Principal Office
15110 Dallas Pkwy #400
Dallas, TX 75248
(972) 528-0478
15110 Dallas Pkwy #400
Dallas, TX 75248
(972) 528-0478
Years Defending Texans
Cases Dismissed
Criminal Cases Handled
Counties Served Across Texas
Available | Serving All of Texas
If you’ve seen a DWI checkpoint and wondered whether it’s legal—you’re right to question it.
In Texas, sobriety checkpoints are unconstitutional.
That surprises many drivers, especially when checkpoints still appear to operate. But Texas courts have made it clear: these stops violate state constitutional protections. And that matters for your case. If you were stopped or arrested at a checkpoint, the legality of that stop—and what followed—can often be challenged.
At the Law Offices of Richard C. McConathy, we know how to identify unlawful stops and move to suppress evidence when your rights were violated.
If you’re facing charges, working with an experienced Dallas DWI lawyer can make a critical difference in how your case is handled.
The Texas Constitution is stronger than the federal Constitution when it comes to protecting citizens from unreasonable searches and seizures. This doesn’t mean Texas courts will always provide more protection, but on DWI checkpoints specifically, Texas went further.
The Texas Constitution, Article I, §9, requires that no person shall be deprived of liberty without due process of law. Texas courts have interpreted this to mean that mass, suspicionless detention at roadside checkpoints violates a driver’s constitutional rights, even if there’s a general public safety interest.
In contrast, the U.S. Supreme Court has allowed federal checkpoints under certain strict conditions. However, Texas courts have said those standards are not enough under the Texas Constitution.
Texas courts, particularly the Texas Supreme Court and Texas Court of Criminal Appeals, have repeatedly held that sobriety checkpoints violate the right against unreasonable search and seizure. While the ruling doesn’t apply to every traffic stop or roadblock, it specifically bars “suspicionless” checkpoints designed solely to detect impaired drivers.
This means a police officer cannot legally stop your vehicle at a checkpoint just to check if you’re drunk. There must be another reason—like a traffic violation or a reasonable suspicion of criminal activity to justify the initial stop.
Police departments in Texas have adapted to the checkpoint ban. Instead of setting up stationary checkpoints, they conduct “rolling stops” or use other methods to encounter drivers and investigate suspected DWI.
A rolling stop occurs when officers patrol the roadway looking for signs of impaired driving—swerving, slow driving, erratic acceleration—and then stop individual vehicles based on those observations. A rolling stop is legal if the officer observed actual signs of impaired or reckless driving.
The problem: some officers use rolling stops as a pretense to stop drivers they suspect are leaving bars or driving late at night, without actual evidence of impairment. This is still unconstitutional.
Police can set up license checkpoints or registration checkpoints where they stop all vehicles briefly to check documentation. These are treated differently than sobriety checkpoints because the stated purpose is license/registration verification, not DWI detection.
However, if officers use a license checkpoint as a pretext to investigate DWI—keeping you there longer than necessary to perform FSTs (field sobriety tests) or smell your breath—that can violate your rights.
Even though sobriety checkpoints are illegal, you might still encounter a situation where police stop you at a roadside for DWI investigation. Knowing your rights is critical.
You do not have to perform field sobriety tests (FSTs). These are not legally required, and you can politely decline. The tests are subjective and designed to give the officer probable cause to arrest you.
Likewise, you can refuse a roadside breath test (the portable breathalyzer). However, refusing the official breath test or blood test at the station can have license suspension consequences under Texas’s implied consent law.
If you refuse field sobriety tests, the officer may still arrest you if they believe you’re impaired based on other evidence (speech, appearance, smell). Refusing the tests is not illegal and cannot itself be used as a reason to arrest you, but the officer may proceed based on other observations.
If you refuse the breath or blood test at the police station (the official test, not the roadside breathalyzer), your driver’s license will be suspended for 180 days (first offense) regardless of whether you’re convicted or acquitted. This is part of Texas’s implied consent law.
The key legal question is whether you are “seized” or just contacted. If the officer hasn’t restrained you, you can technically leave. Ask: “Am I free to leave, or am I being detained?” If you’re not being detained, you can walk away.
However, refusing to answer questions might look suspicious, so consult with an attorney before any roadside encounter if possible.
If you’re stopped, get the officer’s name and badge number, note the time and location, and take mental notes of their questions and observations. If there are witnesses, ask for their contact information. This information is crucial if your case goes to court.
Sometimes officers will use tactics that effectively operate like an illegal checkpoint, even if they don’t call it one.
If an officer stops you for a broken taillight but then keeps you detained for 20+ minutes while they investigate DWI, ask whether the detention became unreasonable. The stop must be brief and for its original purpose (fixing the traffic violation). Extending the stop to hunt for DWI evidence can violate your rights.
If an officer calls for backup or a K-9 unit without any reasonable suspicion of criminal activity beyond the original traffic violation, and the extended detention results in a DWI investigation, this can be challenged as an unconstitutional seizure.
If you were arrested at what amounted to an illegal checkpoint, our attorneys can file a motion to suppress evidence.
A motion to suppress challenges whether the evidence obtained during the stop was constitutional. If the initial stop violated your rights, any evidence gathered after that point (breath test, blood test, field sobriety test results) may be excluded from trial.
If the prosecution’s case relied heavily on that evidence, suppression can result in case dismissal or a much weaker prosecution case.
Once you raise a constitutional question about the stop, the burden shifts to the prosecution to prove the stop was legal. They must show the officer had reasonable suspicion or probable cause before detaining you.
You’ll have a hearing before the judge (not a jury) where:
If the judge agrees the stop was unlawful, the evidence is suppressed and often the entire case falls apart.
Here’s a practical example of how an illegal checkpoint-like stop can be challenged.
You’re driving home at midnight from a restaurant. Police have set up what looks like a sobriety checkpoint: officers are stopping every car at the same location. You’re stopped and asked if you’ve had anything to drink.
If there’s no other stated purpose besides checking for DWI (no license checkpoint, no registration checkpoint), this is an illegal sobriety checkpoint under Texas law. The initial stop itself was unconstitutional.
Our attorneys would file a motion to suppress, arguing:
If the motion succeeds, the case is likely dismissed or reduced to a minor traffic citation.
If you were arrested following an illegal stop or checkpoint, you have several paths forward.
If evidence is suppressed, prosecutors often dismiss the case. Without the breath test or blood test results, they typically cannot prove impairment beyond a reasonable doubt.
Our attorneys negotiate with prosecutors. Many prefer to dismiss rather than proceed to trial knowing their key evidence will be excluded.
If the case goes to trial and key evidence is suppressed, the jury only hears evidence the prosecution can present without the breath test or blood test. Witness testimony alone about your appearance or speech is often insufficient to convict.
Sometimes even with a weak case, prosecutors offer favorable plea deals (reduced charges, probation instead of jail). Our attorneys will evaluate whether accepting a plea is better than fighting at trial based on your specific situation.
Stay calm, be polite, and know your rights.
If arrested, call our firm immediately: 972-528-0116. We can begin investigating the stop and preparing challenges to illegal detention.
Whether you're facing a felony charge or fighting a traffic ticket, every case deserves serious attention. Get an experienced defense team in your corner now.
