Advocates have been preaching it since marijuana was in full prohibition and now there is research to put proof behind it, legalizing cannabis frees up police to solve more serious crimes. In a recent analysis of crime data in both Colorado and Washington there is a clear indication of the time that both states began cannabis prohibition reform and the increase in other crimes being solved in both states. While the crime data alone is not enough to say that marijuana legalization increases crime clearance, when coupled with the knowledge that no other major policy changes happened in that time frame that would effect crime clearance, researchers say it is plausible that marijuana legalization alone was the primary factor. It's also important to note that researchers examined no negaitve effects of legalization when looking at the crime data.
Marijuana legalization in Colorado and Washington state has “produced some demonstrable and persistent benefit” to police departments' ability to solve other types of crime, according to researchers at Washington State University.
“Our models show no negative effects of legalization and, instead, indicate that crime clearance rates for at least some types of crime are increasing faster in states that legalized than in those that did not,” the authors write in a study published in the journal Police Quarterly.