“Neither the marihuana [sic] user nor the drug itself can be said to constitute a danger to public safety.”
The above statement comes from a 1972 report issued by the National Commission on Marihuana [sic] and Drug Abuse. This panel of experts was created by President Richard Nixon. But rather than embrace the commission’s recommendation to decriminalize cannabis, Nixon instead ramped up his War on Drugs and declared marijuana users: “Public Enemy Number One.”
Background: Marijuana & Crime
So who are these public enemies? Recent polls show that nearly half of all Americans have tried marijuana; there are currently about 50 million cannabis users. Clearly, the “war” didn’t go well in terms of winning hearts and minds. And, despite decades of concerted effort and billions spent, law enforcement agencies have struggled to control the criminal activity associated with the smuggling and sale of illegal drugs.
A turning point in the history of cannabis in the United States came in 1996, when California sanctioned medical marijuana. Thirty-seven more states have since followed suit by passing medical marijuana laws (MMLs) and, in 2023, nearly one in two Americans enjoy lawful access to cannabis products.
In the strictest sense, this shift in the legal landscape drastically reduced crime rates, as millions of otherwise law-abiding Americans were no longer considered criminals for simply consuming marijuana. But playing with labels doesn’t answer the real question:
Does marijuana legalization affect crime rates for things like robbery, rape, aggravated assault, smuggling. and gang violence?
Cannabis Crime Numbers
One of the first studies to assign actual numbers to the effect of MMLs on crime used data from the FBI database to track state-by-state differences in both violent and non-violent crime rates (murder, rape, robbery, aggravated assault, burglary, larceny/theft, motor vehicle theft, and arson) for the years between 1991 and 2006. By that point in time, ten states had passed medical marijuana laws.
The authors write:
Results did not indicate a crime-exacerbating effect of MML on any of the offenses mentioned. Alternately, state MMLs may be correlated with a reduction in homicide and assault rates.
They went on to add:
These findings run counter to arguments suggesting the legalization of marijuana for medical purposes poses a danger to public health in terms of exposure to violent crime and property crimes.
A number of studies released in subsequent years arrived at similar conclusions. A few highlights include:
- A comparison of crime rates for the 10-month period before marijuana first became fully legal in Colorado and the same period after legalization showed a 7.7% decrease in all crimes, including a 1.1% decline in violent crime and an 8.8% decline in property crimes.
- A 2016 study based on state-level crime statistics from 1970 to 2012 indicated that while early de-penalization efforts may have actually increased certain crime rates, legalizing medical marijuana was associated with a 4% to 12% reduction in robberies and burglaries.
- Records for adjacent-state crime rates during the period when marijuana was legal in Washington but still illegal in Oregon found that legalization was associated with a 15-30% reduction in rapes and a 10-20% reduction in thefts in Washington relative to Oregon.
There’s more of the same in the research literature, but no need to belabor the point.
Why Medical Marijuana Laws Reduce Crime
It’s becoming increasingly clear that the adoption of MMLs doesn’t result in new crime waves, and may lead to reductions in certain types of crime. But while researchers have a pretty good handle on the “what,” they are less certain of the “why.” Several have suggested the substitution theory: that increased access to marijuana will result in lower rates of alcohol consumption and hard drug use, both of which have negative effects on violent and property crime.
Legalization may also reduce black market sales and smuggling operations associated with organized crime. In 2019, The Economic Journal reported that after MML adoption by states on the Mexican border, there was as a 12.5% drop in violent crime rates and a 41% decrease in drug-law-related homicides. Additionally, a 2020 report from the Department of Justice showed that seizures of contraband marijuana in traffic stops decreased between 2012 and 2014 by almost 62 percent.
Marijuana legalization may also free up law enforcement resources to pursue other types of crime. Some evidence of this phenomenon comes from the United Kingdom, where marijuana was temporarily de-penalized in 2001.
A recap of this policy reports:
De-penalization shifted police efforts [away from marijuana] towards crime related to hard drugs (e.g., heroin and crack) and non-drug crime. Reallocation of effort led to a 9% decrease in non-drug offenses (e.g., robbery and burglary).
Marijuana Dispensary Data
While the majority of Americans favor marijuana legalization, not everyone is thrilled to have a cannabis shop in their neighborhood. This “not in my backyard” attitude has led to municipal and county restrictions on dispensaries. But as it turns out, this is another case where the numbers don’t match preconceptions.
A 2019 report on the effects of marijuana dispensary openings on local crime found that the opening of a dispensary resulted in a decrease in violent crimes within a half mile of the store. Interestingly, this phenomenon applied to neighborhoods with above-average median incomes. The report also showed that dispensary openings were also associated with a 13% drop in hard drug- and alcohol-related crimes. The authors suggested that this trend might result from legal marijuana sales becoming a substitute for hard drug and alcohol sales.
Another study from the same year looked at pre- to post-legalization changes in crime rates across neighborhoods in Denver, Colorado. By tracking crime at the hyper-local level, researchers determined that the opening of a dispensary resulted in a 19% drop in total crime in the immediate area of the dispensary. The authors explained that this might be the result of increased policing or private security responses in the vicinity of the dispensary.
Another interesting dispensary-related phenomenon was revealed by a study of widespread dispensary closures in the state of California. In 2010, more than 600 dispensaries in the Los Angeles area were shuttered temporarily. By comparing crime rates around closed dispensaries to those still open, the authors determined that there was a significant increase in crime rates within a quarter-mile radius of a closed dispensary, with vehicle break-ins being the most common offense.
But it turns out there may be nothing magical about a dispensary that repels criminal activity. In the same study, the authors noted that restaurant closures result in similar increases in local crime. They didn’t try to draw any specific parallels between these two types of business, but did float the idea that any type of closed business reduces customer activity, lighting, and other security elements that serve as “eyes on the street” to deter criminal activity.
Adding it all up, the short answer to “do MMLs effect crime rates?” comes from a comprehensive review of literature released by the National Bureau of Economic Research. After reviewing all the credible evidence from a range of peer-reviewed research, researchers made the concluding statement:
Studies that examine the effect of medical marijuana law or recreational marijuana law adoption provide strong evidence that legalization reduces non-drug crimes.