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Marijuana Legalization and Crime Clearance Rates: Testing Proponent Assertions in Colorado and Washington State

NCJ Number
Date Published
25 pages
In order to assess the effects on crime of the legalization of recreational cannabis in Washington state (I-502) and Colorado (A-84), the current study used 2010 to 2015 Uniform Crime Reports data and interrupted time-series analysis on the offenses known to be cleared by arrest to create monthly counts of violent and property crime clearance rates, as well as disaggregated counts by crime type.
The legalization of recreational cannabis in Washington state and Colorado created a natural experiment with ancillary unknowns. Of these unknowns, one of the more heavily debated is that of the potential effects on public health and safety. Specific to public safety, advocates of legalization expected improvements in police effectiveness through the reduction in police time and attention to cannabis offenses, thus allowing them to reallocate resources to more serious offenses. Findings of the current study suggest no negative effects of legalization on crime clearance rates. Moreover, evidence suggests some crime clearance rates have improved. The findings suggest legalization has resulted in improvements in some clearance rates. (publisher abstract modified)

Date Published: January 1, 2019