DWI Blood-Draws Require a Search Warrant:

The Texas Court of Criminal Appeals (Tex. Ct. Crim. App.) ruled on November 26, 2014, that if a person suspected of a DWI offense refuses to provide a blood specimen pursuant to the Implied Consent and Mandatory blood-draw provisions of the Texas Transportation Code, then police must obtain a search warrant.  The Court stated:

We hold that a nonconsensual search of a DWI suspect’s blood conducted pursuant to the mandatory-blood-draw and implied-consent provisions in the Transportation Code, when undertaken in the absence of a warrant or any applicable exception to the warrant requirement, violates the Fourth Amendment. State v. Villarreal (No. PD-0306-14).

This ruling follows Missouri vs. McNeely –an April 2013 United States Supreme Court case that held the Fourth Amendment requires police to obtain a search warrant to get a sample of your blood if there is no emergency or other exigent circumstances.   Click here to read our previous post on McNeely and its implications.


David Villarreal was arrested on suspicion of DWI after committing a traffic offense.  Police ran Mr. Villarreal’s criminal history and determined that he had two prior felony DWI convictions.  Villarreal did not consent to a blood draw.  Nevertheless, the arresting officer obtained a blood sample without a search warrant pursuant to Texas Transportation Code 724.012(b), which requires a mandatory-blood-draw for people who have two or more DWI convictions.  The tests showed that Villarreal’s blood-alcohol concentration (BAC) was .16–twice the legal limit.

DWI Blood Draws
DWI Blood Draws

The court of criminal appeals held that the officer should have obtained a search warrant to draw Villarreal’s blood.  The court noted that Texas’s statutory implied consent statute and mandatory-blood-draw provisions did not trump the Fourth Amendment of the United States Constitution that ordinarily requires police to obtain a search warrant–absent a warrant exception of course.  Because police did not comply with the warrant requirement, it held that the evidence from the blood draw was inadmissible.

News Coverage of Case:

This case has generated significant news coverage.  Click here, here, and here for more information on this case and its implications.

So what does this mean for me?

If you are arrested on suspicion of DWI in Texas, then police should ordinarily get a warrant-absent an exception to the Warrant requirement of the Fourth Amendment–to draw your blood if you decline to voluntarily provide a sample.

As a practical matter–police in San Antonio have been obtaining warrant’s to draw blood from suspected DWI offenders since April 2013, when the Supreme Court handed down Missouri vs. McNeely.

Final thoughts–law enforcement will still pursue their “No Refusal” initiatives–where police obtain search warrants to draw your blood if you are suspected of DWI and you decline to provide a breath or blood specimen.

But it is important to know your rights.  If you are detained or arrested on suspicion of DWI–then remember you have the right to remain silent and a right to speak with an attorney before you answer any questions.  This is important because anything you tell the officer can and will be used against you at your DWI trial.

Also, never fight with an officer or resist arrest.  You are only asking for more trouble if you do.  Remember–you will get your day in court–and an opportunity to confront and cross-examine your accuser–i.e., the arresting officer–if you choose to go to trial.

PHONE:  210.733.7575

Article Name
Does the Fourth Amendment require police to obtain a search warrant before they draw my if I am suspected of Driving While Intoxicated in Texas?

Author: Genaro Cortez

Hi! I am Genaro Cortez, a DWI Attorney in San Antonio, Texas. This blog provides information on frequently asked questions about DWI charges and criminal defense.