If you or a loved one has been arrested for DWI in Montgomery County, Texas, it’s important to understand how the law defines “intoxication.”
Many people assume DWI laws only apply to alcohol, but Texas law casts a much wider net. Here are the top five things you need to know about intoxication under Texas law.
1. How Intoxication is Defined Under Texas Law
Section 49.01(a)(2) of the Texas Penal Code defines intoxication as not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of those substances, or any other substance into the body — or having a blood alcohol concentration (BAC) of 0.08 or more.
In simpler terms, the State has three ways to prove intoxication at trial:
- You didn’t have the normal use of your mental faculties.
- You didn’t have the normal use of your physical faculties.
- Your BAC was 0.08 or higher.
This gives prosecutors multiple avenues to pursue a DWI conviction in Montgomery County, making it crucial to have an experienced DWI defense attorney on your side.
2. Alcohol Has a Legal Limit, but Narcotics Do Not
While Texas law sets a clear legal limit for alcohol — 0.08 BAC — there’s no specific legal limit for substances like marijuana, prescription medications, or illegal drugs. Instead, officers rely on field sobriety tests, blood tests, drug recognition evaluations, and their own observations to determine if a person has lost the normal use of their mental or physical faculties due to drug consumption.
Here’s the bottom line: when prosecutors evaluate a drug-based DWI, they lean heavily on body camera and dash camera footage as the foundation of their case. They search for key moments that indicate a loss of mental or physical faculties linked to drug use.
3. Prescription Medications Can Lead to a DWI
Many people are surprised to learn that even legally prescribed medications can lead to a DWI arrest in Montgomery County. If a medication impairs your ability to safely operate a vehicle — even when taken as directed — you can be charged under the same DWI statute.
Common prescription medications associated with DWI charges include:
- Sleep aids
- Anti-anxiety medications
- Painkillers
- Muscle relaxers
Always consult your doctor or pharmacist about side effects before driving.
4. You Can Be Arrested for DWI Without a BAC Test
In certain situations, police can arrest a driver based solely on their observations or the results of field sobriety tests. While Montgomery County often enforces a “no refusal” policy to secure a warrant for a blood draw, officers have discretion to arrest based on signs of impairment, even without chemical testing.
Indicators like slurred speech, bloodshot eyes, unsteady balance, and the odor of alcohol or drugs can establish probable cause for a DWI arrest in Texas — even if no breath or blood test is performed.
5. Blood Testing for Toxicology Can Drastically Lengthen a Case
As of 2025, Montgomery County works with the Texas Department of Public Safety (DPS) to perform blood alcohol testing in Houston. However, if a sample requires toxicology testing in Austin, it can take six to nine months or longerto complete.
If you’re facing a DWI involving toxicology results, one of the smartest strategies to resolve your case quickly is to review body and dash camera footage. If the video shows marginal signs of intoxication, an experienced defense attorney may be able to persuade prosecutors to dismiss the case, rather than wait nearly a year for unnecessary lab results.
Final Thoughts: Hire a Montgomery County DWI Defense Attorney
DWI cases in Montgomery County, especially those involving drugs or prescription medications, are often more complicated than they appear. Without a specific legal limit for narcotics, these cases rely heavily on subjective evidence like officer observations and video footage. This makes it essential to have a skilled, local DWI defense lawyer who knows how to challenge weak evidence and protect your rights.
At Alsbrooks Law, we understand how local courts, prosecutors, and law enforcement operate. If you’re facing a DWI charge in Montgomery County, contact our office today for a free, confidential consultation. We’ll review your case, examine the evidence, and fight to get you the best possible outcome.