Marijuana Legalization and the California DUI

Posted by Jon Ibanez on September 5th, 2016

It would not be a surprise to many if California was the next state to legalize recreational marijuana with Proposition 64. If approved, California would follow the heels of Alaska, Oregon, Washington, Colorado, and the District of Columbia. California is among five states to vote on the legalization of recreational marijuana this November 8th. As the sixth largest economy in the world and an already existing thriving medical marijuana market, it is estimated that the marijuana industry could become a $6 billion industry by 2020.

In 2010, voters failed to pass Proposition 19, which would have legalized recreational marijuana, by a 53.5% majority of vote. So do California voters have the same sentiment six years later? Current polls show support for the passing of Proposition 64 by 60% or more, making it the initiative most likely to pass on the ballot.

Since Proposition 64 is likely to pass, it would be appropriate to discuss how it might affect California DUIs and California DUI law.

California Vehicle Code section 23152(e) makes it illegal to drive a vehicle while under the influence of drugs including marijuana. Unlike California’s DUI of alcohol law, there is no legal limit for marijuana, or more specifically, tetrahydrocannabinol (THC) the psychoactive component of marijuana. Therefore, a person can only be arrested and convicted of a marijuana DUI if the ingestion of marijuana impairs a person’s ability to drive a vehicle as a sober person would under similar circumstances.

To prove that a person is driving under the influence of marijuana, a prosecutor can use officer observations of driving patterns, observations during the traffic stop, performance on field sobriety tests, and the presence of THC in any blood test done.

Since “under the influence” is an extremely subjective standard, it is often very difficult to prosecute DUI of marijuana cases. This is especially true if the driver refused to perform the field sobriety tests and/or the officer did not observe driving that would be indicative of someone who is under the influence of marijuana.

If proposition 64 is passed, law makers could seek some sort of per se limit for how much THC can be in a person’s blood while driving. Several states have set a per se limit of five nanograms of THC per milliliter of blood. Colorado, has set a five nanogram per milliliter of blood limit to allow for the presumption that a person is “under the influence.” Unfortunately, current per se limits for THC, however, are an inaccurate measure of how impaired a person is.

Unlike alcohol, THC is fat soluble and remains in a user’s system long after they have ingested the marijuana, sometimes by several weeks. This creates the possibility of being arrested with five nanograms of THC in the system weeks after a person has smoked marijuana and well after the “high” is gone. Yet, because the THC is present, a person can either be arrested or, in Colorado, presumed to be under the influence.

In June of last year, Cannabix Technologies Inc., a Vancouver based company announced the testing of a prototype marijuana breathalyzer. The company says that the breathalyzer will be able to test whether a person has ingested alcohol within the past two hours. Although the machine will not test for a quantitative amount of THC, it will provide a timeframe for marijuana usage, which is a better indicator of impairment that nanograms of THC in a person’s blood.

In April of this year, the California state legislature awarded UCSD’s cannabis research center $1.8 million to study THC impairment and develop an accurate roadside test for marijuana impairment.

While an accurate test for marijuana impairment may be in the offing, nothing yet exists to provide lawmakers with the ability to create an accurate per se level. Until that happens, which may be before pot shops open up in January of 2018 if Proposition 64 is passed, law enforcement and prosecutors will have to continue to rely on California’s flimsy standard of “under the influence.”

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