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DWI Marijuana

Brian Foley is a DWI lawyer and criminal defense attorney in Conroe, Texas representing people charged with DWI Marijuana in Houston, Conroe, the Woodlands, and the surrounding area.

Can I be arrested for DWI on Maijuana? 

You can be arrested for DWI any time an officer believes you have lost the normal use of your mental or physical faculties based on the introduction of alcohol or a drug or “any other substance” into the body. 


The law is extremely broad in how it defines intoxication.  While it is true that there is no specific number that can be used to show a jury that a person was intoxicated based on a substance like marijuana, a prosecutor may still seek to convict a person of driving while intoxicated based on the person’s recent smoking of marijuana.​

Doesn't Maijuana stay in your system for a long time?

Marijuana can stay in your system for 30 days as detected in standard urine tests and up to six months if hair testing is completed.  However it is important to note that residual positive tests during a urine or hair follicle test will not generally go to prove that someone was being affected by the intoxicating nature of marijuana during the time that they are driving. 


To prove that someone was intoxicated based on marijuana and convict them of Driving While Intoxicated, the prosecution has to prove beyond a reasonable doubt that the person’s mental or physical faculties were impaired by the marijuana at the time of driving.

How do you defend DWI Marijuana blood test cases?

Officers take blood on almost every type of DWI case because the crime labs in the State of Texas can test for other substances including marijuana present in the individual’s blood.  When a lab report is returned and shows a positive test for marijuana in the person’s blood a closer examination is necessary.  A skilled defense attorney will know the difference between the types of positive readings. 


There are two main types of positive readings for marijuana in a forensic blood test.  THC metabolite, and Delta 9 – THC.  THC metabolite is the result of Tetrahydrocannabinol, the active ingredient in marijuana, being introduced into the body.  When your body begins to react with the THC it creates a metabolite.  A metabolite shows that THC was recently ingested by a person.  It does not show that the person’s mental or physical faculties were impaired by the THC.  On the other hand, Delta 9 – THC is a measure of the active THC in a person’s blood which is affecting the person’s faculties.  In Texas there is no legal limit but for example’s sake Colorado has a legal limit of 5 nanograms per milliliter of blood.  If your marijuana blood result indicates you have over 5 nanograms per milliliter it is of no legal consequence in Texas.  The prosecutor will be left in the same situation they would be in if you had refused a breath or blood test all together.  They will have to prove that you have lost the normal use of your mental or physical faculties.  The only difference is that they would have a test showing the presence of Delta 9 –THC as a substance which could possibly be to blame for poor physical or mental performance.

What is the punishment for a DWI Marijuana case?

A DWI first offense where the intoxicating substance is marijuana is a Class B Misdemeanor has a maximum jail time of 180 days and up to a $2,000 fine.  There are also DWI traffic fines imposed by the State that range from $3,000 - $6,000. 

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