Fact Check

Is Marijuana Responsible for Colorado Crime Increase?

Denver District Attorney Mitchell Morrissey published a letter painting a bleak picture of marijuana for an anti-legalization campaign.

Published Nov 2, 2016

 (Tanjila Ahmed)
Image Via Tanjila Ahmed
Marijuana legalization has led to an increase in crime and fatalities all over Colorado.

On 18 October 2016, the Citizens Against Legalizing Marijuana (CALM) political action committee published a letter from Denver District Attorney Mitchell Morrissey claiming that the drug has fueled a crime increase around Colorado.

The letter urges California voters to reject state Proposition 64, which would legalize recreational marijuana use for adults 21 and over and is on the state ballot on 8 November 2016.

Morrissey opens his argument by citing statistics taken from a September 2016 report by the Rocky Mountain High Intensity Drug Traffic Area (HIDTA), part of a federal program coordinating anti-drug efforts among federal, state, and local law enforcement agencies.

Morrissey's letter stated that — according to the HIDTA report — after recreational marijuana use was legalized in Colorado in 2013, "traffic related marijuana deaths" went up by 48 percent while "marijuana related emergency room visits" increased by 49 percent.

But the report lists qualifiers that are not mentioned in the letter:

Driving Under the Influence of Drugs (DUID): DUID could include alcohol in combination with drugs. This is an important measurement since the driver’s ability to operate a vehicle was sufficiently impaired that it brought his or her driving to the attention of law enforcement. Not only the erratic driving but the subsequent evidence that the subject was under the influence of marijuana helps confirm the causation factor.

Marijuana Related: Also called “marijuana mentions,” is any time marijuana shows up in the toxicology report. It could be marijuana only or marijuana with other drugs and/or alcohol.

Marijuana Only: When toxicology results show marijuana and no other drugs or alcohol.

It also states:

This report will cite datasets with terms such as "marijuana related" or "tested positive for marijuana." That does not necessarily prove that marijuana was the cause of the incident.

The report goes on to say that 105 out of 871 state motorists involved in fatal crashes in 2015 tested positive for marijuana, accounting for 12 percent. Of those 105 drivers, 33 percent only had marijuana in their system. Another 30 percent tested positive for both alcohol and marijuana, though the study did not mention the proportion of that mixture. HIDTA did not identify motorists who only had alcohol in their systems at the time of their collisions.

Morrissey's letter also cited statistics taken from the Colorado Bureau of Investigations' statewide crime report for 2015. But while it correctly notes that homicides went up by 14.7 percent in the state in 2015 compared to 2014, the CBI's findings make no mention of the drug.

The district attorney also suggested that Pueblo's state-high homicide rate (11.1 killings per 100,000 residents) was linked to marijuana legalization. But local police attributed the recent increase in local homicides (13 per year in 2014 and 2015) to a combination of lower staff levels and an "explosion" in the use of opioids like black-tar heroin.

Similarly, the letter stated, the homicide rate in Aurora more than doubled between 2014 and 2015. While this is accurate — there were 23 killings in the city in 2015 compared to 11 the year before — Deputy Police Chief Paul O'Keefe said in April 2016 that the former number was "back to average" for the city.

An internal memo attributed to Aurora Police Capt. Christian Lertch did blame that surge (as well as increases in robberies, assaults, and aggravated assaults) to "face-to-face marijuana deals that have 'gone bad.'" But other department officials reportedly also cited a higher population and low police staffing as factors that contributed to the crime increase.

Morrissey, whose tenure as district attorney ends in 2016, has denied penning the letter for political reasons, but also accused pro-marijuana activists of getting "outraged" when presented with what he called the facts regarding the effects of legalization:

What I was trying to do was accurately reflect the facts as we know them since we have legalized commercial marijuana.

In July 2013, Morrissey made a more pointed claim about the issue at a local city council meeting:

We have had 12 homicides related directly to medical marijuana. We have had over 100 aggravated robberies and home invasions. Many of you probably didn’t read about the double-execution-style homicide that we had here in Denver, where people were laid down on the floor and executed because they were running a medical marijuana outlet.

He later backed away from that statement, saying it was based on "loose figures."

We contacted police in both communities, and the CBI seeking comment, but have yet to hear back.

A spokesperson for Morrissey's office sent this statement to snopes.com on 2 November:

The letter you reference was written in response to two questions that were asked of Mr. Morrissey as it relates to legal marijuana – has crime gone down in Denver and Colorado, and have law enforcement resources been freed up to focus on other crimes.

He simply answered those two questions.

His source for the information in his letter included local Denver media reports, the most recent published report from the Rocky Mountain High Intensity Drug Trafficking Area, and information he received directly from the Denver Police Department Marijuana Enforcement Unit, Denver Police Department Crimes Against Persons Division, and the Denver Crime Lab.

Mr. Morrissey takes no political position on any ballot measure in any other state regarding this issue.

Arturo Garcia is a former writer for Snopes.