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Missouri Marijuana and Drug DWI

The Missouri statute regarding driving while intoxicated, RSMo 577.010, makes no distinction between alcohol or drug intoxication. It simply reads, “A person commits the offense of driving while intoxicated if he or she operates a vehicle in an intoxicated condition.” Intoxicated condition is described in RSMo 577.001 as when a person is under the influence of alcohol, a controlled substance, or drug, or any combination thereof. 

Many facts about alcohol DWI will be valid for marijuana and drug DWI. Feel free to check out other pages on this site to get a general idea of the process and possible outcomes. More information is also available on the Beerup Law blog. There are, however, some significant differences between drug and alcohol DWIs. 

Abuse and Lose 

Missouri Abuse and Lose law generally applies to drivers under the age of 21, but an important provision applies to adults with marijuana and drug DWIs. Per the Missouri Department of Revenue, anyone 21 years or older may have their driving privilege revoked for one year for possession or use of drugs while driving.  

Abuse and Lose makes it very important to hire an experienced criminal defense attorney if you have a marijuana or drug DWI. The court will try to revoke your license for one year. An attorney who regularly handles these cases can fight this revocation, but it is difficult. 

Drug Recognition Experts

Most police officers have at least a general familiarity with alcohol DWI law, and many departments have an officer they consider an alcohol DWI expert. The same is not true for drug DWIs. Very few officers are considered a Drug Recognition Expert (DRE). An officer must have a proven record of DWI arrests and complete at least 80 hours of training in addition to their regular DWI training to be officially recognized as a DRE. Less than half of the police agencies in Missouri have a DRE.

The scarcity of DRE officers can work both ways. Sometimes a drug DWI is handled by a police officer with little training. Often, a defense attorney can use mistakes in these cases to achieve a favorable outcome. Other times, a drug DWI is handled by a DRE. They conduct a 12-step testing process that can take over an hour, and evidence of intoxication is thoroughly cataloged. These types of cases are considerably harder to fight. 

Blood Levels 

Testing standards for alcohol DWIs are well established. A blood alcohol level of 0.08% or higher is statutorily held to be proof of intoxication. No such standards exist for drug DWIs. Some states have attempted to set per se limits for marijuana impairment, usually 5 ng/ml. A per se standard is something that stands on its own without further proof, like the 0.08% alcohol level. These standards are not scientifically justifiable with marijuana or drug DWIs (see here for more). 

Police officers and prosecutors often take the position that they need only show the presence of drugs on a test to prove a DWI. This is simply not true. Just as a blood alcohol level of 0.03% would not be proof of intoxication, the mere presence of drugs in a person's system is not enough to conclusively show impairment. 

The lack of per se levels for drug intoxication places added importance on police officers' drug influence evaluations. As discussed above, these evaluations can be hit-or-miss. Criminal defense lawyers are generally very familiar with the standard alcohol field sobriety tests like horizontal gaze nystagmus, walk and turn, and one-leg stand, less familiar with drug field sobriety tests like modified Romberg, and even less familiar with the complete Drug Evaluation and Classification Program standardized 12-step evaluation. 

The Defense Attorney's Role in a Drug DWI

If you are facing a drug DWI, hiring an attorney with experience is essential. The lack of a gold-standard per se blood or breath test for drug intoxication means law enforcement will be forced to rely on other proof to show intoxication. You need a lawyer who can examine that proof to find the errors.  

A good defense attorney will file a motion to force the state to disclose all evidence in the case and examine that evidence for law enforcement mistakes. Finding errors can be difficult when a Drug Recognition Expert is involved. Still, in a surprising number of instances, police officers think that showing any proof of drug use proves intoxication. These cases will sometimes have weak observations or field sobriety tests. A good negotiator can use this to advantage and achieve a favorable outcome. 

If you are facing a marijuana or drug DWI, call attorney Ruth Beerup at 636-940-1111. She has defended clients in these types of cases for over 25 years and achieved outstanding results.


Case evaluations are free and you will always talk directly with Ruth. She can tell you exactly what charges you are facing and give you some options on how to deal with them. So, even if you don’t hire her for your case, you can still get a better understanding of your situation. Call 636-940-1111 now.