How Many Tests Does it Take?

It is illegal to drive under the influence of marijuana in California. Those that do can face DUI charges and all the potential penalties of a California DUI. But marijuana DUI cases differ from alcohol DUI cases in some respects. The legal elements the prosecuting attorney must prove require a slightly different type of evidence and are held to a different legal standard. Chemical tests are still used to establish impairment, but, as we will see, those tests cannot accurately determine the exact timeline of drug use.

The Difference Between Marijuana and Alcohol DUI Cases

BAC—blood alcohol concentration or content—tests play a significant role in DUI cases. BAC tests—also called chemical tests—can be run using a breath, blood, or urine sample. Chemical tests used in marijuana DUI cases are run using a blood sample or sometimes urine. These tests can identify marijuana—and many other substances—in someone's blood. But they aren't precise enough to prove the defendant was driving while under the influence of marijuana. Because impairment while driving is an essential element the prosecuting attorney must prove, this poses a problem.

What's Needed for a Conviction?

So how does law enforcement gather evidence of drugged driving? Standardized field sobriety tests are frequently used to test physical measures, such as coordination and balance, both of which can be compromised by alcohol or drug use. It's easy for anyone to fail these tests, so poor performance doesn't necessarily mean you will be convicted. Some California jurisdictions are using mouth-swab drug tests to test for drugged driving roadside, much like a breathalyzer can do for alcohol. These test for the presence of drugs in saliva. But even if you test positive on a mouth-swab test, you will likely have to take a blood test to confirm the results.

Even though it's difficult to prove drugged driving, you better believe people are convicted of marijuana DUIs every day in California. To better understand the approach a prosecutor will take to prove a defendant was under the influence of marijuana when driving, let's take a look at the timeline of marijuana impairment and the tests that are reliable enough to meet the legal standard for use in criminal courts.

Timeline of Impairment

The average marijuana user experiences a high for about two hours after consumption. This number varies based on numerous factors. For example, consuming marijuana edibles can result in a delayed high with a longer life than smoking marijuana flower.

Blood and urine tests can be effective in detecting THC, marijuana's main psychoactive compound. But THC isn't processed like alcohol is. It is fat soluble and stored in fatty tissues. Once stored, it is released into the bloodstream at a relatively steady pace. Thus, someone could test positive for THC long after the high had fully subsided. Conversely, alcohol enters one's bloodstream as it is absorbed through the lining of the stomach and is broken down by the liver. Many factors can affect how long alcohol takes to enter and leave someone's bloodstream, but it is not stored long-term in tissues like THC.

To build a case against a defendant, the prosecuting attorney may rely on the results of standardized field sobriety tests and a blood test. He or she may also look to the police report, which may include information about the appearance and demeanor of the defendant and the contents of his or her vehicle. For example,

an officer's note that the motorist had red eyes and was easily distracted could be used as evidence he or she were impaired while driving. When combined, these various pieces of evidence can be enough for a conviction.

Even if there was a test that could prove when the defendant consumed marijuana, there is no standard for how much marijuana causes impaired driving. Herein lies the problem in prosecuting marijuana DUI cases. On the other hand, California's BAC threshold for DUIs is .08%. Chemical tests can determine someone's BAC with relative accuracy if the test is conducted according to protocol.

As you can see, marijuana DUI cases rely on evidence like standardized field sobriety tests and chemical tests. But there are many limitations of these types of evidence in accurately determining whether a motorist was impaired while driving. Therefore, if you are facing drugged driving charges in California, you need to be working with an experienced DUI defense attorney. An attorney can help you build a strong defense based on the evidence in your case.

Have you been arrested for a DUI? If so, contact attorney Christopher Martens and his legal team for expert counsel. Experienced in DUI defense, our Visalia area legal team can advise you of your options and help you take steps to prepare a defense, giving you a better chance of keeping your license. With over ten years of criminal defense experience, Christopher Martens will aggressively defend your rights at trial and help you get the outcome you want. Call our Visalia or Hanford, CA offices at 559-967-7386 or email us at [email protected] for a free consultation.