DUI & Criminal Defense Blog

Marijuana DUI FAQs

Posted by Mike Donaldson | Aug 22, 2019 | 0 Comments

1. Is there a limit as to how much marijuana can be in a person's system while driving in California?

No. Some states, like Colorado and Oregon, have set limits as to how much delta 9-Tetrahydrocannabinol (THC) can lawfully be in a person's system while driving. California has not done so, and they should not set any such limits. The reason California should not set any THC driving limits brings us to FAQ Number 2.


2. If a blood test reveals THC in a person's system, does that mean they are under the influence of marijuana?

No. In fact, the National Highway Traffic and Safety Administration agrees that the presence of THC in blood is not a reliable indicator of impairment, and ialso not an accurate predictor of recent marijuana use. Here is the quote from the NHTSA study:

THC level in blood (or oral fluid) does not appear to be an accurate and reliable predictor of impairment from THC. Also, when low levels of THC are found in the blood, the presence of THC is not a reliable indicator of recent marijuana use. 

3. If a blood test cannot prove that a person is driving under the influence of marijuana, what evidence do the police typically gather to prove it?

The police are uniformly instructed to perform what is called a Drug Recognition Evaluation. This is essentially a beefed up series of Field Sobriety Tests, that, if done properly, includes the taking of various vital signs and a thorough eye examination.

4. What is the Drug Recognition Evaluation?

It is a 12-Step Process designed by the International Association of Chiefs of Police to determine if people are under the influence of drugs, including marijuana. Our office is intimately familiar with the training that DREs go through, and understand how the procedure should be employed. Drug Recognition Evaluations are routinely employed incorrectly by police who fail to properly follow their training.

5. Does a person have to submit to a Drug Recognition Evaluation and other Field Sobriety Tests?

No, but failure to perform the DRE or field sobriety tests can result in the prosecution using your refusal against you as consciousness of guilt. The best idea may be to ask the police officer if you are required to submit to the DRE or field sobriety tests. If they tell you, “No,” which they should, then exercise your right not to take them. This may allow your lawyer to prevent the prosecution from using your refusal as consciousness of guilt.

6. Can my driver's license be suspended for a marijuana DUI?

If a person pleads guilty to driving under the influence of marijuana in violation of Vehicle Code section 23152 (f) in court, then yes, the Department of Motor Vehicles will suspend the person's license for up to six months for a first offense.

7. Are there defenses to marijuana DUIs?

YES. Below is a list of possible defenses to a marijuana DUI:
    • The police unlawfully pulled you over;
    • The police seized a sample of your blood without a warrant;
    • The police drew your blood in a medically unacceptable manner;
    • The police failed to perform a Drug Recognition Evaluation;
    • The police failed to properly perform a Drug Recognition Evaluation;
    • The blood sample fails to indicate recent marijuana use;
    • The analysis of the blood sample for THC using LC/MS/MS technology failed to specifically identify THC and rule out related compounds that could falsely read as THC, such as cannabidiol (CBD).

Our attorneys have decades of experience defending DUI cases and marijuana DUIs. If you are facing a marijuana DUI charge, feel free to call us for a free consultation.

We understand that being accused of a crime is one of the most challenging times of your life. Rely on us to advocate for your rights and to give you the defense you deserve.

About the Author

Mike Donaldson

Mike is a graduate of Gerry Spence's Trial Lawyer's College, and has lectured new attorneys at the Riverside County Public Defender on DUI Defense. Mike is the President of the Southwest Riverside County Bar Association, and a part-time professor of Political Science at Mt. San Jacinto College.


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