One of the many myths surrounding the passing of Initiative 502 was that for the first time, it became illegal to drive under the influence of marijuana. Truth is, it has always been illegal to drive under the influence of any intoxicating substance, whether that is alcohol, marijuana, cocaine, or any other prescribed or illegal drug. The method by which a marijuana DUI is investigated has not changed with the passage of I-502. The only true change to the law is how a person can be convicted.
Prior to the passage of I-502, the prosecution had to prove that the driver “was under the influence of, or affected by” the drug (in this case, cannabis). Washington’s new legislation still permits the prosecution to prove its case in that fashion, but the law has added another prong to the statute by which a conviction can be obtained. The only significant change to impaired driving laws is the creation of a “marijuana per se” impaired driving. This limit, set at 5ng/100ml of blood, provides the prosecution another way to prove an impaired driving case, similar to the .08 grams of alcohol that has become synonymous throughout this country as the “legal limit.” In reality, for both alcohol-based and marijuana-based DUIs, the prosecution can still obtain a conviction even if the person tests under the per se limit — if they can prove beyond a reasonable doubt that the individual was “affected to an appreciable degree,” regardless of what level is found in their breath and/or blood.
There are many similarities between an alcohol DUI and a marijuana DUI. However, there are also some differences. Read more