Menu

Still Searching For A DUI Test For Marijuana


16 patrol officers from the states of Colorado and Wyoming gathered in a hotel conference room in the State of Denver to do an experiment. In order to shop for marijuana, they got dressed in street clothes and went to nearby dispensaries. Officers present in the conference room were those who had duties assigned to keep the roads safe. They required a formal pot education for this. They needed to learn to identify the different marijuana products and paraphernalia.

Chris Halsor was among these patrol officers who is a Lawyer and a former prosecutor as well. Halsor said that there are more marijuana dispensaries in Colorado than Starbucks shops. The consumption of cannabis is legalized but driving while intoxicated with it is not.

The challenge they are facing is that although the use of cannabis is legalized, police still do not have a chemical test to assess how the drug affects the brain. There are certain tests that can detect the amount of alcohol in the blood but there is no broadly approved standardized amount in the breath or blood that can help identify whether an individual is under the influence of marijuana or not. Some scientists are working to create a test to detect it which can be used as a standard as well.

Tara Lovestead is a chemical engineer. She has been working to find out a standard for the detection of marijuana. She said, “We like to know the human error and the limitations of the human opinion.” She also said that the stuff down the street cannot be used.

Finding a standard for blood or breath test is also difficult because of the psychoactive chemical found in cannabis i.e. delta-9-tetrahydrocannabinol a.k.a. THC. Supposed intoxication of cannabis can be found using a THC test. According to this test, an individual is impaired if 5 Nano grams of THC per millimeter of blood is detected. However, scientists, including Lovestead, are of the view that the mentioned cutoff does not have a meaning. “We just don’t know whether or not that means they are still intoxicated, or impaired or not,” said Lovestead. “There’s no quantitative measure that could stand up in a court of law.

Therefore, determining from a blood or breath test that someone is under the influence is very much difficult.

The main psychoactive chemical in cannabis gets dissolved in the fat. Therefore, the time it stays in the body of a person varies from person to person. Factors like gender, amount of body fat, frequency of usage, the method of consumption and the variant of cannabis consumed can determine the length of time it stays in the body.

Marilyn Huestis, who is a toxicologist, said, “It shocked everyone, including ourselves, that we could measure, in some of these individuals, THC in the blood for 30 days.” The bodies of the participants accumulate THC that leach out slowly, even if they have not smoked marijuana for a period of about a month. Researchers have found the level of marijuana to be 5 Nano grams for individuals who use marijuana regularly but have not used it for several days.

On the other hand, some studies found no traces of cannabis in the blood of regular smokers. Therefore, it is determined that blood tests do not provide an accurate measure of cannabis present in the body. Scientists have shifted their focus towards breath tests in order to find something useful.

THC and cannabinoids get degraded promptly and do not appear in the breath in large amounts. According to Tara Lovestead, metabolites should be looked for in the breath. Lovestead was of the view that a test that detects metabolites will reduce the possibility of making someone positive from inhaling secondhand smoke.

The police officers who attended the seminar were allowed to watch a video in which people were heating concentrated marijuana and inhaling the vapors. They were given a visit to a local marijuana dispensary where they reviewed hollowed-out cigars filled with marijuana. In order to test the skills of these officers, they were sent to examine some volunteers who were smoking pot inside an RV.

All of the volunteers smoked a large amount of pot in the RV. The cops had to do some tests on the participants in order to determine whether they would need to arrest these people in real life. One of the participants named Christine did not do well on tests including balancing, remembering instructions and estimating time. The officers agreed on arresting individuals showing similar signs on tests in real life.

In previous courses, officers agreed on labeling a volunteer as under the influence while in fact the volunteer did not smoke at all. Therefore, the officers had been making educated guesses only. The judgements officers make can also yield false positives and negatives like the THC tests.

Lovestead published a paper in which she found out the vapor pressure of THC. She is of the view that finding and standardizing the measurement is although a small step, but an important one, that can help provide a more objective route towards determining high drivers. The course introduced by Haslor can provide useful information to the officers. At the end of the class, they are at least aware of smell of the pot strains like Skunk Dawg, Hippie Chicken and Chunky Diesel.

“Yeah,” said Gurley who was one of the officers. “It smells like the bottom side of a rock.”

Share this Article
Matthew V. Portella

About the Author

The Law Office of Matthew V. Portella, LLC. is a full service law firm where attorneys with their extensive experience provide strong & Aggressive defense against DWI/DUI & Criminal cases.