Study: Cannabis Legalization Has No Impact on Theft and Violent Crimes

Despite long-held assumptions that legal cannabis is bound to increase theft and violent crimes, a new study indicates otherwise. The National Institute of Justice (NIJ) has published a report in Justice Quarterly analyzing crime statistics tracked by the Federal Bureau of Investigation (FBI). The study looked at crime data from 1999-2016.

In Colorado and Washington, violent crime and theft rates showed no statistically significant rise after 2014, the first year of legal recreational cannabis sales. While the debate may not be over, so far, things are looking good for legal cannabis.


“In many ways, the legalization of cannabis constitutes a grand ongoing experiment into how a major public policy initiative does or does not accomplish its expected outcomes,” Ruibin Lu, the study’s lead author said. “Given the likelihood of more states legalizing recreational marijuana, we felt it was important to apply robust empirical methods to parse out the effects of this action on crime in the first years after legalization.”

Previous research has concluded legal cannabis sales can cause a rise in theft and violence. However, many researchers feel these studies are based on anecdotal evidence and are unable to view crime data over the long-term. A recent study found the presence of cannabis dispensaries actually reduced crime by 19 percent, though there may not be enough data available to accept this as a universal conclusion.

NIJ study co-author, Dale Willits, wants to urge caution before making assumptions about how legal cannabis may impact other crimes. For instance, this study did not analyze whether or not driving under the influence convictions rose after legalization.

The study may not be the definitive word on legalization’s impact, but the doomsday scenarios predicted by cannabis opponents do not seem to be coming to fruition. 

“I think it will be pretty clear evidence that, at a minimum, the sky isn’t falling,” Willits said.

There are other limitations to the study. In addition to the exclusion of DUI data, the study relies solely on the FBI’s uniform crime reporting system. This system only records the most serious charge when multiple violations are committed, leaving open the chance that some offenses were not included in the study. Also, researchers did not account for violations committed by minors.

Willits realizes more research must be conducted before a concrete conclusion can be reached.

“We really need to see where this goes. Right now we said, no short-term effects. And that’s really all we can say with the data we have. But I wouldn’t feel comfortable saying, in ten years, we won’t see some benefit or cost from this we didn’t anticipate.”