Drug DWI Attorney in Houston

How Houston Police Investigate Drug DWI Cases

There’s no breathalyzer for drugs. Law enforcement instead relies on a combination of officer observations, field sobriety tests, Drug Recognition Expert (DRE) evaluations, and blood or urine toxicology. Each of these carries its own vulnerabilities.

A DRE evaluation is a 12-step protocol that includes pulse rate measurement, eye examinations, pupil measurement under varying light conditions, muscle tone assessment, divided-attention tests, and checks for injection sites. The conclusions rest entirely on the evaluating officer’s subjective observations and non-medical training. That isn’t equivalent to a physician’s assessment, and that distinction matters in court.

After a drug DWI arrest in Houston, police typically seek a warrant for a blood draw. Refusing doesn’t eliminate consequences. Texas’s implied consent law means refusal can trigger automatic license suspension. The timing of that blood draw is also critical: drugs metabolize at different rates, and the gap between when you were driving and when the sample was taken affects the reliability of the results. THC from marijuana, for example, can remain detectable in blood for days or weeks after any impairing effect has worn off. A positive test isn’t proof of impairment at the wheel.

Penalties for a Drug DWI Conviction in Texas

The consequences escalate sharply with prior offenses, and Texas has no look-back period for DWI convictions, meaning any previous DWI on your record, regardless of how old it is, can enhance your current charge.

• First offense (Class B misdemeanor): Up to 180 days in jail, a fine up to $2,000, and a license suspension up to one year
• Second offense (Class A misdemeanor): Up to one year in jail, a fine up to $4,000, and a license suspension up to two years
• Third or subsequent offense (third-degree felony): Two to 10 years in prison and a fine up to $10,000
• Child passenger under 15 present: A separate state jail felony charge in addition to the DWI itself

A drug DWI arrest also triggers the Administrative License Revocation (ALR) deadline: you have 15 days from the date the suspension notice is served to request a hearing. Miss that window and your license is automatically suspended on day 40.

These arrests frequently create a second layer of jeopardy. If officers find controlled substances during the search incident to your arrest, you may also face charges under Texas’s Controlled Substances Act. Penalties vary by penalty group and quantity and can compound your exposure significantly.

Defense Strategies in Drug DWI Cases

Drug DWI cases are often more defensible than alcohol DWI cases because the evidence is more subjective. The prosecution must prove actual impairment, not merely that a substance was present in your system. That distinction creates real openings for a prepared defense.

• Challenging the traffic stop: Whether the officer had reasonable suspicion to pull you over in the first place
• Attacking DRE reliability: Whether the evaluation was fully and properly completed, and whether the officer’s conclusions are consistent with the actual blood test results
• Disputing the blood evidence: Chain of custody gaps, improper collection, delayed testing, and whether detected compounds are active metabolites causing impairment or inactive residue
• Arguing the timing gap: The difference between what was in your system at the time of testing versus at the time of driving
• Medical explanations: Conditions including fatigue, anxiety, diabetes, or neurological disorders can produce behaviors officers misread as drug impairment