Study: No Uptick in Violent Crime Following Adult-Use Cannabis Legalization

Pullman, WA: The enactment of statewide legislation permitting adult cannabis possession and sales is not associated with any significant or long-term uptick in criminal activity, according to data published in the journal Justice Quarterly.

Investigators affiliated with the Department of Justice and Criminology at Washington State University assessed trends in monthly average crime rates in Colorado and Washington following legalization compared to various control states. Researchers specifically examined trends in violent crime, property crime, aggravated assault, auto theft, burglary, larceny, and robbery rates.

They reported, “[M]arijuana legalization and sales have had minimal to no effect on major crimes in Colorado or Washington. We observed no statistically significant long-term effects of recreational cannabis laws or the initiation of retail sales on violent or property crime rates in these states.”

Consistent with the results of prior studies, the authors concluded, “[T]he results related to serious crime are quite clear: the legalization of marijuana has not resulted in a significant upward trend in crime rates. … Our results from Colorado and Washington suggest that legalization has not had major detrimental effects on public safety.”

Full text of the study, “The cannabis effect on crime: Time-series analysis of crime in Colorado and Washington State,” appears in Justice Quarterly. Additional information is available from the NORML fact-sheet, “Marijuana Regulation and Crime Rates.”