can reduce the effectiveness of these raids further.
Where can I find more information about this intervention, similar types of intervention, or related studies?