While we’ve been on the topic of DUI of marijuana, it only seemed appropriate to talk about some of the legal defenses that may be raised with this charge.
Just like with a DUI of alcohol, the officer must have probable cause to believe that you are driving while under the influence before he or she can arrest you. The officer has probable cause when they have apparent and trustworthy facts that would lead a reasonably intelligent and prudent person to believe that the driver is driving under the influence. The information that officers use to “find” probable cause is poor driving, the smell of marijuana, blood shot watery eyes, slowed speech, poor performance on field sobriety tests, and admissions by drivers that they have ingested marijuana. Only after a lawful arrest must a driver submit to a chemical test. If an officer makes an unlawful arrest because they didn’t have probable cause, the results of a chemical test showing the presence of marijuana should be inadmissible.
This is precisely why I always advise my clients to not say anything to law enforcement and decline field sobriety tests. Not only is it your right to do so, it preserves the argument that the arrest was unlawful and therefore evidence of marijuana use from a chemical test is inadmissible.
While the defense of an unlawful arrest applies to both DUI of alcohol and DUI of marijuana, there are a few defenses that are unique to a DUI of marijuana.
Unlike alcohol, Delta-9-tetrahydrocannabinol (THC), the psychoactive component of marijuana stays is a user’s system long after ingestion. Therefore, a person can test positive for THC well after the person smoked marijuana and well after the person was intoxicated, sometimes as much as weeks afterwards.
There is a strong correlation between blood alcohol content and intoxication. In other words, law enforcement knows that if a person has, for example, a blood alcohol content of 0.12 percent, it is highly likely that the person is intoxicated and unfit to drive a vehicle. The correlation between THC and intoxication, on the other hand, is not as clear. THC is measured in nanograms per milliliter of blood. For example, Colorado, which have legalized recreational marijuana, has made it illegal to drive with 5 nanograms of THC per milliliter of blood. A person, however, can have 5 nanograms of THC per milliliter of blood in their system weeks after smoking marijuana and certainly well after the person is unfit to drive. Therefore, there is the defense that you are not driving under the influence of marijuana even though you may have THC in your system.
Should California approve the roadside test to determine whether a person has ingested marijuana “recently,” prosecutors still need to prove that the use of marijuana actually impaired a person’s ability to drive to secure a DUI of marijuana conviction. If the driver refuses field sobriety tests, there’s not much evidence, other than the driving pattern, that a person’s ability to drive was impaired. Therefore, another realistic defense is that the person’s driving was not impaired even though they had recently smoked marijuana.
In any event, hiring a qualified California DUI attorney is essential to be able to successfully assert any of the aforementioned legal defenses to a California DUI of marijuana charge. As you can see, they are quite complex and I’ve only scratched the surface.