Many people are surprised to find that that it is just as easy to get a DWI from marijuana as it is from alcohol. It is possible to get a DWI from many different prescription drugs and illegal drugs, including marijuana. Police will be begin to suspect intoxication due to marijuana if, 1) they smell marijuana smoke or 2) marijuana is found in your car or on you, or 3) they suspect that you are intoxicated but a breath test comes up negative for alcohol.

Some Problems with These Cases

There are many problems with proving that a person is guilty beyond a reasonable doubt simply because of marijuana. Beyond a reasonable doubt is a big hurdle in any case, and I spend a lot of time and effort imprinting that notion on juries. I bring it up early and often during trial. It is very important to retain an attorney who knows how to expose weakness with these cases, and how to raise reasonable doubt.

Does Marijuana Really Affect the Ability to Drive?

For one thing, there is disagreement regarding how much, if any, marijuana impacts a person’s ability to drive a motor vehicle. There is not even a scientific consensus that marijuana impairs driving at all. Another problem with marijuana is determining how long ago a person consumed the substance. Alcohol is absorbed and eliminated by the body’s liver in a fairly measurable and linear way. This is not the case with marijuana. How the body metabolizes THC-COOH varies dramatically from person to person. THC-COOH is the main metabolite that formed in the body after a person consumes cannabis. This is what blood and urine tests are looking for.

Legalization Coming to Texas? Just Don’t Hold your Breath

Many states like Colorado, Washington, Oregon, and others are beginning to legalize marijuana, and it is exciting to see how that develops and spreads as different states decriminalize marijuana. Other states will follow, but some don’t seem ready to make this plunge. This is Texas, of course. That means marijuana is still illegal, and will remain illegal for the foreseeable future.

Texas Penal Code 49.04

Texas does not have a defined limit for how much marijuana in a person’s system translates to a presumption of intoxication. Most if not all of the various States which have legalized marijuana have also adopted per se limits. Per se limits have resulted in stricter enforcement in marijuana-related DWI offenses. A per se limit is fancy legal just means that there is a legal limit to the amount of marijuana allowed in a person’s system. Much like alcohol. All states have a per se limit of alcohol at 0.08%. Marijuana levels can be determined by testing a sample of a person’s blood. This is measured the same way that alcohol is measured. This process is called gas chromatography.

Loss of Physical or Mental Faculties

Texas does not have per se limits for marijuana. In Texas, the State must prove beyond a reasonable doubt that you lost either your physical or your mental faculties while you were driving a motor vehicle. This language comes from Chapter 49 of the Texas Penal Code.