Examining the effects of pot legalization on law enforcement

Staff Writer

Washington State University researchers are undertaking a $1 million, three-year study of how the state’s legalization of marijuana has affected law enforcement and crime.
The study will look at state, county and tribal police jurisdictions, as well as policing in neighboring states.

Mary Stohr, principal investigator and professor of criminal justice and criminology, said legalization has created a “great natural experiment” for studying the effects of changing marijuana policies on law enforcement and society in general.

“There are plenty of people starting to look into this area because it has such a huge potential impact on our communities and families and because it’s a retreat from the war on drugs,” Stohr said.

On the ground

“Our investigation will look at the people with the boots on the ground in that war, the folks who actually have to deliver policy and have to interact with the public and deal with the implications of the policy.”

The study could lead to a set of law enforcement “Best Practices” and will be instructive to other states that legalize cannabis, said Dale Willits, a co-investigator and assistant professor of criminal justice and criminology.

“They don’t have to go into a blind,” Willits said. “They can say, ‘Here’s what agencies in Washington tried. These things really don’t work. And these things really did work.’ And they can use that as a jumping off point.”

Washington voters approved Initiative 502 in 2012, legalizing small amounts of marijuana for adults 21 and older. Colorado passed a similar measure the same year. Another five states—Arizona, California, Maine, Massachusetts and Nevada—have adult-use measure on the ballot in November.

Funding for the research is coming from the National Institute of Justice, a research agency of the U.S. Department of Justice.

The study will compare how law enforcement handled crime and offenders, particularly those involving marijuana, before and after legalization. It will examine the effects of legalization on crime, clearance rates (crimes that result in charges), and other activities across the state, as well as in urban, rural, tribal and border areas.

As the researchers note in their grant application, supporters of I-502 claimed legalization would reduce crime and the numbers of people in jail and prisons while focusing limited resources from law enforcement on more serious crimes.

Opponents said legalization would increase marijuana use by minors and increase the incidence of drug-impaired driving.

Evidence mixed

So far, the evidence of I-502’s impact has been mixed.

According to research collected by the Northwest High Intensity Drug Trafficking Area, a federal anti-drug program, Spokane police have found that possession and theft crimes have increased since commercialization, while the Seattle Police Department has indicated that marijuana-related incidents have decreased for both adults and juveniles since legislation.

Seizures of pot during traffic stops dropped by more than half between 2012 and 2014, according to the Northwest High Intensity Drug Trafficking Area. However, the program has seen a doubling of the percentage of drivers involved in fatal accidents with THC, marijuana’s main active ingredient, in their blood. It is noted that could be the result of increased testing.

Marijuana-related traffic arrests could go down as legalization has created a higher threshold for police to act, said Craig Hemmens, another co-investigator and chair of the WSU Department of Criminal Justice and Criminology. Legalization could also be freeing police up for other work, he said.

“If they’re not spending time booking people for marijuana possession, maybe they can spend more time on heroin dealers or crack dealers, or burglaries or something else,” Hemmens pointed out.


The researchers plan to attack their project three ways. They will conduct in-depth case studies of 10 agencies using historical and statistical information, interviews, focus groups and an analysis of camera footage. A second tier of research will analyze arrests, reported crimes, crime clearance rates and traffic stops in the 10 jurisdictions both before and after implementation of I-502.

The third tier will involve a similar analysis for cities, counties and statewide in Washington, Idaho and Oregon.