Many critics of marijuana legalization raise concerns that marijuana dispensaries might serve as loci for increased local criminal activity. Now there is empirical evidence that just the opposite occurs.

A new study reported in the September issue of Regional Science and Urban Economics examined local crime rate data from 2013 through 2016 in Denver, Colorado, where legal cannabis sales to adults began in 2014. The researchers reported:

The results imply that an additional dispensary in a neighborhood leads to a reduction of 17 crimes per month per 10,000 residents, which corresponds to roughly a 19 percent decline relative to the average crime rate over the sample period. Reductions in crime are highly localized, with no evidence of spillover benefits to adjacent neighborhoods.

The study found that the majority of the crimes reduced were of a nonviolent nature.There were no changes in the number of cannabis-related crimes near dispensaries, but there was a decrease in the number of crimes related to methamphetamine, cocaine, and heroin. The authors speculated that this may be in part due to the increased presence of law enforcement near dispensaries serving as a deterrent to criminal activity.

The authors stated they did “not find increases in marijuana crimes such as cultivation, possession, or sales nearby,” and no increase in crimes associated with marijuana intoxication, “since there is essentially no change in the number of crimes with marijuana as a ‘contributing factor’ near locations that gain dispensaries.”

A 2017 study in Preventive Medicine with a more limited time range looked at crime rates in South Los Angeles, examining local crime rates in neighborhoods surrounding medical marijuana dispensaries (MMDs), tobacco shops, and alcohol retailers, from January through December 2014. The researchers found no increase in crime rates related to the presence of medical marijuana dispensaries, but an increase in crime surrounding tobacco and alcohol outlets:

Results indicated that mean property and violent crime rates within 100-foot buffers of tobacco shops and alcohol outlets—but not MMDs—substantially exceeded community-wide mean crime rates and rates around grocery/​convenience stores (i.e., comparison properties licensed to sell both alcohol and tobacco).

While these studies should help alleviate concerns raised by marijuana prohibitionists about the effect that legalization may have on local crime, similar arguments are used by those who oppose the creation of Safe Injection Facilities for IV drug users. As I have written here, SIFs have been working to reduce overdoses and the spread of disease since the 1980s in more than 120 cities in Europe, Canada and Australia, and there is an “underground” SIF functioning in the US illegally since 2014. Federal law prohibits Safe Injection Facilities in this country, and the Department of Justice is stifling efforts to establish them in Philadelphia, Seattle, San Francisco, Boston, and New York City.

Among concerns raised by opponents is that they will be a magnet for IV drug users, creating a visual disturbance to neighborhood residents. The counter-argument is that SIFs will actually bring the drug users in off the streets, letting them use their drugs out of the view of young impressionable children and other nearby residents, and will reduce the presence of used needles on the streets and sidewalks.

Another concern is that SIFs may be loci for criminal activity. But, as in the case of marijuana dispensaries, those concerns, while understandable, are not borne out by the evidence. A 2017 systematic review by Canadian researchers reported in Current HIV/AIDS Reports found Supervised Injection Facilities were “associated with improvements in public order without increasing drug-related crime.”

The takeaway from all of this is that bringing drug use out of the darkness of the underground reduces harms to those who don’t engage in drug use as well as those who do.