Driving Under the Influence of Marijuana

On January 1, 2018, California passed Proposition 64, legalized the possession and sale of up to one ounce of marijuana for recreational purposes by persons 21 years of age and older. This legalization of marijuana, however, has no effect on the State of California’s laws regarding DUI while impaired by marijuana. Put bluntly, it is still against the law to drive stoned. 


Driving under the influence of any drug or any substance that can affect your ability to drive a motor vehicle, for that matter is a crime. This includes illegal narcotics, prescription medication, prescribed marijuana, and even over the counter medications. The crime is often referred to as DUI drugs, DUID, drugged driving, driving under the influence of marijuana or any combination of drugs.


California Vehicle Code section 23152(f) and California Vehicle Code section 23152(g) state this offense has the same consequences as driving under the influence of alcohol. The law indicates that it is unlawful for a person who is under the influence of any drug to drive a vehicle and it is unlawful for a person who is under the combined influence of any alcoholic beverage and drug to drive a vehicle.


Driving both under the influence of drugs and driving under the influence of alcohol are virtually identical laws. If it affects your nervous system in a way where you are impaired and you are in an altered state of consciousness then it is illegal. However, there are significant differences between the two offenses when being charged. California Vehicle Code section 23152(a) & (b) state that it is illegal to drive under the influence of alcohol, and to drive with a blood alcohol concentration of .08% or more. At the present time, California law does not specifically prescribe a prohibition on the amount of marijuana or any drug for that matter. Whether it is a prescription medication, marijuana, or controlled substance, California law does not actually prohibit any specific amount of a given drug in a person’s system, like it does with alcohol (.08%). Rather, the law simply prohibits a person from “driving under the influence” of a drug. In order for a person to be considered “driving under the influence” of marijuana, it must have such an effect on a person so that their mental or physical abilities “are so impaired that he or she is no longer able to drive a vehicle with the caution of a sober person, using ordinary care, under similar circumstances.”


Often times individuals who are suspected of driving under the influence of marijuana are put through the same balance or field sobriety tests as are driver’s suspected of alcohol intoxication or alcohol DUI. Usually, however, a “drug recognition expert” known as a “DRE” is usually called into the case when drugs are involved to examine the individual in question. A drug recognition expert is supposed to have special training related to identifying the symptomology of different types of drug use, and he/she can testify to the symptoms and effects of drugs or marijuana, and determine if the person is impaired in their opinion. 


A driver can be using marijuana or medication legally with a physician prescription, and yet if he or she is legally impaired, they can be charged with driving under the influence drugs according to CVC 23152(f). In fact, there are circumstances where sometimes over the counter products and medications, such as Benadryl, can be alleged to have caused a person to be “driving under the influence of a drug”. It is similar to alcohol in this regard. Alcohol is legal to possess and consume. However, it is not legal to drive while under the influence of alcohol.


In many ways, however, driving under the influence of marijuana is very different from an alcohol-related DUI in terms of the potential consequences in the department of motor vehicles (DMV). If a person is arrested because of an alcohol related DUI, then the DMV can impose an “administrative suspension” on their license if the person refuses the chemical testing or if there they have above a .08% blood alcohol. In a marijuana DUI situation, there is no actual amount of the drug that can cause an “administrative suspension”. Therefore, the DMV cannot impose an administrative suspension due to any amount of drugs found in a person system, however, they can still impose a suspension if the person was valid arrested for a marijuana DUI and they refused chemical testing. 


The chemical testing between marijuana DUI and alcohol related DUI also has some differences. Whereas law enforcement has the capability of testing for a person’s blood alcohol concentration (BAC) through the use of a breath test or breathalyzer, such a test will not show the presence of marijuana or drugs, at least for now. As a result, testing for marijuana or any other drug has to be administered by taking a blood test.


Elements of a Marijuana DUI

The offense of  driving under the influence of marijuana requires proof beyond a reasonable doubt of two elements:

·      Driving a motor vehicle

·      While under the influence of marijuana

The driving is the same whether it is an alcohol related DUI or a Marijuana DUI. Driving is usually proven through the testimony of the officer who observed the driving. However, in cases where the officer was not present, such as where there has been an accident or the car is parked, the driving element may be established through the testimony of passengers, witnesses, statements of the defendant, or — in some cases — through circumstantial evidence. This circumstantial evidence of driving under the influence of marijuana can consist of testimony that, for example, the defendant was seen behind the wheel of the parked car, the engine was warm, the keys were in the defendant’s pocket, etc. Circumstantial evidence is, of course, usually more susceptible to reasonable doubt in court than is direct evidence.

