DUI marijuana Laws in Colorado

Schmidt Law Group > DUI marijuana Laws in Colorado

Since Colorado decriminalized marijuana for both recreational and medicinal users there have been an increase in marijuana DUI arrests in the Denver metro area.  It’s important to remember an arrest is not a conviction.  Being accused of a crime is the officer’s version of what and why a crime has been committed. The standard used by the officer is probable cause, meaning it is more likely than not that you did what the officer said you did. It is a considerably lower standard that what must be proven to convict you.  Officers are taught that any amount THC in a persons system is impairing.  This mistaken belief has led to numerous false arrests and acquittals or not guilty verdicts by a jury.  This page seeks to provide education and information on Colorado DUI Marijuana Laws and defenses available to DUI marijuana charges

Colorado has two main statutes that cover DUI Marijuana charges.

  1.  42-4-1300(1)(f):  It is illegal to drive under the influence of marijuana.  Under the influence of marijuana means that marijuana affects you to a degree that you were substantially incapable, either mentally or physically to exercise clear judgment, control, or due care in the safe operation of car.
  2. 42-4-1300(2)(g):  It is illegal to drive while ability impaired due to marijuana.  While Ability Impaired means that marijuana affected your ability to drive to the slightest degree so that you were less able than you ordinarily would have been, either mentally or physically, to exercise clear judgment, sufficient physical control, or due care in driving

Unlike alcohol, Colorado has NO legal limit when it comes to active THC (referred to as Delta 9) in a person’s blood.  Colorado does have a presumption that anyone with over .5 ng/ml of Delta 9 THC could be under the influence of marijuana.  This presumptions means that IF considering ALL the evidence, including driving, balance, mental alertness and blood results, proves beyond a reasonable doubt that a person was driving under the influence of marijuana, then that person may be found guilty.  This is a very complicated presumption.  If you or someone you know is accused of Driving Under the Influence of Marijuana, we recommend that you contact an attorney that has experience in defending DUI-Marijuana Cases.  This firm has and does defend those of DUI Marijuana; please feel free to contact us for more information or look at our CASE STUDIES page.

The government has tried to take unsupported Standardized Field Sobriety Tests (SFST) to determine if someone is actively under the influence of marijuana.  The issue that many in the legal community have with SFST is that the SFST were made up by law enforcement for law enforcement.  This lends itself to a biased investigation.  Especially because the police will not consider other factors that could contribute to poor performance, such as tiredness, clumsiness, nervousness, attention deficient disorder, distraction, and lack of understanding.  You NEVER have to do SFST. My legal opinion is if you do the tests, you are helping the police make up reasons why you should be arrested for DUI. In fact, in my almost 10 year career, I have defended cases where a person passed the SFST and is STILL arrested for DUI. If you choose to do the tests or don’t do the tests you will be arrested, so why provide fuel for their fire?


The first thing to understand is that Marijuana DUI defense is different then any other area of DUI defense because the government treats it differently.  What other lawfully prescribed drug has the presumption above that Marijuana has?  For example, there are many lawfully prescribed drugs that a doctor would tell you not to drive until you know how this drug will affect you or recommend that you do not drive immediately after taking the drug.  This is because ALL drugs, including marijuana will affect each person differently.  A person may be under the influence of marijuana with just a small amount and someone else may not feel any effects.

If you have a certain amount of THC in your system, it does not mean you are guilty of DUI marijuana.

A blood level for THC without more is not helpful in determining impairment because the blood level does not always give an accurate account of impairment.  THC is fat-soluble and has been known to show up months after use. Additionally, THC could be hanging around in the blood long after use, which could result in residual THC, especially in frequent users.

Even if THC in your system is active it may not mean you are high or impaired for driving purposes. For example, if you are a regular consumer of marijuana, like other lawfully proscribed drugs, your baseline moves from zero up as your body may become adjusted to having the THC in your system.

For more information on marijuana use in Colorado:  check out this comprehensive consumer guide at COLORADO MARIJUANA LAW INFO

If you are fighting a DUI marijuana charge, please contact us (303) 747-4686 before you make any decisions or talk to the prosecutor. You may have a defense or could be entitled to a reduction in charges to a charge below that of DUI marijuana.