Marijuana Legalization for Medical Use Does Not Increase Crime, Says Study


Researchers in Dallas at the University of Texas found that legalizing medical marijuana use does not increase crime. More so, the study also says that in some instances it may decrease crime altogether. The study was published in PLOS One on Wednesday.

The researchers led by Robert Morris, an associate professor of criminology, looked at all of the 50 states and their crime rates between 1990 to 2006, a 16-year period that saw 11 states legalize medical marijuana. In particular Part I crimes were examined, which the FBI includes as rape, homicide, robbery, burglary, auto theft, aggravated assault, and larceny. Data came from FBI Uniform Crime Reports, states websites, the census, The Bureau of Economic Analysis, the Beer Institute, and the Bureau of Labor Statistics.

Other variables known to be linked to crime rate, such as poverty, unemployment, and education,  were factored into the study and a rise in crime was still not found in relation to the legalization of medical marijuana. For some states, the legalization may have helped to decline homicide and assault, though Morris makes it clear this point, as interesting as it is, is not the focus of the study. Nevertheless, the findings are contrary to the belief held by cannabis opponents who say that approving the substance could lead to an increase in crime.

There are many researchers who say that violent behaviour exhibited by some marijuana users is resulted from its illegality rather than the substance itself. The results that suggest legalization of marijuana for medical use does not increase crime, though there no direct link, supports this claim –  point brought to the forefront by Morris in talking about the study.

In fact, various reports have found more of a link between violent crime and other substances, in particular alcohol. A  National Institute on Alcohol Abuse and Alcoholism report found there were 2.7 million victims each year from violent crimes caused by alcohol, which is equal to almost one in four of the total number of victims of violent crimes in the U.S.

Another report from 2003 in the Addictive Behaviours journal explored various substances and their causal relationship to violence. The study noted how alcohol and intoxication has the most direct relation to violence based on a collection of evidence. On the other hand, researchers conducting the study also found that marijuana helped reduce violence when one is intoxicated. Echoing these results are findings in the National Academy of Sciences, as written in Beau Kilmer’s book Marijuana Legalisation: What Everyone Needs to Know, which found that THC, pot’s active ingredient, led to a decrease in aggressive behaviour among chronic cannabis users. The book also looked at another study which found that drug use and crime has more of a relation to hard drugs such as cocaine, crack, and heroine over marijuana.

Today, there are 20 states who have legalized marijuana for medical use and two, Washington and Colorado, who have legalized it for recreational purposes. More states are likely to follow in an American culture that is starting to become more aware of the benefits of marijuana.

The researchers plan to study the relationship between legalization of marijuana in regards to recreational use, now that it has been approved in Washington and Colorado. Morris says these current findings, which suggests medical marijuana legalization does not increase crime, are “remarkable.” He also expressed an anticipation to see what results will come out of following studies in the near future.

By Kollin Lore


The Huffington Post
National Institute of Alcohol Abuse and Alcoholism
National Institute of Alcohol Abuse and Alcoholism 2
Addictive Behaviours
Nature World News
Marijuana Legalization Book

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