DUI Marijuana

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With the recent advent of legal marijuana in Colorado, there has been an emphasis for law enforcement officials to enforce DUI laws pertaining to drivers under the influence of marijuana. However, detection of marijuana in a driver is much more subtle than it is for a traditional DUI- alcohol case.

Marijuana v. Alcohol

First of all, unlike for an alcohol related DUI, Colorado is not a “per se” state when it comes to marijuana. For alcohol DUI cases, a person can be convicted of DUI if their blood alcohol level is .08 or higher. There is no such set limit for DUI- marijuana cases. The Colorado legislature created a “permissible inference” standard that sets out the law for DUI marijuana cases. In a trial for a DUI- marijuana case, the jury would be instructed in the following manner:

“As to the charge of driving under the influence and driving while ability impaired, a permissible inference that the defendant was under the influence of one or more drugs may be drawn if the amount of delta 9-tetrahydrocannabinol in the defendant’s blood at the time of the alleged offense, or within a reasonable time thereafter, as shown by analysis of the defendant’s blood, was five nanograms or more per milliliter in whole blood.

A permissible inference allows, but does not require, you [the jury] to find a fact from proof of another fact or facts, if that conclusion is justified by the evidence as a whole. It is entirely your decision to determine what weight shall be given the evidence.”

What this means is that a jury is allowed to make an inference that a person with more than 5ng/Ml of THC in their system is under the influence of marijuana, but the inference has to be supported by the other evidence in the case as a whole. This typically means that there must be evidence presented by the prosecution that there was actual impairment that was exhibited by the suspect when he was stopped. This can come in the form of impaired driving behavior or bad performance on standard field sobriety tests.

The reason that there is not a bright line, per se rule for marijuana is because some people may have more than 5ng/ML in their system and be perfectly safe to drive a car. This is especially true with frequent marijuana users, or medical patients who use marijuana regularly. Tolerance to the effects of marijuana can build over long time use, as it can with many other prescription medications. The legislature wanted to ensure that not everybody is placed in the same box for these cases, like we do for alcohol cases.

Proving a DUI Marijuana Case

Law enforcement officers also have a difficult time when determining if a person is impaired or not. It is not enough for a conviction to prove that a person used marijuana recently. Impairment due to consumption must also be proven beyond a reasonable doubt. If a person is capable of driving safely, performs field sobriety tests well, and is not exhibiting other signs of impairment, the suspect may be not guilty of DUI, even if their blood THC level is above 5ng/Ml.

Please note that, even though there is an absence of a per se law for marijuana, it is still advisable to wait an appropriate amount of time before driving a car after consuming marijuana. It is an impairing substance, and must be used responsibly, even by regular, practiced users.

These cases are very unique. We handle these cases routinely and are very well versed with the nuances that can accompany them. Our lawyers have taken many of these cases to trial and have had successful results. If you have been charged with DUI-Marijuana, call us immediately.


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