The truth behind the odor of marijuana

For years Texas courts, under the mistaken belief police officers possess superhuman–like senses of smell, have permitted invasive search and seizures based on the odor of marijuana alone. This low threshold has morphed into a catch-all phrase for vehicular searches and subsequent drug arrests. This is particularly troublesome when you read statements like the one given by

Peter Keane, a former San Francisco Police commissioner, in an article for the San Francisco Chronicle, titled “Why Cops Lie”:

Police officer perjury in court to justify illegal dope searches is commonplace. One of the dirty little not-so-secret secrets of the criminal justice system is undercover narcotics officers intentionally lying under oath. It is a perversion of the American justice system that strikes directly at the rule of law. Yet it is the routine way of doing business in courtrooms everywhere in America.

Find a marijuana case and you will find a police report citing the odor of marijuana as the basis for probable cause. Find a cocaine case and you will find a police report citing the odor of marijuana as the basis for probable cause. This is despite any cannabis being found. This catch-all phrase for probable cause is not only subjective, but unverifiable without any reliable standardized training.

Walk into a medicinal marijuana shop and you will find jars full of marijuana. There is the Tahoe-OG that provides a syrupy smell and taste. There is Bubblegum Kush, that tastes and smells as the name suggests. There is the Blueberry strain and the Vanilla strain. The point is the odor of marijuana can take on many different scents.

The make-up of marijuana consists of different cannabinoids, flavonoids, and terpenoids. How much of each varies.   The nearly 200 different types of Terpenoids or Terpenes give marijuana its smell. These terpenoids can be found in our everyday fruits, vegetables, herbs, spices, and hops.

Terpenes	Aroma	Also Found In
Alpha-Pinene	Pine	Pine Needles, Rosemary, Basil, Mosley, Dill
Myrcene	Earth, Herbal, Citrus	Mango, Lemongrass, Thyme, Hops
Limonene	Citrus	Fruit Rinds, Rosemary, Juniper
Caryophyllene	Pepper	Black Pepper
Linalool	Floral	Lavender

The fact marijuana may smell similar to many of your kitchen spices, a pack of bubblegum, or a pine tree isn’t the only issue. The actual ability to smell marijuana from a vehicle was called into question by a peer-reviewed journal article, entitled “Marijuana Odor Perception: Studies Modeled From Probable Cause Cases”, published in the Law and Human Behavior (Vol. 28, No. 2, April 2004). Based on two different studies this article wrote, “… a blanket acceptance of testimony based upon reported detection of odors for probable cause is questionable…”. In the first of two studies, researchers recreated a situation where, during a normal traffic stop, an officer would say he detects the odor of packaged marijuana, located in the trunk of a car. The study discovered that individuals in this officer’s position were unable to accurately detect marijuana odor. In fact, the presence of marijuana was incorrectly identified 90% of the time.

Fortunately, there have been steps made in the right direction. Recent case law in Texas declared the odor of marijuana alone insufficient probable cause for searching a home. Other states have revisited the olfactory questions as it relates to marijuana in a vehicle. Massachusetts, for example, held due to the medicinal stature, the smell of marijuana is ‘no longer indicative of criminal activity’ and therefore no longer justifies probable cause. With the recent passage in Texas allowing the limited use of medicinal marijuana, searches and arrests based on the odor of marijuana are ripe for challenge.

As history continues to be made and states across the nation set out to enact some form of marijuana legislation, the requirement for probable cause needs to keep pace.

Next time you are in your kitchen, open up a bottle of oregano, give it a smell, and you will understand.