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Legal Marijuana: Driving Under the Influence?

by  on  Accident Attorney

Elections on November 5, 2013, showed that a number of other states are now willing to follow in the steps of Colorado and legalize the recreational use of marijuana. But as Coloradans know, legalization has brought with it a large number of issues that have proven to be difficult to resolve. Your Denver automobile attorney can attest that one of those issues was how to decide when someone is driving under the influence when they have been smoking marijuana, not drinking alcohol.

Prosecutors and state lawmakers pushed for laws that set a blood-level limit for THC, the key ingredient in cannabis. A driver who tests over the limit would be guilty of driving under the influence, just as with alcohol warns your Denver automobile attorney. However, marijuana activists argued that what works for alcohol does not work for marijuana since the two substances affect the body differently. They also argued that unlike alcohol, which is metabolized rather quickly in the body, traces of THC remain in a smoker’s system for a long time after use, and could lead to the false conclusion that the marijuana was recently ingested. Those in favor of a blood-level limit noted that tests exist which can determine the amount of “active” THC; i.e. THC in the bloodstream only hours after smoking.

Finally, on May 28th of this year, Colorado passed a new law setting legal limits on levels of marijuana in the bloodstream for drivers. A driver is presumed to be impaired if their blood test shows a level of THC of 5 or more nanograms per milliliter of blood. Washington, the only other state where recreational use of marijuana is currently legal, also adopted the 5 nanograms limit. Some states that allow the use of marijuana for medicinal use also use this limit for purposes of determining driver impairment.

Colorado’s new law makes the presumption that if a driver tests over the 5 nanograms per milliliter of blood limit, he/she is “under the influence.” But unlike with alcohol, the presumption can be rebutted with evidence put on by the defendant. The law only sets up a “permissible inference” not a “per se measure,” allowing a person charged with driving under the influence and who fails the blood test to still make the case that he or she was not impaired while driving. “Per se” measures function very differently in that they function as proof of impairment. A common example of this is the well-known .08 limit for blood alcohol content.

Because Colorado’s law establishes a rebuttable presumption, critics argue that the law was not necessary. Detecting marijuana DUIs by police observing driver impairment would ultimately lead to the same result: prosecutors arguing the driver was under the influence and the driver arguing that he/she was not impaired.

As mentioned, if the November 5th elections are any indication of the future of legal marijuana, defining driving under the influence and what constitutes impairment for marijuana users will continue to be a controversial issue for many years to come. For more information on Colorado’s new law, or if you have questions regarding a DUI charge involving marijuana, contact your Denver automobile attorney at Levine Law.