The second element in a driving under the influence of marijuana case, the defendant was under the influence of marijuana while he was driving,  requires proof of impairment, This is legally defined as being impaired to such an extent that he lacked the “ability to drive with the caution characteristic of a sober person of ordinary prudence under the same or similar circumstances.” This is, of course, a notoriously vague and subjective standard of proof.


Does Marijuana Cause Impairment?

Does marijuana in fact cause driving impairment? That is the million-dollar question. There is substantial evidence that it does not. A review conducted in 2002 of seven separate studies of over 7,000 drivers involved in auto accidents concluded that, “Crash culpability studies have failed to demonstrate that drivers with cannabinoids  in the blood are significantly more likely than drug-free drivers to be culpable in road crashes”. Two separate studies conducted by the U.S. Department of Transportation have reached similar conclusions. In one, researchers concluded that "although alcohol was found consistently and significantly to cause impairment, marijuana had only an occasional effect". In the other study, researchers found that “THC is not a profoundly impairing drug…It apparently affects controlled information processing in a variety of laboratory tests, but not to the extent which is beyond the individual’s ability to control when he is motivated and permitted to so so in driving.” See Does Marijuana Affect Driving Ability?”


Proving Impairment in a Marijuana DUI case

Driving impairment is usually proved in a DUI marijuana case through observations by the investigating officer, such as erratic driving, physical appearance, mental acuity, performance on field sobriety tests, the presence of marijuana or paraphernalia in the car, any incriminating statements, and the analysis of the driver’s blood for THC (Tetrahedroncannabinol).


An common practice in marijuana DUI investigations is to call in a drug recognition expert or DRE at the scene of the investigation or later at the police station or medical facility. A DRE is a police officer who has undergone a training program that involves the use of a standardized DRE drug impairment protocol of observations and tests for the recognition of drug influence and impairment, including impairment caused by marijuana. The protocols have, however, been the subject of criticism, and the training, skills and abilities of individual DREs vary widely. In the end, the test is necessarily somewhat subjective and dependent upon the training, experience and accuracy of the officer.


Marijuana DUI Blood Test

A driver who is arrested for driving under the influence is required by law to submit to blood test or a breath test. Refusal to submit to the test can be punished by an increased jail term and a longer license suspension. Since marijuana cannot be detected on a breathalyzer, drivers suspected of DUI marijuana are required to submit to having a sample of blood drawn. The blood is then later tested by a laboratory for the presence of marijuana or THC.  There are, however, periodic attempts to develop and use roadside tests for marijuana, just as hand-held breath alcohol tests were developed in recent years. The most recent of these DUI marijuana roadside tests have involved the investigating officer taking a swab of saliva from the driver’s mouth, and then using a device at the scene of the investigation to analyze the saliva for THC. And there are recurrent attempts to enact legislation to authorize this procedure. To date, these attempts have been unsuccessful. 


The problem with testing the blood for marijuana or saliva, however, is simple: analysis can only determine the presence of THC in the blood — it cannot determine either (1) when it was consumed, or (2) whether the amount would have caused any impairment. Inactive elements of marijuana can stay in a person’s blood for days, even weeks — long past when it could have any effects on the driver. And it has never been conclusively established how much marijuana can cause driving impairment — if it causes any impairment at all. In other words, it is difficult to establish any connection between the THC in the blood sample and the degree of driving impairment (if any).


Defenses to a Marijuana DUI

The three main defenses to a charge of marijuana DUI or driving under the influence of marijuana in California are as follows:

1.     The defendant was not driving.

2.     The defendant did not use marijuana.

3.     The defendant used marijuana but was not impaired at the time of driving.


While most people think of alcohol when they hear DUI, these charges don't always involve intoxication. In some cases, a person can be charged with DUI for driving while impaired by drugs, including marijuana. This may come as a shock to many people who think that so long as their drugs are legally prescribed to them, they cannot face any consequences. Unfortunately, you can be charged with DUI and be up against severe penalties for getting behind the wheel of a car after taking medical marijuana or any prescription drugs.

If you have been accused of DUI involving drugs, you cannot afford to try and fight your charges alone. Experience matters in cases like these, which is why you need to contact our Fullerton DUI lawyer right away. The Law Offices of Randall T. Longwith brings dedicated and aggressive defense to every case we take on.

CONTACT us today at (714) 606-6024 to set up a free consultation! 

Marijuana is arguably one of the most common drugs involved in DUI cases. However, it is also the most difficult to determine accurate impairment with. Why? The psychoactive component in marijuana, also known as THC, can be detected in a person's urine or blood for around for to five weeks after they have used it. There is also no real way to conclusively tell at what time the marijuana was inhaled or consumed.

If you have been arrested and charged with Marijuana DUI due to being impaired by drugs, you need to retain legal counsel immediately. Call our firm today for your free consultation!

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