The facts are in: legalizing medical marijuana does not increase crime rates, according to historical crime statistics. The results of a study conducted by researchers at the University of Texas, Dallas, show that not only do crime rates not increase in states that legalize pot, the rates of certain crimes tend to drop. As the researchers concluded in the study, legalization “may be correlated with a reduction in homicide and assault rates” in some areas.

The study results are published in a March 26 article in the journal PLOS One. They analyze the association between medical marijuana legalization and state crime rates for all Part I offenses in the FBI’s Uniform Crime Report (UCR) for the 11 states that legalized medical marijuana between 1990 and 2006. As the Washington Post notes in a March 26 article, crime across the US was already “broadly falling” during this time period, but the study took a closer look and was able to conclude that there was no recognizable increase in crime in any of those states following legalization. The study looked specifically at the differences between the 11 states, as well as the differences within each of those states before and after legalization. It controlled for outside influences on crime rates, including income and education levels, employment and poverty rates, urban demographics, age, the number of police officers on duty and per capita prison inmate population. It also factored in beer consumption per-capita using data from the Beer Institute.

There was no increase in homicide, rape, robbery, assault, burglary, larceny, or auto theft.

The study’s researchers concluded that the reasons crime didn’t spike in medical marijuana states might have to do with the inherent cultural attitudes in areas that legalize marijuana:

“Perhaps the more likely explanation of the current findings is that [medical marijuana] laws reflect behaviors and attitudes that have been established in those societies. If these attitudes and behaviors reflect a more tolerant populace that is less likely to infringe on one another’s personal rights, we are unlikely to expect an increase in crime and might even anticipate a slight reduction in personal crimes.”

Marijuana dispensaries make no secret that they’re chock-full of an expensive, federally illicit substance, so it’s common sense—at least for someone searching for an argument against legalization—to assume that robberies or burglaries might increase near those facilities. The fact that those crimes did not increase is significant.

As the Washington Post article notes, also interesting is the fact that homicide and assault rates actually tend to decrease near dispensaries. In their analysis of the study, the researchers state that this change might just be a statistical artifact of their analysis. They also note it’s possible marijuana legalization leads to decreased alcohol consumption, which has been proven to influence assault and homicide rates: