Marijuana DUI in California: What to Expect & Legal Consequences

Although most DUIs in California involve driving under the influence of alcohol, the offense can also include driving under the influence of drugs. Drugs in this context is broad enough to include not just illegal drugs like heroin, but prescription drugs like opioids and legal drugs like marijuana, which is also known as cannabis. Here is an overview of the law on marijuana DUIs in California, including Los Angeles.

The same statute that makes driving under the influence of alcohol illegal in California also makes driving under the influence of drugs illegal. California Vehicle Code section 23152(f) states: "It is unlawful for a person who is under the influence of any drug to drive a vehicle."

The statute is inclusive in that it applies to any drug. The term is defined in the California Judicial Council criminal jury instructions as follows: A drug is a substance or combination of substances, other than alcohol, that could so affect the nervous system, brain, or muscles of a person that it would appreciably impair his or her ability to drive as an ordinarily cautious sober person, in full possession of his or her faculties and using reasonable care, would drive under similar circumstances.

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Under this definition, illegal drugs like cocaine, heroin and methamphetamine are included, but also over-the-counter medications like cold syrup and prescription drugs. This could include opioids like Oxycontin and Vicodin​,​ as well as sleeping medications like Ambien​.​ Marijuana is another drug included in the DUI statutes; although it is legal to buy and use marijuana in the state, it is still illegal to drive under the influence of marijuana.

Police and prosecutors are more concerned about people driving under the influence of marijuana now than when it was illegal since more people will feel free to use the drug.

Marijuana DUIs are one of the most common type of drug DUI charged in California. It's easy to think that because marijuana is now legal in the state, including medical marijuana and recreational marijuana, police aren't concerned about stopping people for marijuana DUIs. However, the opposite is true. Police and prosecutors are more concerned about people driving under the influence of marijuana now than when it was illegal since more people will feel free to use the drug.

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California drivers are familiar with the state's 0.08 percent legal limit for blood alcohol concentration (BAC). If chemical testing, like a breathalyzer, blood test or urine test, reveals a BAC of 0.08 percent or greater, the driver is said to be above the legal limit for alcohol. No further proof of driving impairment is required.

There is no equivalent legal limit for marijuana in California. While blood tests and urine tests can determine the amount of a drug in the bloodstream, nobody is certain what concentration of marijuana would impair a driver. That is, experts can't link specific drug concentration levels to driver performance. That means that in every DUI drug case, the prosecutor must prove actual impairment, such as delayed reaction time.

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The police cannot distinguish between a DUID driver and a DUI driver simply by watching the way they drive. That is, like someone driving under the influence of alcohol, someone driving under the influence of marijuana might also drive erratically, swerve or veer from one lane to another, make illegal turns, hit the breaks for no obvious reason, or drive too fast or too slowly.

When police officers or law enforcement stop a driver for this type of conduct, they usually first check for alcohol impairment, asking about the driver's alcohol use and administering a preliminary alcohol screening (POS) breathalyzer. However, if the driver has been smoking marijuana in the car, the police officers are likely to smell it. In that case, the officers may ask about marijuana use and administer a mouth swab test to check for marijuana. They also do this if the driver's breath test shows a BAC of under the legal limit, but there are other signs of intoxication.

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If the driver refuses the mouth swab, or the swab indicates drug use, the police officer may ask for a drug recognition evaluator or drug recognition expert (DRE) to come to the scene. This is only possible in counties that have these specialists. A DRE is a police officer trained to recognize signs of drug intoxication. The California Highway Patrol runs the training and certification program.

When a DRE arrives, they take over the DUID case and conduct their own evaluation. The DRE's evaluation has 12 steps, starting with confirming that the driver's BAC is under the legal limit. Just as a driver (21 years or older) has the absolute right to refuse to take a POS breathalyzer, they can refuse to answer any of the DRE's questions.

However, if the DRE has probable cause to believe the driver is driving under the influence of marijuana or any other drug, the driver may be arrested and taken to the police station. At that stage, they no longer have the right to refuse chemical testing and will forfeit their driving license for a year if they do.

The 12 steps include monitoring the driver's pulse, pupils and muscle tone, since drugs can cause muscle rigidity. The DRE also checks for needle track marks on the driver's body and drug traces in the mouth or nose, and looks for an involuntary jerking of the eye that suggests drug use.

