Drivers in California who operate a vehicle after using marijuana can be charged with driving under the influence (DUI). Charges for a DUI often require police officers to demonstrate the presence of marijuana in a driver’s bloodstream, which isn’t always an accurate correlation to intoxication.
At Simmrin Law Group, we’ve helped hundreds of people reduce or eliminate drug charges so you can feel confident when you work with our team. Our Los Angeles DUI lawyers explain how police test for marijuana DUIs and how we can help if you’re facing charges.
Chemical Tests for Marijuana in California
There are three common tests that police use to screen for marijuana. Law enforcement officers who suspect a driver is committing a marijuana DUI may request that the driver complete a:
- Blood test
- Saliva test
- Urine test
The above methods can be used to determine if a driver used the drug. However, they all have serious drawbacks. The drug does not dissipate from a person’s system as quickly as alcohol. Marijuana tests often cannot tell:
- How long ago a driver used the drug
- How much of the drug a driver used
A criminal defense lawyer in Los Angeles may be able to dispute the results of a drug test after you are arrested.
Blood and Saliva Samples for DUI Usage in California
Blood and saliva tests are designed to detect THC (delta-9-tetrahydrocannabinol) in a driver’s system. THC is a psychoactive substance found in marijuana.
You should be aware that California does not use a maximum legal limit for THC. Without a legal limit, any amount of THC in a driver’s system could result in DUI charges.
Blood samples are used more commonly than any other chemical test in marijuana DUI cases. Saliva tests, on the other hand, are often used as a part of preliminary screening. Additionally, there may be a discussion of whether or not a saliva test will be admissible in court if you are charged with driving under the influence of drugs (DUID).
Urine Samples for Marijuana Usage in California
In California, urine samples are not used as frequently as blood and saliva tests. However, a police officer may request that you complete these assessments in some situations. Urine samples also don’t detect if THC is present; they only look for inactive metabolites associated with drug usage.
However, you should be aware that these metabolites only indicate that someone used the drug. They cannot show that a driver was impaired. They also remain in a person’s system for a long time after a driver uses it. The metabolites may show up on a urine test for up to a month after someone uses marijuana.
According to a National Institute of Justice study, field sobriety exams and biofluid testing, such as urine, blood, and saliva, don’t correlate with intoxication. When our team of DUI lawyers takes on your case, we’ll make sure to bring up this point. To have a valid reason to charge you, police must show that the drug prevented you from driving safely.
Officers Look for Physical Evidence of Drug Usage
In addition to conducting chemical tests, a law enforcement officer may look at a driver’s behavior and physical state when making a marijuana DUI arrest. Police officers throughout California are trained to look for:
- Rapid breathing or a fast heart rate
- Dilated pupils or red eyes
- The smell of marijuana
Additionally, you may be asked to complete a field sobriety test (FST) if an officer suspects you are committing a DUID. Note that you may legally refuse to complete an FST if you are:
- Not legally arrested
- Over the age of 21
- Not on DUI probation
Failure on an FST can be taken as evidence that a driver is impaired. Finally, police officers may use the presence of drug paraphernalia associated with marijuana usage as proof that a driver is operating a vehicle while under the influence.
Will a Medical Card Protect Me from a DUI Charge?
In California, having a valid medical marijuana card generally will not prevent you from being charged with a DUI if you are found to be driving under the influence of marijuana. Under California law, it is illegal to drive a vehicle if you have any detectable amount of THC, the main psychoactive compound in marijuana, in your system.
Even if you have a medical card, prosecutors can still use evidence like field sobriety test results, drug recognition expert testimony, or chemical testing to argue your driving was impaired to any degree by THC consumption.
The medical marijuana defense is weak in California DUI cases. Having a recommendation may provide context for why you tested positive. However, the focus is solely on impairment, not possession or usage itself. Prosecutors only need to prove THC affected your ability to drive safely.
How a Lawyer Can Help You if You’re Suspected of a Marijuana DUI
While marijuana DUIs may present some advantages in arguing reasonable doubt compared to alcohol cases, it’s still important to have an experienced DUI lawyer on your side. Here are some key ways our team at Simmrin Law Group can help:
- Filing motions like suppressing unreliable roadside tests, challenging lab procedures, and getting charges reduced preemptively.
- Understanding toxicology allows questioning lab technicians and police on how specific tests correlate to actual impairment.
- Developing theories through our investigations and witnesses introduces other possibilities for THC beyond impairment.
- Identifying weaknesses in the prosecution’s case and aggressively pointing out gaps in evidence during cross-examination.
- Guiding you on the next steps, maintaining privacy, and advising on record sealing in the event of acquittal or dismissal are also invaluable legal support.
Speak to a Lawyer if the Police Tested You for a Marijuana DUI
The police can use saliva, blood, and urine tests for a marijuana DUI. You may also be subjected to FSTs during a DUI traffic stop. The team at the Simmrin Law Group can help you after you receive the results of these tests.
Contact us for a free consultation and learn more about how police screen for drug DUIs.