A Texas DWI prosecution does not require proof that the driver consumed alcohol. Marijuana, THC products, and other substances may become the basis for a DWI charge when prosecutors allege that the substance caused impairment. These cases often involve disputes about toxicology results, the timing of consumption, and the significance of police observations. At The Law Office of Alex Tyra, P.C., we review drug-related DWI allegations throughout Longview and East Texas.

Texas DWI Law Covers Drug Impairment

Under Texas Penal Code § 49.01, intoxication includes the loss of normal mental or physical faculties caused by a controlled substance, drug, dangerous drug, or another qualifying substance.

Texas law does not establish a general THC concentration equivalent to the 0.08 alcohol threshold for ordinary DWI prosecutions.

Therefore, prosecutors generally must rely on evidence of impaired faculties rather than simply pointing to a particular THC concentration.

The Limitations of Toxicology Evidence

Some cannabis-related substances or metabolites may remain detectable after their immediate effects have diminished.

A positive laboratory result does not necessarily establish that the driver was impaired at the time of operation.

We examine the substance identified, the testing method, the timing of collection, and whether the results support the prosecution’s allegations.

Reviewing the Officer’s Investigation

Officers may rely on driving behavior, physical observations, statements, or drug-recognition evaluations.

We evaluate whether those findings are supported by the recordings, medical information, and other available evidence.

Call The Law Office of Alex Tyra, P.C. for Your Free Consultation

If you were arrested for a marijuana- or THC-related DWI in Longview or East Texas, call The Law Office of Alex Tyra, P.C. at (903) 753-7499 for your free consultation.