Adult use marijuana laws are not associated with an uptick overall criminal activity
"There is evidence in this table that the legalization of recreational cannabis enacted in Washington caused a decrease in crime rates. The point estimates for rape, assault, robbery, burglary and theft are all negative. This conclusion is reinforced by the statistical significance of the drop in rapes and thefts. ... Our estimates reveal that the legalization decreased ... both ordinary alcohol and binge alcohol. ... These effects on consumption suggest that one of the mechanisms underlying the reduction in crime may be a substitution away from other drugs ... such as alcohol, which makes consumers more aggressive than if consuming cannabis."
"Since voters approved Initiative 502, FBI crime statistics show lower rates of violent crime in Washington than before legalization. According to the FBI data, in 2011 there were 295.6 violent offenses reported per 100,000 Washington residents. In 2015, the most recent full year of data available, that rate had fallen to 284.4 violent offenses per 100,000 people."
"[M]onthly crime rates from Denver, Colorado ... remain essentially constant after 2012 and 2014. ... Other cities in Colorado mirror those findings. ... [In Seattle, Washington,] both categories of crime (violent crime and property crime) declined steadily over the past 20 years, with no major deviations after marijuana liberalization. ... Monthly violent and property crime remained steady after legalization in Portland, Oregon. ... Elsewhere in Oregon, we see no discernible changes in crime trends before and after legalization or medical marijuana liberalization."
"[V]iolent crime and property crime in Denver ... dropped 10.6 percent [following legalization] compared to that same span one year earlier.. Homicides have dropped to less than half of last year's levels, and motor vehicle theft has shrunk by over one-third."
Medical cannabis regulatory laws are not associated with an uptick overall criminal activity
"We do not find evidence that medical marijuana laws consistently affect violent and property crime. ... Our results suggest that liberalization of marijuana laws is unlikely to result in the substantial social cost that some politicians clearly fear."
"The central finding gleaned from the present study was that MML (medical marijuana legalization) is not predictive of higher crime rates and may be related to reductions in rates of homicide and assault, ... [R]obbery and burglary rates were unaffected by medicinal marijuana legislation, which runs counter to the claim that dispensaries and grow houses lead to an increase in victimization due to the opportunity structures linked to the amount of drugs and cash that are present. .... [T]his is in line with prior research suggesting that medical marijuana dispensaries may actually reduce crime in the immediate vicinity."
Retail cannabis facilities are not positively associated with increased criminality, and may play a role in the prevention of certain crimes, like larceny
"The results presented above show that temporary dispensary closures increase crime in the short-run. ... Analyzing medical marijuana dispensary closures in the City of Los Angeles, we find no support for the idea that closing dispensaries reduces crime. Rather, temporary closures deter some types of Part I crime. ... Our findings have direct policy implications for regulating marijuana sales in the U.S. They imply that dispensary closures, and potentially the closure of other types of retails establishments, exert a significant negative externality in terms of neighborhood criminality. A quick back of the envelope cost calculation using the change in larceny theft at 1/3 of a mile and crime costs ... suggests that an open dispensary provides over $30,000 per year in social benefit in terms of larcenies prevented."
"There were no observed cross-sectional associations between the density of medical marijuana dispensaries and either violent or property crime rates in this study. These results suggest that the density of medical marijuana dispensaries may not be associated with crime rates or that other factors, such as measures dispensaries take to reduce crime (i.e., doormen, video cameras), may increase guardianship such that it deters possible motivated offenders."