The key thing they’re looking for in these marijuana DUIs is whether the driver can safely operate a motor vehicle. The DRE's job is not to figure out whether the driver has ever used marijuana or even if they used marijuana that day, but rather whether the person is currently under the influence of marijuana and whether it is impairing their driving abilities. The active ingredient in marijuana, tetrahydrocannabinol (THC), stays in a person's system for some time after marijuana use, so the mere presence of THC their system or THC levels higher than normal are not enough evidence.

After the 12-point evaluation is completed, the DRE gives an opinion about whether the driver is driving under the influence of marijuana. They also offer an opinion as to whether the driving was impaired. The strongest evidence of marijuana impairment will usually come from the blood test.

In California, the police cannot take a blood test from a driver without their permission unless they obtain a warrant. In order to get a warrant for a DUI arrest, the police must have reasonable cause to believe that the driver was DUID and have a "clear indication" that a blood test will reveal evidence of the person being under the influence.

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After a driver is arrested for DUID and a blood sample is taken, it is sent out for a DUI blood toxicology screen. If there are drugs in the driver's blood, the screen will list them, but generally not their concentration – an additional lab analysis identifies the amount of the drug in the driver’s system. In the case of marijuana, this substance is THC.

Urine testing is used less often in a marijuana DUI case. One reason is that urine tests do not detect THC, but rather inactive metabolites associated with the use of marijuana. However, these only indicate marijuana use, they do not show impairment and they can show up in urine long after the person used marijuana.

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California's DUI laws include a threshold BAC, usually 0.08 percent, at which the person is deemed "per se" impaired. This means that if the test shows a BAC over the legal limit, the prosecutor does not have to prove impairment. However, California’s DUID law does not set a similar threshold for marijuana, given the disagreement between experts as to what concentration of drugs would impair a driver.

A prosecutor arguing a DUID must convince the jury through testimony from the police officer, the DRE and any witnesses that the person's driving abilities were impaired by the drug use. For example, they may testify about erratic driving behavior, or that the driver, when stopped by the police, showed objective signs and symptoms of intoxication like red eyes, slurred speech or an unsteady walk. They might also describe, or show videos of, what happened on the field sobriety tests.

In California, criminal charges are either infractions, misdemeanors or felonies. Infractions are the least serious crimes and are never punishable by imprisonment. Misdemeanors are lesser crimes that carry a maximum penalty of one year in county jail. Felonies are the most serious crimes, defined as any crime that carries a punishment of over one year in prison.

The consequences for driving under the influence of marijuana are the same as for driving under the influence of alcohol. In criminal law, a DUI of any kind, whether involving alcohol or drugs, counts as a prior conviction in a subsequent DUI prosecution.

Most DUIs are charged as misdemeanors, whether alcohol or drug based. They may be charged as felonies if the driver has multiple prior convictions or if damage or injury results from driving while impaired.

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The first time a person is convicted of a simple marijuana DUI, the penalties usually do not include jail time. Instead, the judge typically sentences the convicted driver to informal DUI probation of three to five years; a fine of $390 or more, plus penalties and assessments; a Department of Motor Vehicles (DMV) driver's license suspension for at least six months; and a three-month drug education class, known as California DUI school.

If the driver gets additional DUI convictions, whether for alcohol or drugs, within a 10-year period, the penalties increase. That is, second offenses will result in greater fines, more probation and DUI school time than for a first offense, and include some mandatory jail time. A third offense brings even greater penalties than the second. The driver’s license suspension period is also longer with each new DUI offense.

A fourth DUI within a 10-year period is usually charged as a felony. This means that the sentence will include over a year in state prison in addition to fines and loss of license. This is a much more serious conviction that can have implications for a person's future. State prison time is considered much harder than county jail time, and the driver may face life-long repercussions resulting from the felony conviction.

Even without prior convictions, a marijuana DUI can be charged as a felony if another person is injured as a result of the person's impaired driving. For example, if the driver under the influence hits a pedestrian or causes an accident that injures a passenger in their car or another car, the case can be tried as a felony. If the injured person dies as a result of the accident, the driver can be charged with murder.

Causing injury while driving under the influence is a "wobbler" offense in California. This means that the prosecutor can opt to charge it as a misdemeanor or a felony, depending on the circumstances.

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If the driver is arrested for marijuana DUI, they do not have the right to refuse to take a blood or urine test for drugs. If the person does refuse, they will automatically have their license suspended for one year for a first offense.

If they are convicted of the marijuana DUI despite their refusal to take the test, the driver faces a mandatory county jail sentence of at least 48 hours. This is a heavy sentence compared to the typical penalty for a first offense DUID, which is no jail time and a six-month driver's license suspension.

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