Study: Police solve more violent crimes after cannabis legalization

The legalization of cannabis for adult use is associated with higher clearance rates various types of violent crime, according to a study soon to be published in the’International Journal of Drug Policy.

Researchers from the University of Utah and the University of China examined crime clearance rates in Oregon and control states before and after the legalization of cannabis for adult use.

The violent crime clearance rate represents the proportion of solved violent crimes - i.e., where an arrest is made and charges laid - in relation to all violent crimes reported to the police.

The researchers found «significant increases in clearance rates for overall violent crime and aggravated assault in post-legalization Oregon counties compared to those in states where cannabis is not legal.».

Entitled Recreational marijuana legalization on clearance rates for violent crimes: Evidence from Oregon, However, the article found that the positive effects of legalization on clearance rates «appear to diminish over time». Further research is also needed on the effect of adult-use cannabis legalization on police performance and clearance rates, the investigators wrote.

A 2018 study already noted a similar increase in violent crime clearance rates after cannabis legalization in Washington and Colorado.